Search published articles


Showing 24 results for Drought

Adel Solimani, Hassan Afrakhteh, Farhad Azizpour, Asghar Tahmasebi,
Volume 3, Issue 2 (5-2016)
Abstract

The latest report of the Intergovernmental Panel of Climate Change (IPCC) on climate and global warming Indicates that climate change and global warming in particular is one of the most important challenges of the world and drought, as a consequence of climate change around the world, has always influenced the many countries, including Iran. However, it seems that the climate changes, particularly in the West and Iran, especially among farmers and rural communities vulnerable to the effects of economic, social and environmental impacts that are more significant. In other words, Continuous droughts are faced villagers and farmers with various problems and challenges, In this regard, villagers Choose the local and specific strategies in the face of this creeping disaster that improve them adaptive capacity to drought. Nowadays, special emphasis is put on the notion of adaptive capacity instead of vulnerability. So the need to have research in rural levels obvious, especially in Iran where there has not yet been any deep and encompassing study on the concept of adaptive capacity in rural level. adaptive capacity to climate change is the ability of a system or an individual to adjust to climate change or climate variability so as to minimize the potential damages or cope with the consequences. Therefore, adaptive capacity is the ability to plan and use adaptation measures to moderate the effect of climate change. There is an increasing need to develop indicators of adaptive capacity to determine the robustness of response strategies over time and to understand better the underlying processes.

Adaptive capacities of villagers depend on certain factors or attributes such as their knowledge on and number of times they use a particular adaptation strategy. Other factors are the availability and accessibility of the adaptation strategy. Also, the number of consultations that a villagers makes on a particular adaptation strategy affect whether the villagers will be lowly or moderately or highly adaptive to drought.

Identifying the overall level of adaptive capacity to drought in rural areas, in order to Effective management is special importance, Because that by identifying and ranking of adaptive capacity in rural areas, adopt appropriate management strategies to reduce the damage caused by drought is possible.

Therefore, the purpose of this study is assessing the adaptive capacity to drought of between four villages in the central part of the city Rawansar in Kermanshah province. For this purpose five most effective and important index to measure the  adaptive capacity to drought as follows:  Knowledge, Use, Availability , Accessibility and Consultation, according to the literature, were selected. Then by using one sample T-test, the effectiveness of each of the above-mentioned indicators on the villagers adaptive capacity were reviewed and approved from the point of view Village contributors of the central city Rawansar (N = 48) who were selected by census method. In the next step, to determine the index weight, using the snowball technique and purpose sampling, 10 experts in jahad  agricultural  office in Rawansar city were selected and their comments were used. The results by TOPSIS technique based on these indicators, showed that rural areas of Hasan Abad and Zalu Ab  in the Rawansar city, had the greatest adaptive capacity to drought, While  rural areas of Dawlat Abad and Badr had fewer adaptive capacity to drought. The Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS) is a multi-criteria decision analysis method, which  is based on the concept that the chosen alternative should have the shortest geometric distance from the positive ideal solution (PIS)and the longest geometric distance from the negative ideal solution (NIS).It is a method of compensatory aggregation that compares a set of alternatives by identifying weights for each criterion, normalising scores for each criterion and calculating the geometric distance between each alternative and the ideal alternative, which is the best score in each criterion.The findings of this study could have recommendations for rural planners to effective crisis management in order to reduce vulnerability and enhance resilience villagers to drought.


S. Reza Alvankar, Farzane Nazari, Ebrahim Fattahi ,
Volume 3, Issue 2 (5-2016)
Abstract

Due to the growth of industries and factories, deforestation and other environmental degradation as well as greenhouse gases have been increasing on the Earth's surface in recent decades. This increase disturbs the climate of the Earth and is called climate change. An Increase in greenhouse gases in the future could exacerbate the climate change phenomenon and have several negative consequences on different systems, including water resources, agriculture, environment, health and industry. On the other hand to evaluate the destructive effects of climate change on different systems, it is necessary to initially study the area affected by climate change phenomena. One of the most important effects of climate change on water resource is Drought.  On the other hand, one of the most serious consequences of climate change is how it will affect droughts and water resources.

Drought along with warmer temperature and less precipitation will threaten the water supplies for the crop irrigation, which will directly reduce the production of crops.The climate of the 21st century will very likely be quite different from the climate we observed in the past. The changes will continue to be large in the future period with increasing carbon dioxide emissions. Analyzing and quantifying the signal of climate change will be much in demand considering the above sectors, which are highly relating to the sustainability and human living.

In the past several decades, global climate models have been used to estimate future projections of precipitation [Intergovernmental Panel on Climate Change (IPCC), 2007], and have led to future estimation of drought, to quantify the impact of climate change and comparing the duration  and intensity of droughts under future climate conditions with current climate by using Atmospheric-Ocean General Circulation Models AOGCMs to predict future Precipitation. Global circulation models namely, coupled Atmosphere-Ocean Global Climate Models (AOGCMs) are current state of the art in climate change research. in This study aims at investigating the impact of climate change on droughts conditions in Iran using the Standard Precipitation Index (SPI).

The precipitation time series have been used for the estimation of Standardized Precipitation Index

(SPI) for three timescales, 3, 12 and 24 months, for the region. The outputs of HadCM3-A2 and A1B were applied for the assessment of climate change impact on droughts. One of the major problems in using the output of AOGCMs , is their low degree of resolution compared to the study area so to make them appropriate for use, downscaling methods are required. In this study we have used lars WG for downscaling monthly average of rainfall of AOGCM-HadCM3, and The HadCM3 outputs were downscaled statistically to the study area for a future period 2011-2040.then, was evaluated by the coefficient of determination (R2) between observed and downscaled data.  A method has been used for the estimation of annual cumulative drought severity-time scale-frequency curves. According to the rainfall results, in the 2011- 2040 period rainfall would decrease  to compared to baseline period in the study area.

The SPI time series were estimated (2011-2040) and compared with the respective time series of the historical period 1961-1990. Results revealed that there are decreases in the frequency of severe and mild droughts for the three examined SPI time series while there are increases in the duration of moderate droughts. This implies that droughts will be a concern in the future during the growing season (for the dominant crop) which should be considered in water resources management. specially in the west station of Iran.

Also, these frequency ratios were mapped by GIS on study area. Results showed that generally in the future periods, frequency of droughts ratio of three months drought time- scale will be increase in the North, North West and some parts of the south Alborz mountains and, The Ratio of long ( 24 months) drought for scenario A2 compare to the current climate shows increasing drought in the parts of the North khorasn, sistan and baluchestan and kerman provinces and parts of South West of Iran. scenario A1B shows increasing drought in the parts of the East of Mazandaran , Tehran , Horozgan and parts of Fars and Yazd  provinces.

Finally ,further  more analysis of drought, AWCDS-Timescale-Return Periods computed. These curves integrate the drought severity and frequency for various types of drought. The AWCDS time series were estimated

for basic period and 2011-2040 under scenarios A2 and A1B. The comparison indicated the three types of drought intensity increases for the three examined SPI time series in the South East of Iran.


Boromand Salahi, Mojtaba Faridpour,
Volume 3, Issue 3 (10-2016)
Abstract

Drought is the most important natural disaster, due to its widespread and comprehensive short and long term consequences. Several meteorological drought indices have been offered to determine the features. These indices are generally calculated based on one or more climatic elements. Due to ease of calculation and use of available precipitation data, SPI index usually was calculated for any desired time scale and it’s known as one of the most appropriate indices for drought analysis, especially analysis of location. In connection time changes, most studies were largely based on an analysis of trends and changes in environment but today special attention is to the variability and spatial autocorrelation. In this study we tried to analyze drought zones in the North West of Iran, using the approach spatial analysis functions of spatial statistics and detecting spatial autocorrelation relationship, due to repeated droughts in North West of Iran and the involvement of this area in the natural disaster.

In this study, the study area is North West of Iran which includes the provinces of Ardebil, West Azerbaijan and East Azerbaijan. In this study, the 20-year average total monthly precipitation data (1995-2014) was used for 23 stations in the North West of Iran. In this study, to study SPI drought index, the annual precipitation data of considered stations were used. According to the statistical gaps in some studied meteorological stations, first considered statistics were completed. The correlation between the stations and linear regression model were used to reconstruct the statistical errors. Stations annual precipitation data for each month, were entered into Excel file for the under consideration separately and then these files were entered into Minitab software environment and the correlation between them was obtained to rebuild the statistical gaps. Using SPI values drought and wet period’s region were identified and zoning drought was done using ordinary kriging interpolation method with a variogram Gaussian model with the lowest RMS error. Using appropriate variogram, cells with dimensions of 5×5km were extended to perform spatial analysis on the study area. With the establishment of spatial data in ARC GIS10.3 environment, Geostatistic Analyze redundant was used to Interpolation analysis Space and Global Moran's autocorrelation in GIS software and GeoDa was used to reveal the spatial relationships of variables.

The results showed that most studied stations are relatively well wet and this shows the accuracy of the results of the SPI index. Validation results of the various models revealed that Ordinary Kriging interpolation method with a variogram Gaussian model best explains the spatial distribution of drought in North West of Iran. So, using the above method the stations data interpolation related to SPI index in North West of Iran was done. The results showed that Moran index values for the analysis of results of standardized precipitation index (SPI) in all studied years, is more than 0.95. Since Moran’s obtained values are positive close to 1, it can be concluded that drought, in the North West of Iran during the statistical period has high spatial autocorrelation cluster pattern of 90, 95 and 99 percent. Results also showed that in all the years of study, Moran's global index is more than 0.95 percent. This type of distributed data suggests that spatial distribution patterns of drought in North West of Iran changes in multiple scales and distances from one distance to another and from scale to another and this result shows special space differences in different distances and scales in this region of the country. Results also showed that drought in North West of Iran in 2008 is composed of two parts: Moderate drought in parts of West and North West region (stations of Maku, Khoy, Salmas, Urmia, naghadeh, Mahabad and Piranshahr) and severe drought in the southeastern part of the study area (stations: Sarab, Khalkhal, Takab, Tabriz and Mianeh). So the pattern of cluster drought in the North West of Iran in 2008 is on the first and fourth quarter. The results of this index showed that drought and rain periods are similar in the studied stations. The results of the application of Moran's index about identifying spatial distribution of drought patterns showed that The values of the different years during the period,  have a positive a positive coefficient close to 1 (Moran's I> 0.959344) and this shows that the spatial distribution of drought is clustered. The results of the standard score Z values and the P-Value proved the clustering of spatial distribution of drought.

The results of the analysis of G public value, In order to ensure the existence of areas with clusters of high and low values showed that The stations of Maku, Khoy, Salmas, Urmia, naghadeh, Mahabad, Piranshahr and Parsabad follow the moderate drought pattern in the region and are significant at the 0.99 level. Jolfa station also has a mild drought of 0.95 percent confidence level and for Sardasht station is significant in 0.90 percent. High drought pattern in Sarab, Khalkhal, Takab, Tabriz and Mianeh stations was significant in 0.99 percent level and also for Ardabil, Sahand and Maragheh stations very high drought pattern was significant in 0.95 percent level and for Meshkinshahr and Ahar high drought pattern is significant in 0.90 percent. By detection of clusters of drought and rain in the North West of Iran using Moran’s spatial analysis technique and G general statistics a full recognition of the drought affected areas in this region can be obtained and take the necessary measures in its management 


Hassan Zolfaghari, Zahra Nori Samoleh,
Volume 3, Issue 3 (10-2016)
Abstract

Drought is one of the most important hazards that occur in all the earth especially in arid and semi-arid climates. Every year, about half of the earth’s surface experienced droughts and while drought is not a constant feature of any climate but occur more frequently in arid and semi-arid regions of the world. Although the occurrence of droughts cannot be prevented but by studying the nature and characteristics of droughts and also identify factors that affecting their occurrence useful information can be gained about drought and their destructive effects. The researches in recent years designed and proposed a lot of indices to study and analyze the droughts and today various characteristics such as intensity, duration, area and so on with these indices are studied. Many indices used by researches to analysis and identify properties of climatic droughts and dry periods. In these indices often the variables of precipitations, combination of precipitations and temperature, humidity or evaporation, crops yields and teleconnection climatic indices are used.

In this study using the CPEI index and 30 years (1980-2009) daily rainfall data in 40 synoptic stations overall Iran, to analysis and assess of Iran droughts suitable variables detected. Four seasons and annual period is considered in this study. To determine the appropriate variables in the design of suitable models and modeling of drought to assess and predict droughts Otun in 2005 proposed CPEI index as Conjunctive Precipitation Effectiveness Index. He selected 10 conjunctive precipitation variables as ORS(Onset of Rainy Season), CRS(Cessation of Rainy Season), LRS(Length of Rainy Season), TWD(The Total no of Wet Days), TDS(Total no of Dry Spell), TDW(Total no of Dry Days within a Wet Season), TDY(Total no of Dry Days within a Year), LDS(Length of the Dry Season), MDL(Maximum Dry Spell Length within a Wet Season), MAR(Mean Annual / Seasonal Rainfall Depth) and determined the relationships between variables in each synoptic stations and climatic regions. Since the units of measurement the rainfall variables are diverse, it is essential that the units be converted to a standard unit, in other words variables be standardized. The relationship between variables was determined by Pearson correlation coefficient. Finally, the right combination of precipitation variables for each station through the proposed formula Otun(2005) were determined. In the end, for each of the seasons and the annually period regionalization maps were prepared.

 All 40 synoptic stations were evaluated by Otun’s method (Aton, 2005). The results showed that 95 percent of stations in spring, 75 percent in fall, 57 percent in winter and 75 percent in annual period are compatible with used method. Thus, spring, fall and winter seasons and also annual period are compatible with above mentioned index. Among the used variables MAR, MDL, TDY and TDS which with respectively are as follows: total amount of precipitation in any period, the maximum duration of dry periods in a wet period, the total number of dry days in a wet period and the total number of dry period during wet period among the stations are more abundant. In annually period, in addition to the above mentioned variables, precipitation variable of LPS (length of dry period) also seen among some stations. Also, results showed that CPEI index can be used on most stations and climatic regions of Iran. It was also found that the spring compared the other seasons and annual period is more comparable on the base of CPEI index.   

  Otun in 2010 used the CPEI index in semi-arid region of Nigeria and has achieved good results. The results of our study show good agreement with Otun’s work. The use of this index in the study of meteorology, climatology, agriculture and many environmental projects can be beneficial because in many of these fields of study, precipitation and its characteristics have an important role. In general we can say that in regions where CPEI index does not show a high proportion or set of variables are not enough it is better to use other indices such as SPI and RAI. The results obtained in similar climate zones such as Nigeria has shown that CPEI index has very good ability to identify and explain the precipitation effectiveness variables which can be used in modeling of droughts and dry periods. There are many similarities between combination of precipitation variables that identified by CPEI index for Iran and other regions of the world. Similarities, especially with respect to MAR, MDL, TDY and TDS are abundant.


Said Balyani, Yones Khosravi, Alireza Abbasi Semnani,
Volume 3, Issue 4 (1-2017)
Abstract

Hazard is potential source of harm or a situation to create a damage. So identification of zones exposed to hazards is necessary for planning or land use planning. But this situation becomes more critical when they appear at the population centers. So applying the principle of passive defense based on environmental capabilities is unarmed action that caused the reduction of human resources vulnerability, buildings, equipment, documents and arteries of the country against the crisis by natural factors such as drought, flood, earthquake, etc. Considering the possible occurrence of such risks in population centers, ready to deal with what is known unpleasant and undesirable consequences is necessary. On this basis and given the importance of population centers in Helle and Mond basins, in this study, the authors tried to analyze the Rain hazards of drought and flood.

The study area,Helle and Mond basins, with about 21,274, 47653 km2 area, respectively are located in the south of Iran. The Helle basin approximately is between 28° 20'N and 30° 10'N latitudes and between 50° E and 52° 20'E longitudes and Mond basin is between 27° 20' and 29° 55' latitudes and between 51° 15' and 30° 27'E longitudes.These basins are located in sides of a massive sources of moisture, Persian Gulf.

In this study, data from 23meteorological and synoptic stationsstations, during aperiod of20 years (1992-2011)in northern region of the Persian Gulf (Mond and helle basins)were used to calculate Standardized Precipitation Index (SPI). The data were collected by the Iranian Meteorological data website (http://www.weather.ir). The SPI is primarily a tool for defining and monitoring drought events. This index may be computed with different time steps (e.g. 1 month, 3months, 24 months). The SPI is defined for each of the above time scales as the difference between monthly precipitation (xi) and the mean value ( ), divided by the standard deviation. To assess flood risk zones, the flood, annual evapotranspiration, cities and populations centers layers were collected in Helle and Mond basins position. The annual precipitations and the SPI maps were drawn by Geostatistics, Kriging. It also the flood and annual evapotranspiration layers were weighted by Euclidian distance method, separately. Finally, all layers are weighted by AHP and fuzzy-linear methods (descending and ascending linear function) into vulnerable layers. The final map of vulnerable areas with flood and drought high risk was drawn based on the algorithm of linear-Fuzzy in a raster format.

According to the results, eastern, north eastern and south eastern part of Mond basin had high annual precipitation. Based on this result, it said that these parts of study area were known the least dangerous areas of vulnerability. The results also showed that with passing of the western regions and going to the center of the study area the annual rainfall have been added over the years. Kazeron, Chenar Shahijan, Firouz Abad, Borm plains and some parts of Khane Zenyan and Dash Arzhan are cities located in this regions. Low latitude, Proximity to the warm waters of the Persian Gulf, low annual precipitation and high temperature causing evaporation and inappropriate environmental conditions in Boushehr province and some coastal cities such as Genaveh, Deilam, Boushehr, Baghan, Lar and Khonj. Accordingly, west, north west, south and south west regions in Helle basin were located in extreme vulnerability zone with a loss of annual rainfall for drinking and agricultural production and poor nutrition underground aquifers.


Vakil Heidari-Sareban, Ali Majnouni-Toutakhaneh,
Volume 3, Issue 4 (1-2017)
Abstract

Nowadays, the severity of the drought hazard has reached a point that has affected all the rural and urban areas surrounding it. Increasing the resilience of villages via livelihood solutions, is one of the best strategies for reducing the vulnerability of villages against natural hazards such as drought. The eastern side of the Lake Urmia consists of the six cities of Osku, Azarshahr, Bonab, Shabestar, Ajabshir and Malekan. Totally, there are 199 villages in this region, which are affected by the drought of the Lake, directly and indirectly and according to the statistics, the quantitative and qualitative reduction in agricultural and livestock productions and soil quality, the incidence of respiratory diseases and … have risen sharply compared to the past and a number of villages have been evacuated. Also because of the lack of a coherent strategy, which should be taken by the planners and authorities, the important measures to revitalize the Lake has not been taken yet and the dimensions of the threat are increasing day by day.

Current study investigate the factors affecting the resilience of rural settlements of the eastern side of the Lake Urmia against Drought. This is an applied and analytic-explanatory research. The data is collected by questionnaire from the villagers living in rural areas of the six cities, which are the statistical population of the research and the total number of the villages estimated 199 with 232295 persons.

The standardized Perception Index (SPI) is used to estimate the varying degrees of the villages in the eastern side of the Lake Urmia. In the next step, the possession index for each of the villages was calculated and the studied villages were classified based on it. On this basis and by considering the four status of drought and the three levels of possession, after sorting the villages on the basis of these two indexes, 43 villages were chosen from different regions of the eastern side of the Lake as the first level of analysis, using systematic random selection. Also, to classify the villages in the regard of possessing of the development facilities, the composite indicators called Morris pattern and 47 existing items are used, which are calculated in 9 different indexes. Finally, the obtained information were analyzed using SPSS and GIS software.

Regarding to the research findings at the eastern side of the Lake and on the basis of Standardized Precipitation Index (SPI), about 78% of this area has been experiencing drought. Also, the status of the overall indicators of household's livelihood capital on the basis of the Normal Scale from 0 to 10 is 3.34, which shows the unfavorable status of this index. The results of the study in the field of the level of civil and institutional development showed that on the basis of the Normal scale from 0 to 10, civil development is 4.86 and institutional development is 3.69. Lastly, the research findings for the three levels of the sustainable development of the livelihood shows that the livelihood diversification is 3.61, in depth agriculture 3.24 and migration strategy is 3.02. The analysis of the results of the sustainable livelihood shows that the decrease of drought of the villages increases the diversity of the livelihood of the villagers. According to the results obtained, the mean of the resilience index of the investigated households on the basis of 0 to 10 equals to 4.86, which is close to the average level. The classified distribution of the resilience level and the focus of the more than of 56% of the households with average level of resilience confirms this situation. 30.26% of the households has low resilience and 15.64% has high resilience in the face of existing conditions. Upon this basis, the highest amount of the resilience equals to 5.38, which exists in the villages with severe drought conditions and by decrease of the drought, the resilience of household’s decreases. Finally it can be said that the villages with a long history of vulnerability from drought and also having more intense droughts, has a higher resilience level in dealing with the situation.

According to the results, the highest amount of vulnerability exists in the villages with low experience in dealing with the long-term conditions of drought, which their economic and social structures are not prepared to deal with the conditions. While the average amount of the livelihood capitals and the resilience of the studied statistical population do not show an appropriate conditions, but totally, the results and relationships of the studied variables conforms the role of possessing all dimensions of livelihood capital on taking appropriate approach to dealing with the conditions of drought in the Lake Urmia. In the field of taking the approaches of diversifying the livelihood resources of the villagers, there are several scientific and examined solutions, such as considering the education and awareness as a definite reality, also the knowledge and skills of the villagers in the fields of modifying the crop patterns, water saving strategies, the use of efficient products and making use of the other high-income jobs must be increased.

In the field of educational solutions, besides providing modern knowledge and international successful experiences, it must be possible to make use of the indigenous knowledge and experiences of the villagers.


Batol Zynali, Sayyad Asghari Saraskanroud, Vahid Saffarian Zangir,
Volume 4, Issue 1 (4-2017)
Abstract

Drought is a concept that is generally understood on a basic level, but is difficult to quantify. Palmer defined a drought as a meteorological phenomenon that is characterized by ‘‘prolonged and abnormal moisture deficiency. A drought can alternatively be broadly defined as a temporary, recurring reduction in the precipitation in an area.

Aridity and drought are not synonymous. Aridity is a measure of long-term average climatic conditions. Both humid and arid regions experience droughts. However, the inter-year variation in precipitation is greater in arid regions and there is a greater probability of below average precipitation in any particular year. Arid regions are thus more prone to droughts and may experience more severe impacts from droughts.

In this research was used temperature and precipitation monthly data of Urmia, Tabriz, saghez, Maragheh, and Mahabad station in statistically period 1985-2014. Run test was used to study the homogeneity of data. Randomness and homogeneity of data was approved.at a confidence level of %95. SEPI Index and ANFIS model was used for determining and forecasting drought in Urmia lake basin. SEPI index is more complete than SPI. Results of SEPI were used in ANFIS model.

Fuzzy index SEPI[1]: Standardized precipitation index and evapotranspiration (SEPI) to address some of the disadvantages of SPI index is provided. Evapotranspiration and precipitation index SPI index and SEI standardized integration is achieved. The index is the result of drought monitoring phase of architectural models using fuzzy logic in a fuzzy inference system is designed. How to design this model and determine SEPI is described below.

Fuzzy architecture drought monitoring: for derivatization indices SPI and SEI using Fuzzy Inference System, Due to the structure of fuzzy models were considered.

SPI index[2]: Standardized Precipitation Index is an indicator widely used in Drought Monitoring. This index is one of the few indicators drought monitoring and could even say the only indicator that the time scale is considered. Depending on the time scale to determine the effect of different sources of agricultural drought, hydrological and so determined. Time scale can be determined from one month to several years. SPI index is used to calculate the only element rainy climate. Monthly precipitation amounts for each station in the desired time scale is calculated.

SEI index[3]: Since the index SPI Single Entry, rain, The SPI index values under the influence of changes in temperature and evapotranspiration parameter that is powerful factor in the drought, it will not be. So to enter the effect of temperature and evapotranspiration in SPI, SEI (evapotranspiration index Standard) To calculate this index, before any measures should reference evapotranspiration for the period to be estimated.

define the rules for combining indicators SPI and SEI: Different classes index SPI and SEI rules or the same combination of conditional statements in the form if, as a class of SEPI index in the lead, is defined. This rule only a combination of different modes SPI and SEI indices that lead to SEPI index shows. In this regard, the rules can be combined to fit different for successive written and stored in the knowledge base. Since the output of the resultant composition, indices SPI and SEI are involved in determining the status of SEPI, Weight each of the indicators with regard to the effect of precipitation and temperature parameters on the severity of the drought was considered As a result, SPI indices and weights 0.667  and 0.333, respectively SEI were included in the calculations.

According to the results, according to the research, education Anfis model with 75 percent of the data series is well done SEPI and much has been done to ensure education is nearly 100 percent. So that the graphic maximum of 0.26 percent error in saghez station on a scale of 6 months and the lowest average error of 0.10 percent in Urmia station is on a scale of 6 months. In modeling, validation data, the average error modeling is naturally higher than the average training error. Most average forecast error saghez on a scale of 6 months at the station 0.34 percent and 0.10 percent, the lowest on a scale of Urmia station is 6 months. But the coding maximum of 0.65 percent error in saghez station on a scale of 6 months and the lowest average error of 0.32 percent in Tabriz station is on a scale of 6 months. SEPI index in the time scale of 6 and 12 months is used for investigate the characteristics  of adaptive neuro-fuzzy inference system in order to drought and drought forecasting model. According to the findings in this study, the frequency of drought in the stations of Urmia and Saghez and Maragheh on a scale of 6 months is more than the scale of 12 months in the basin of Lake Urmia but in Tabriz and Mahabad Stations situation is the vice versa. The drought in Urmia Lake basin is increasing trend but temperature has increasing trend with more intensity. The highest and lowest percentage of drought was seen in Urmia and Mahabad station respectively. The results of the forecasting of index by ANFIS model showed that the most training error is in Tabriz station (0.51) and the lowest training error is in Maragheh station (0.36) in a scale of 12 months in coding. In validation data modeling the average of modeling error is higher than the average training error naturally. According to the definition of drought SEPI was presented based on amounts of 0.73 or higher or mild drought to higher floors as dry conditions arise The scale of 6 months in Urmia station with 13.14 percent to 10.89 percent saghez station, Tabriz stations with 5.58 percent, with a 5.1% Mahabad station and Maragheh with the amount of 4.82 percent, the drought has occurred. The time scale of 12 months in Tabriz station by 9%, saghez station with 7.26 percent, with 6.11 percent of Urmia station, Maragheh with 5.5% and the amount of Mahabad stations with a 3.44 percent, from months of study in the series, drought has occurred.

Results of SPEI are:

  1. Drought trend is increasing in urmia lake basin. Temperature has increasing trend extremely.
  2. The highest percentage of drought is in Urmia station and its lowest is in Mahabad station.
  3. Percent of frequency of drought in Urmia station, Saghez and Maragheh on a scale of 6 months is more than to 12 months, but the scale of Tabriz and Mahabad stations with the photos. Stations Tabriz and Mahabad is in the opposite situation.

Results of ANFIS Model are:

In study area and in ANFIS model whatever forecasting coming years is shorter; confidence of forecasting will be more.

Due to the errors amount obtained in model validation, in study area forecasting of drought by ANFIS model was done with confidence 94%.


[1] - The combination of indices SPI (Standardized Precipitation Index) and SEI (evapotranspiration index standard) based on the rules of the Fuzzy Inference System.

[2] - Standardized Precipitation Index

[3] - Standardized Evapotranspiration


Saeid Hamzeh, Zahra Farahani, Shahriar Mahdavi, Omid Chatrobgoun, Mehdi Gholamnia,
Volume 4, Issue 3 (9-2017)
Abstract

As a result of climate change and reduction in rainfall during the last decade, drought has become big problem in the world, especially in arid and semi-arid areas such as Iran. Therefore drought monitoring and management is great of important. In contrast with the traditional methods which are based on the ground stations measurements and meteorological drought monitoring, using the remote sensing techniques and satellite imagery have become a useful tool for spatio-temporal monitoring of agricultural drought. But using of this technique and its results still need to be evaluated and calibrated for different areas.
The aim of this survey is to study the spatial and temporal patterns of drought using remote sensing and the regional meteorological data in the Markazi province. For this purpose, the MODIS satellite data between the years of 2000-2013 have been used to monitor and derived vegetation indices. Drought indices based on satellite data including the Normalized Difference Vegetation Index (NDVI), Vegetation Condition Index (VCI), Temperature Condition Index (TCI), Temperature Vegetation Dryness Index (TVDI), and Soil Water Index (SWI) were obtained from the MODIS satellite data for the period of study for different temporal scales (seasonal, biannual and annul).Then, correlation between obtained results from satellite data and standardized precipitation index (SPI) have been analyzed in all time periods.
Results show that study area has a low to medium vegetation cover. According to the results, the climate situation of the study area is more compatible with the seasonal results of the VCI, and VCI was selected as the best indicator for agricultural drought monitoring in the study are. The obtained results from the applying of VCI over the area show the drought condition in 2000 and 2008 and the wetness in 2009 and 2010 during the study period.

, , , ,
Volume 4, Issue 4 (1-2018)
Abstract

Farmers in developing countries are among the most vulnerable to climate change effects, particularly drought. Drought is a serious and dangerous phenomenon in most part of the world particularly arid and semi aired region such as Iran and it is estimated that Middle East is expected to be particularly badly affected with a decline in precipitation of at least 40mm over the coming century. In Sum, drought is a recurring climatic event that can happen in all parts of the world. In terms of people affected, it is the number one risk of all natural hazards, with more than 1 billion people affected in the last decade. In fact, drought is considered as a disaster, causing heavy costs for farmers' livelihoods and agricultural systems. Therefore, most of the drought effects are in societies where agriculture is a major component of their economic activity. As such, the livelihoods of farmers that are among vulnerable communities is strongly affected. In other words, at the global scale, agriculture is by far the most important user of water and, as pressure on water resources increases, the need for new approaches to managing those resources is becoming more pressing. However strong evidences confirmed that farmers can actively response to drought and manage and reduce it effects. As such promoting farmers to actively response to drought is very urgent and necessary. First step to this policy is understanding farmers’ current situation and their intention and behaviour. In fact, understanding farmers’ perception toward drought is a key to preparing to reduce the effects of it. In other words, drought management relies heavily on farmers understanding how to reduce their water consumption and on applying their understanding to everyday activities so that they consume sustainably. Furthermore, attitudes of farmers toward drought and drought management are closely linked with their behavioral management and experience with past events (Yazdanpanah et al., 2013). Hence, attitude and past experience can affect the assessment of coping strategies in the future, which is especially important from a preventive action point of view (see Krömker and Mosler 2002).  Therefore, a deep and proper understanding of the factors that determine adaptation with the new conditions is very much needed. As such, the aim of this study is to investigating farmers’ intention and behaviour toward drought management. Among other dimensions it is assumed that psychological issues play an important role in predicting farmers’ intentions and actual responses, however, little research has focused on the psychological mechanisms that facilitate or constrain drought adaptation behavior. In this context, a study was carried out to identify the most prominent drivers of, and impediments to, drought adaptation, using health belief model. The Health Belief Model is an expectancy value model. According to this theory, an individual’s behavior is a utility of the probability of consequences accompanying with that behavior and the probable value or evaluation of those consequences. The overall desirability of the behavior is based on the summed products of the expectancy and value of consequences. Theory claims that health decisions are based on two major components. These are perception of threats and behavioral evaluation, which, in turn, is divided into four psychosocial sub-components (beliefs) the “threat perception” refers to a supposed vulnerability to a disease and estimated costs of this disease, while “behavioral evaluation” refers to benefits and barriers for adopting own behavior. Also based on these four beliefs, the HBM comprises other additional cognitive or motivational components to change or predict behavior, such as “cue to action” and “health motivation” or “general concern”. These components refer to the cause of health behavior, which, in turn, impacts the level of worry about health problems. Furthermore, Becker and Rosenstock (1987) added “perceived self-efficacy” as a perceived behavior control component to the HBM. While perceived self-efficacy originates from the social cognitive theory and refers to the degree, to which following a particular pattern of behavior is imaginable or unmanageable for the person and can enhance the predicted power of the model. The Health Belief Model was quantitatively tested using the survey methodology to understand farmers’ intention and behaviour. An in-depth literature review was used to develop the questionnaire to collect data for this study. Data were collected through personal interviews based on a structured questionnaire. The questionnaire was structured to assess the central components of the Health Belief Model. The questionnaire was used for a face-to-face survey with farmers. Answering time for the questionnaire was about 15-20 min. Researchers received all completed questionnaires directly after the survey; no intermediaries were involved into the analysis or interpretation of results. The questions were scored on a 1-5 point scale (very low, low, moderate, high, very high) to reduce the statistical problem of extreme skewness. Based on Ajzen's (1985) recommendations, scales containing multiple items were developed to measure each of the psycho-social variables. It is important to note that for assessed Health Belief Model variables we used items that closely follow the measurement of this constructs used in past studies. The statistical population of this study was the farmers of Dehloran city, located in the villages of Anaran, Seyyed Ebrahim, Seyyed Naseroddin, Abu Ghavir, Dasht-e-Abbas, Nahr Anbar. In order to determine the volume of the sample, the Kargets and Morgan tables (1970) were used. According to the size of the population (farmers in Dehloran city), the sample size was 320. In this study, a randomized cluster sampling method with proportional allocation was used. The reliability of the main scales of the questionnaires’ was examined by Cronbach Alpha coefficients, which ranged from 0.65 to 0.84, indicating the tool of study is reliable. A multiple step-wise regression analysis, with intention regarding response to drought as the variable, and with Health Belief Model variables as the framework, the results revealed that general beliefs, self-efficacy and perceived benefits are significant predictors. These three variables predicted 54% of the variance in intention regarding response to drought. Same regression was carried out so to determine factors that can predict farmers’ behaviour regarding drought management. The results revealed that intention, perceived severity, perceived vulnerability and perceived benefits are significant predictors of behaviour. These variables predicted 21% of the variance farmers’ behaviour toward drought management.

Dr Bromand Salahi, Dr Majid Rezaei Banafsheh Daragh, Dr Abdolreza Vaezi, Mr Mojtaba Faridpour,
Volume 4, Issue 4 (1-2018)
Abstract

Drought is a natural occurrence that occurs repeatedly or alternately and is likely to occur in almost every kind of climatic event. Also, the distinction between this phenomenon and other natural disasters is that unlike other disasters, this phenomenon gradually over a relatively long period of time to act and its effects may be delayed after a few years and more than any other natural disaster appears. Several indicators have been presented to decide the characteristics of hydrological and meteorological drought. These indicators are generally based on one or more climatic elements. The SPI and SWI indicators are similar in terms of ease in calculations and results, and use monthly precipitation data and monthly spatial data rates. The simultaneous effect of meteorological droughts on groundwater levels rarely happens. Therefore, the present study investigates the effect of meteorological droughts on the groundwater level of Marand plain and calculates the time delay of drought on groundwater level.
The study area in this study is Marand Plain in East Azarbaijan Province. In this research, we used meteorological data (average monthly rainfall) of 7 rain gauge stations during the statistical period (1980-2012), and the monthly water level data of 23 piezometric wells during the statistical period (2001-2011). The correlation between stations and piezometric wells and linear regression method was used to reconstruct the statistical defects, then SPI and SWI indices were used to study the rainfall and groundwater changes process and the analysis of drought conditions in the meteorological and underground watersheds. The SPI index is basically calculated for periods of 3, 6, 9, 12, 18, 24, and 48 months. Also, the standardized water level indicator (SWI) has been used as a criterion for assessing occur drought and wet years in the Marand plain. The purpose of the SWI index is to allow zoning of groundwater level fluctuations at the study area. Extraction of drought and wet year intensities in different scales and basin zonation for drought maps in Marand plain was first calculated by entering the monthly values in DIP software, SPI values for 12-month time series. SWI values were calculated from monthly data of piezometric stationary level surfaces, such as SPI values, with the help of DIP, Minitab and Excel software. Geostatistical Analyst was also used to decide the weather drought and groundwater drought periods for the ArcGIS software.
 
 
The results of the SPI values showed that meteorological drought is not of a definite local place, while groundwater droughts have not occurred randomly in the area and its concentration in the west of the aquifer is more than the east. Considering the increase in the area under cultivation, to compensate for the water needs of agricultural lands, an increase in the harvesting of underground water table has occurred in order to compensate for the need for water, indicating a tangible relationship between the rainfall and the level fluctuation in the Marand plain. Therefore, considering the increase in the area under cultivation during the years of drought in the region, the best correlation between them was -0.720 with a delay of 5 months, in order to investigate the effects of drought on the surface of the station, which was significant at 1% level It illustrates the impact of groundwater resources with a 5-month delay. Also, the results of the survey of monthly data of Marand plain surface during the statistical period (2001-2011) showed that the groundwater level of the plain had a negative trend that fell by about 2 meters.
The SPI and SWI indices make it possible to calculate the start and end times of meteorological and groundwater droughts in a steady period of information computed by these indicators, as well as the severity, duration and frequency of droughts. Drought zoning maps using SPI and SWI values in the Arc Gis environment showed that meteorological droughts, due to the characteristics of droughts, do not have a definite spatial location, while droughts Underground water does not occur accidentally in the area and their concentration has been created at specific points in the aquifer, which have tropical and human stresses (in terms of excessive and permissible withdrawal). Although the weather factor has had the greatest impact on the level of stagnation in the Marand Plain in recent years, this crisis is the result of a set of factors, including free radicals, which is itself due to meteorological droughts; therefore, due to the trend of change The level of the stand is consistent with drought changes, it can be concluded that the drop in the surface of the Marand Plain is mainly affected by drought. According to the results of this study, it seems that continuous monitoring of drought situation and strong monitoring of harvesting, especially in severe and prolonged droughts, is very necessary to prevent a significant drop in groundwater level in the Marand plain

Dr Moslem Savari, , , ,
Volume 6, Issue 2 (9-2019)
Abstract

Modeling Drought Effects on Sustainable Livelihoods of Small Scale Farmers in Rural Settlements of Kurdistan Province
1. Assistant Professor, Department of Agricultural Extension and Education, Khuzestan Agricultural Sciences and Natural Resources University
2. Professor at Department of Agricultural Management and Development at University of Tehran
3. Professor at Department of Agricultural Management and Development at University of Tehran
4. Professor at Department of Agricultural Management and Development at University of Tehran
 
Vulnerability and adaptation to climate change are local and context-specific, though connected to complex processes at multiple temporal and spatial scales. As such, there is a growing awareness that place-based studies of current and past responses to climatic stress can shed light on the capacity of a given system to respond to future climate change. There is also a growing appreciation of the importance of institutions—formal and informal—in shaping adaptation strategies and mediating the adaptive capacity of households and communities. While rural resource-dependent communities have historically coped with climatic fluctuations, whether such coping mechanisms are still successful today, and will be in the future, depends on the structure of supporting institutions and the way in which they mediate access to entitlements.  Indeed, most social–ecological systems have undergone dramatic change in the last century due to climatic, landscape, and institutional shifts. Because coping mechanisms are developed in relation to particular landscapes, livelihoods, and institutions, social and ecological changes have altered relations across these elements, impacting the effectiveness of particular coping strategies. For instance, pastoralists have historically deployed a suite of coping mechanisms in response to the highly variable climate of semi-arid and arid landscapes. Yet, these capacities may be increasingly compromised in the rangelands of East Africa due to increasing exposure to climate extremes, such as flood and drought and shifting institutional environments. The mechanisms that pastoralists in East Africa historically utilized to cope with climate variability were part of a tightly coupled system where livelihoods, institutions, and landscapes were mutually reinforcing. Pastoralists’ livelihoods were co-produced with a savanna mosaic landscape managed as a common property system by formal and informal customary institutions.
Farmers frequently cope with risks due to the uncertainty of climatic conditions .Population growth,  changes in agricultural policies, environmental regulations and the degradation of natural resources such as soil and water also present farmers with numerous challenges. Although farmers have experience in coping with a certain degree of uncertainty, increased climate variability and changes may cause severe problems. Drought in particular is a climatic disaster that creates substantial costs for farmers and affects their agricultural systems extensively. Drought is the most complex of all natural hazards . making the arid and semi-arid regions of the world vulnerable. Although drought has not been well documented ,  the resource-dependent sectors such as agriculture are the most vulnerable to the impact of this phenomenon. A review of the long-term annual precipitation trends indicated that drought had a worldwide return frequency of every 20e30 years .  However, in the last 50 years, some countries such as Iran and Bangladesh have experienced approximately 27 and 19  drought events, respectively. Therefore, for arid and semiarid regions, drought is a recurrent feature that could lead to the loss of crop production, food shortages and starvation  if not managed appropriately. According todrought impacts could be managed at macro (national), mesa (local) and micro (village and household) levels. However, the micro-level management (i.e., what the farmers do in response to drought) is of great importance. A review of the studies of farmers’ decision-making in response to climate variability revealed that most research has focused on the decision event and not on the entire process.
The main Purpose of this study was to modeling drought effects drought effects on sustainable livelihoods of small scale farmers in rural settlements. Statistical population of this study consisted of all Small-Scale Farming in Kurdistan province. Using Kerjcie & Morgan sampling table, 402 person were selected as the sample using stratified proportional sampling method. The instrument of the study was a questionnaire which its validity was confirmed by a Content validity and construct validity and its reliability was established by calculating Chronbach's Alpha and Combined reliability Coefficient (α>0.7). 
The results of Man- Kendall test showed that the level of aquatic and dry crops, along with the amount of crop production, has increased over time but there is no statistically significant effect on dry production. Also, the results showed that in the economic aspect, the greatest impact on distribution of income and living expenses, in the social dimension, on location affiliation and security and social welfare, the environmental dimension has had an impact on environmental pollution and land resources and on institutional aspects more on the cooperation and participation of the people.
In addition, the results of structural equation modeling showed that drought had the most impact on sustainability livelihood dimensions, respectively, on social, environmental, economic and institutional dimensions.
Keywords
Sustainable livelihood, drought, small scale farmers, rural settlements, Kurdistan province
 
 
 
Dr Hamid Ghorbani, Dr Abbas Ali Vali, Mr Hadi Zarepour,
Volume 6, Issue 2 (9-2019)
Abstract

Drought is one of the most complex and unknown natural phenomena that causes a periodic water crisis in the affected areas. Increasing water demand on the one hand and the experience of droughts in the province in recent years have led to the water crisis. Knowing the drought is one of the requirements for water crisis management. The purpose of this study was to analyze the trend of the SPI drought index in Isfahan province using nonparametric Sen’s slope test, Pettitt’s change point test and Man-Kendall test. From the monthly climatic data of 10 synoptic stations with a length of 27 years (1990-2017) for time series    The results of applying  Mann–Kendall  and  Sen’s slope tests based on SPI Index for  9, 12, 18, 24 and 48 month time periods, shows drought trend is significantly increasing for all stations out of Ardestan, Esfahan and  Shahreza  stations. In Ardestan station, the drought trend is significantly decreasing for 9, 12, 18, 24 and 48   month time periods and in Isahan station, the drought trend is significantly decreasing for only 48 month time period, and in Shahreza statition, the drought trend is significantly increasingonly for only 18 month time period.
  Despite all stations, the drought trend for one month time period, is significantly increasing just  for Naein station.
   In addition, applying Mann–Kendall test  on monthly rainfall for all station  shows downward but  not significant trend.
   Finally, applying Pettitt’s change point test based on SPI  Index  for 9, 12, 18, 24 and 48   month time periods indicates  the existence of a  significant change point. For same periods we observe  no change point for the monthly rainfall  in all stations.
   In summation, considering the SPI drought index, about 59% of  all stations show significant downward trend bases on Mann-Kendall test and 60% of  all stations show significant slope  based on Sen's slope test and 75% of  all stations show significant change point based on Pettitt's test. In general, for drought analysis using different time periods for the SPI index, in a short time period. (such as 6 months) drought is more frequent but shorter, and as the period increases the duration of drought also increases but frequency decreases. All together, we are facing  a water crisis in Isfahan province and  we must manage water demand  very urgently.
Reza Doostan,
Volume 6, Issue 4 (2-2020)
Abstract

An Analysis of Drought Researches in Iran
Extended Abstract:
  Iran is located the spatial geographical position in the south of the temperate region and north of the tropical region between the northern latitudes 40 to 25 degrees north and 65-44 degrees eastern along the seas, oceans and warm and great desert, on the other hand, with complex topography in the Alpine- Himalayas mountain belt (the world's largest mountain belt). These conditions have caused the climate of Iran to experience a variety of the prevailing natural hazards (33 of 43 world-wide risks). One of the natural hazards is the drought that happens over the Iranian plateau since the distant past, with the name of Dave of Drought, and so far. The Iranian plateau has undergone various drought periods over the past decades and various civilizations have faced this risk, and some of the Iranian ingenuity and management have emerged about this risk of the Iran. These include qanats, reservoirs built on commuter routes and cities, historical gardens, and so on. Today, this risk is dominant over the Plateau of Iran every year, and with increasing population and growth in different sectors and, in some cases to mismanagement, followed by a larger crisis called the water crisis and the crisis Economic-social, immigration, and so on. So, given the importance of the subject, different researchers have studied different aspects of this hazard. The fact is that in the past few decades, with the advent of computers and software and data, research has become easier and more scientific, naturally, in Iran, with these tools and data, researchers has been done on different parts of the crisis. What was the achievement of these studies, and most importantly, did the researchers contemplate a practical solution to the crisis on the Iranian plateau? This study provides an overview of past studies of drought and their achievements over the last few years.
In this study, used Four hundred and three of scientific articles were published in various journals to termed "drought" in the article titled of scientific information database (SID), one of the most important sources of internal research in Iran. The distribution of the time of research and distribution of various scientific fields that investigated the drought was identified. By studying the articles and the results from them, we found that 384 scientific articles with a specific output. Based on these findings, the frequency of articles in different fields of study was determined and analyzed.
researches of drought in the past years (1379 to 1391) had increasing trend and since 1394 has been decreas in Iran. The most drought research has been done in agricultural sciences with 166 papers from 403 papers (41.2%), geographic sciences with 118 papers (29.3%) and Medical and basic sciences and engineering sciences have the least research, 0.2, 2 and 5% respectively. 78% of the studies have examined the drought in different parts of Iran And 11 percent of the articles  evaluated the consequences of this  phenomenon. 7% of drought studies have predicted this phenomenon with different statistical models and 2.5% and 2% are dedicated to drought management and zoning  in different regions of Iran respectively. Most drought studies hase been in Iran, Khorasan, Fars, Sistan and Baluchestan, Tehran, Isfahan and Kermanshah, but in other parts of Iran, studies have also been conducted in different regions. Therefore, the drought phenomenon has been studied in all regions of Iran and drought assessments have been carried out.
The reduction of drought researches in recent years suggests that quantitative and qualitative research has been carried out in this basin before 1395, and drought has been studied and evaluated with different indicators in different regions of Iran. The reality of Iran's climate and research shows that every part of Iran experiences a drought phenomenon, which is an Inherent characteristic of the climate of Iran, that given the geographical location and atmospheric patterns affecting these latitudes on the planet. The consequences of drought have also been reflected in different parts of the environment, social, economic, and so on. As part of the newspapers has indicative of the damage to this climatic phenomenon in recent years. It seems that the dominant section of the phenomenon is associated with the unconscious and real perception of managers and people of this phenomenon (which has a cultural root). At present, the consequence of severe and droughts in recent decades is the lack of proper planning and environmental degradation and crisis in various parts of Iran's environment. On the other hand, the negative consequences of global warming for the climate of Iran and similar climates are more and more worrying. Therefore, it is essential to take practical and practical solutions instead of evaluations and mere studies. The practical solutions and the production of technology and operational program in relation to these environmental crises require group research in the sub-sectors with together. While, for example, engineers play the most role in controlling superficial fluid (water and dam), But the smallest drought- research related in this area. Therefore, the separate study of each part of these hazards is merely an evaluation and is not a practical way of solving the risk for managers and planners; For example, a water crisis requires a team of researchers such as hydrology, climateology, meteorology, agriculture, urban management, rural, etc. Of course, it should be noted that our researchers have not been trained and not accustomed to group work, and the idea of teamwork is poor in our culture; But there is no way and should start from one point. Perhaps we should start with kindergartens and elementary schools in order to find suitable solutions for at least the next 20 years, researcher’s teams. Finally, it is necessary to address the sustainable development and drought, localization of indicators, operational and management plans based on the environmental capabilities and knowledge of the native area of each region.
 
Keywords: Drought Research, Evaluation, Achievement, Iran.
 
 
 
B Sharifinia Zahra,
Volume 7, Issue 2 (8-2020)
Abstract

Evaluation and Evaluation of Resilience to Drought Hazards in Rural Areas Case Study: rural district Ghare Taghgan Neka
 
Extensive abstract
Concerns over the social, economic, and ecological impacts of climate change on human habitat have increased over the last few decades (McGranahan et al, 2007). According to the UN report, water shortages will occur in the near future in 18 countries, and by 2025 more than two-thirds of the world's population is projected to be in serious water shortages (Pozzi et al, 2013, 191 112; World Bank, 2008, 124). On the other hand, the number of disasters has increased over the past 20 years, reaching 400 from 200 accidents (Pittman et al, 2011, 83,94; Molen et al, 2011, 765-773). In this regard, droughts, the most dangerous natural disasters, affect a wide range of climates and ecosystems, and the geographical areas affected by them have increased rapidly in the last four decades (Kamara et al., 2018, 2318). Drought is a major threat to households and community’s dependent on agriculture for livelihoods (Anthopoulou et al, 2017). Because livelihoods in agricultural-dependent societies are more dependent on climate change (Pittman et al., 2017. (
It is central to the city of Neka; it requires a holistic perspective. The type of applied research and methodology used is descriptive-analytical. Librarian and field method (observation, questionnaire) were used to collect the required data. In order to assess the resilience of rural areas to drought in two economic dimensions (ability to return to employment and income generation and compensation of costs and losses) and in social dimension (awareness, knowledge, skills and preparedness and participation and Collaboration) Designed and developed a Likert-type questionnaire (¬1 very low, 5 = very high). The statistical population of this study is based on census of 6947 households in 24 villages with error of 0.07, ¬191 questionnaire as sample size and based on the relationship of sharing ratio of the number of samples in each village is specified and in villages less than 7 samples, the number has been upgraded to 7. Finally, 233 samples were used as the sample size based on questionnaire completion and analysis and were randomly distributed and distributed among households. To assess the validity of the questionnaire, the experts were first provided with validity and the validity of the research instrument was measured and the final indices and statements were extracted. The questionnaire developed at this stage was pre-tested in the study area and after confirmation of trust or reliability (Cronbach's alpha value of 0.84) the questionnaire was finalized for field research. Descriptive (inferential) and inferential statistical methods (single sample t, Friedman, cluster analysis) and VASP, ARAS and VIKOR models were used to analyze the data. Therefore, in order to evaluate and measure resilience in rural areas, firstly, annual moisture status was investigated based on SPI, SDI and GRI indices. Therefore, the moisture status of the study area during the 13-year statistical period (2006-2007) using the data of 9 Standard Precipitation Index (SPI) rain gauge data, the data of the discharge rate of 6 rivers Surface Flow Index (SDI) and the values Water level level of 9 piezometric wells of GRI index was calculated in DrinC software environment.
 Iran's position on the dry belt and the persistence of droughts over the past two decades have led to the emergence of drought-related crises, especially for villagers who are heavily dependent on water for production, due to climate change. Droughts in the study area were also not exempt from this rule and resulted in adverse effects beyond the normal state and the risk of drought among rural farmers, which could be due to their low level of resilience to this risk. Be it. Therefore, the present study aimed to investigate the economic and social effects of this phenomenon on the status of rural resilience against drought hazards. The results showed that among the sample villages, in the economic dimension, the highest average belonged to Tavaza Abad village of Bostan Khel with average of 3.11 and the lowest average belonged to Plazhartesh village with average of 1.63. In the social aspect, the highest average belongs to the village of Dukhaelo with a mean of 3.54 and the lowest average belongs to the village of Plazhartesh with an average of 1.55. Also, the average real perception of the respondents is less than three and is moderately low, indicating that rural resilience to drought is low.
 
Keywords: Rural Areas, Resilience, Drought, Gharaghgan Village
Alireza Pilpayeh, Davoud Najafian Ghojehbiglou, Tofigh Saadi, Akbar Rahmati,
Volume 7, Issue 3 (11-2020)
Abstract

Drought is one of the natural disasters occurring over a long period of time compared to other natural phenomena which intermittently impedes human societies through the negative impacts on water and agricultural resources and subsequently the economy. One of the methods of drought monitoring is the use of drought indices such as SPI. In this study, SPI index was used to study drought over the period 2001 to 2016. The SPI index is purely based on precipitation, so it is important to select a proper precipitation source to extract the SPI index at different time scales. Synoptic stations, due to lack of proper distribution and high statistical gaps, cannot be a reliable source of precipitation in this type of research, so global precipitation datasets having high spatial and temporal resolution can be used as a viable alternative to ground stations, in this study the Era-interim precipitation product, which is the product of the European Center for Medium range Weather Forecast was used. Initial results indicated that the Era-interim precipitation product could be used as a viable alternative to synoptic stations nationwide. Therefore, this precipitation product was used to assess the drought situation in the country. The study of drought status with respect to SPI indicated that with increasing SPI time scale dry and wet conditions became more severe so that mild dry and wet conditions in most in most month and years turned into severe dry and wet conditions.
 

Nader Shohani, Farshad Shohani, Fariba Shohani, ‎ Hakim ‎ Bakrizadeh, Shamsollah Asgari,
Volume 7, Issue 4 (2-2021)
Abstract

Abstract
Iran and especially the West and Southwest regions of Iran are intermittently confronted with the phenomenon of dust and its problems. West of Iran Due to the natural environment and proximity to areas of dust source in West Asia, a region susceptible to the occurrence of dust phenomena is frequent. Fragments are the most important and perhaps the main threat to the health of individuals. Statistics show the destructive and negative effects of these microorganisms or The same dust is on people in the West and Southwest of Iran. Statistics and studies from the south and west of the country show that more than 100 days have been infected between the years 77 to 91, which has many health problems, and others Items have been created.Method of research In this article, a descriptive-analytical study. Then, using a questionnaire on the relationship between the phenomenon of dust and the health of citizens with the hypothesis: there is a significant relationship between the phenomenon of dust and the occurrence or exacerbation of heart disease in residents of Ilam. This study is a descriptive-analytic study in terms of post-event topic. The statistical population of this study was all patients admitted to Mustafa Khomeini Hospital in Ilam in the years 92-88.
In this paper, we try to first analyze the dust phenomenon, the frequency of its occurrence in the past and recent decades, and investigate the origin and conditions of formation of the phenomenon, and then to the effect Dusty storms on the cardiovascular health of the inhabitants of the area (with an emphasis on the city of Ilam). The results of multivariate statistical analysis including Pearson correlation coefficient, regression test, Chi-square test, ANOVA (variance analysis), and Kundal's correlation test showed that the relationship between the arrival of microorganisms in the statistical period of the study with the number of patients suffering from cardiovascular disease At the significance level, 0.05 was significant and indicates the existence of the relationship. This means that as the amount of entropy to the city of Ilam increased, the number of cases of this disease also increased.
 

Abbas Ali Vali, Mahvash Mehrabi,
Volume 8, Issue 1 (5-2021)
Abstract

Explanation of the subject: The annual drought phenomenon, by affecting economic, social and environmental issues, leads to the vulnerability of urban and rural households and the instability of their livelihoods. Yazd is one of the provinces with drought. Consecutive droughts in the province necessitate integrated management and community adaptation in times of drought.
Method: Taking into account the length of the statistical period of 20 years and to obtain the results with a high level of confidence, the main data of the census documents that have been compiled for the development of cities and villages have been used. By analyzing the main components of several factors, it was selected as the main components. By calculating the standard precipitation index in the arid region, the driest year was determined and by calculating the weighted average of their correlation index with the main components of socio-economic and ecological environment based on appropriate statistical inference. At the end of the year, the effect of drought on different dimensions was presented by step-by-step linear regression, analysis and communication between them to adapt and resilience of individuals in society.
 According to the general results, one of the most important economic and dry economic losses is the annual income of the villagers, which can be due to the decrease in the area under cultivation and production of the main agricultural products. In the social sector, people with knowledge and awareness should increase their adaptive capacity to the occurrence of drought, in order to reduce the vulnerability of social issues to the phenomenon of drought. The results show that unemployment insurance has increased following the drought. The main reason for this is the unemployment of farmers affected by drought, so changing jobs along with temporary migration or the production of handicrafts, etc. can increase the relative income of households at the time of occurrence and prevent unemployment in these conditions. Increasing unemployment will cause other social harms such as poverty, declining health, increasing disease, and reducing judicial and social security. According to the results, one of the components that has established a high standard of rainfall during the drought year is the theft of livestock, which shows a decrease in the social security of the community. People in the study community increase their adaptability to the annual drought by increasing breeding work, such as rangeland improvement, rainfall collection, biological improvement, afforestation, and irrigation reform.
Narges Kefayati, Khalil Ghorbani, Gholam Hossein Abdollahzade,
Volume 8, Issue 2 (9-2021)
Abstract

Regional leveling of drought vulnerability in Golestan province
Narges Kefayati*1-  Khalil Ghorbani2- Gholamhossein Abdollahzadeh 3-
 
1- PhD student of irrigation and drainage, Department of Water Engineering, College  Of Water   Engineering, Gorgan University of Agricultural Sciences and Natural Resources,Gorgan,Iran. (Corresponding Author)*
2- Associated Professor, Department of Water Engineering, College  Of Water   Engineering, Gorgan University of Agricultural Sciences and Natural Resourcesm, Gorgan, Iran.
3- Associated Professor, Department of Agricultural Promotion and Training, Faculty of Agricultural Management, Gorgan University of Agricultural Sciences and Natural Resources
 
Abstract
Drought is one of the natural phenomena that causes a lot of damage to human life and natural ecosystems. In general, drought is a lack of rainfall compared to normal or what is expected, when it is longer than a season or a period of time and is insufficient to meet the needs. Drought causes damage to the agricultural sector. The vulnerability of the agricultural sector in each region depends on three factors: the degree of drought exposure, the degree of sensitivity to drought and the capacity to adapt to drought. A review of previous studies indicates the diversity of indicators and methods used to assess vulnerability, which indicates the importance of the issue. Institutions responsible for agricultural management can only manage drought properly if they have the appropriate tools to measure the vulnerability of the agricultural sector to drought. Therefore, the first step in drought studies is to identify vulnerable areas and assess the vulnerability of areas. Vulnerability measurement in geographical dimensions and measurement of indicators by main vulnerability components have received less attention. Based on this, the present study has investigated drought vulnerability in Golestan by scientific method and by combining the three mentioned components and has compared the exposure situation, sensitivity level and level of drought adaptation capacity among the cities of Golestan province. Golestan province as one of the important agricultural hubs is highly dependent on the amount of annual rainfall. Due to fluctuations in rainfall and drought in some parts of the province, there have been 4 outbreaks and as a result, 7-12 and 10 days of drought have occurred, which has caused severe damage to the livelihood of farming families. Therefore, the aim of the present study was to compare drought vulnerability among cities in Golestan province by three components (exposure, sensitivity and adaptation). First, by reviewing the sources, the effective indicators on drought vulnerability are identified separately by the three components and judged by experts (faculty members of water engineering, agriculture and plant breeding, agricultural extension and education, and agricultural economics and experts of water engineers). 55 appropriate indicators in three main dimensions of vulnerability, namely: a) exposure (14 indicators), b) sensitivity (26 indicators) and c) compatibility (17 indicators) were developed and data related to the indicators were collected. The weights of the indices were extracted by Shannon entropy model and by the TOPSIS method the combined index was compiled separately into three vulnerability components. The final result of the combined index was combined with the GIS layers of the cities of Golestan province, and the level of vulnerability of the cities was determined separately for the desired components. The results showed that in terms of exposure to Bandar-e-Gaz, Bandar-e-Turkmen and Aq Qala are in the first to third ranks, respectively, and are exposed to drought. Azadshahr, Galikesh and Bandar-e-Turkmen counties are in the first to third ranks with the highest sensitivity to drought, respectively. The cities of Gomishan, Galikesh and Maravah Tappeh are the most adapted to drought, respectively. Finally, the results of calculating the total vulnerability index showed that the cities of Marwah Tappeh and Bandar-e-Turkmen are the most vulnerable areas to drought in Golestan province. The findings of this study showed that rainy areas can be more exposed to drought at the same time than other areas and there is no direct relationship between rainfall and drought exposure. This confirms the findings of other studies such as Kramker et al. And O'Brien et al. On the other hand, the findings of this study showed that there is no direct relationship between rainfall and vulnerability to drought and the most  rainy areas of a region at the same time can be the most vulnerable to drought. This is in line with the findings of Tanzler et al. And Salvati et al. On the relationship between rainfall and drought vulnerability. Due to the fact that the rainy areas of this province are more exposed to drought than other areas and farmers in these areas have shown a higher degree of sensitivity to drought and are more vulnerable to drought than other areas, it is recommended Measures should be taken to reduce the sensitivity and increase the adaptation capacity of farmers in these areas.
 
Keywords: Drought, Vulnerability, Exposure, Sensitivity, Compatibility, Regional Leveling
Mrs Laleh Sharifipour, Dr. Mohammad-Javad Ghanei-Bafghi, Dr. Mohammad Reza Kousari, Mr Ssan Sharifipour,
Volume 8, Issue 3 (12-2021)
Abstract

Comparison of the effectiveness of four artificial intelligence methods in predicting drought
Abstract
Problem statement:
Drought is a temporary disorder whose characteristics vary from region to region, therefore, it is not possible to define a complete and absolute definition of drought. Drought is one of the most important natural disasters that can occur in any climate regime. Since drought is unavoidable, it is important to know it in order to optimally manage water resources. Drought prediction can play an important role in managing this phenomenon. In other words, recognizing and predicting this phenomenon is one of the topics of interest for scientists who are interested in solving the problem of water shortage. More than 80% of Iran's area is covered by arid and semi-arid regions and lack of rain is a predominant phenomenon in this region. So far, several methods have been proposed to predict drought. Each method offers different results in specific conditions.  Therefore, identifying the best method for predicting drought in the climatic conditions of central Iran is essential.
 
Material and methods:
In this research, in order to introduce a suitable method for predicting drought for the next month, four methods of artificial intelligence including Deeplearning (using the Alexnet network, one of the convoluted networks), K nearest neighbor algorithm (KNN), multi-class Support vector machines (SVM-MultiClass) and decision tree have been used. Monthly rainfall data from 11 syntactic stations of Yazd province during the 29-year statistical period (1988 to 2017) were used as experimental data. Standardized precipitation index (SPI) was calculated to indicate drought status in terms of severity and duration on 1, 3, 6, 9, 12 and 24 month time scales. Precipitation data was used as neural network input and SPI classification as network output and 80 percent of the data was used for training and 20 percent for testing the networks.
In this study, the Recurrence Plot method was used to interpret the time series to convert these series into images and RG and B pages were created. To convert rainfall data into photos at 1, 3, 6, 9, 12 and 24 month time scales, photo layers were created using a standardized rainfall formula, and by merging these three output layers into colored photos and black and white photos were obtained. Using three pages created in MATLAB software and merging them, the output was in the form of a photo, which was placed as the input of the Alexnet network. Combination of Recurrence Plot to create images and deep learning network for classification of drought data has been used for the first time in this research. To evaluate the effectiveness of the classification strategy, standard criteria of accuracy, micro-F1 and macro-F1 were used.
 
Results Description and interpretation:
 The results showed that all networks were able to predict drought. However, on short time scales such as 3 and 9 months, the accuracy assessment criteria for some classes are zero and the methods of learning from these classes are practically ignored due to their lack of data. But on a larger time scale, this issue has been addressed and the data of those classes are well categorized. Deep learning network with image input could not predict well in the short term due to lack of data, but in the long term due to increased data has improved its performance and had the best performance. The SVM method at different time scales has shown unreliable and variable behaviors that can not be said to be a suitable method for predicting drought at different time scales. Decision Tree and KNN methods have been able to predict drought better in the short term than in the long term. The two methods have been closely related. .Based on the Deeplearning network macro-f1 evaluation criterion, the one-month time scale with 22.71% was the most inefficient method and the Decision Tree with 64.65% was the most efficient method, But with the increase in time scale, the Deeplearning network improved its performance, so that at the 24-month time scale with 65.35%, the best performance for the Deeplearning network followed by the SVM-MultiClass network with 57.40%. For future research, it is suggested that Decision Tree and KNN methods be used to predict short-term drought. In this study, with increasing the time scale and increasing the data used, these two methods have lost their effectiveness compared to the short term.
 
key words: Drought, Standardized Precipitation Index, Artificial Intelligence, Deep Learning, Alexent, Recarence Plot
 
Zahra Arabi, Ayub Badragh Nejad,
Volume 8, Issue 4 (3-2022)
Abstract

Introduction
Drought is one of the environmental disasters that is very frequent in arid and semi-arid regions of the country. Rainfall defects have different effects on groundwater, soil moisture, and river flow. Meteorological drought indices are calculated directly from meteorological data such as rainfall and will not be useful in monitoring drought if the data are missing. Therefore remote sensing technique can be a useful tool in drought measurement. Drought is a recognized environmental disaster and has social, economic, and environmental impacts. Shortage of rainfall in a region for long periods of time is known as drought. Drought and rainfall are affecting water and agricultural resources in each region.
Materials & Methods
The present study is a descriptive-analytic one with emphasis on quantitative methods due to the nature of the problem and the subject under study. In this study, the Tera Sensor Modis satellite images from 2000 and 2017 were used to verify the existence of wet and drought phenomena. In the next step, by examining the rain gauge and synoptic data of the existing stations and using a standardized precipitation index model of three months (May, June and April), the sample was selected. Next, we compared the temperature status indices (TCIs) and vegetation health indices (VHIs) in these three months to determine the differences in these indices over the three months. Modi satellite Tera satellite was used to find out the vegetation status in the study area. Subsequently, using the condition set for the NDVI layer, the vegetation-free areas were separated from the vegetated areas. Experimental method was used to determine the threshold value of this index. For this purpose, different thresholds were tested, with the optimum value of 1 being positive. NDVI is less than 1 plant-free positive and more than vegetation-free. MODIS spectral sensing images for ground surface temperature variables, with a spatial resolution of 1 km, including bands 31 (bandwidth 1080/1180 central bandwidth / 11.017 spatial resolution 1000 m) and 32 bands- 770/11 Central Wavelength Band 032/12 Spatial Resolution Power (1000 m) Selected for months that are almost cloudless. All images have been downloaded from the SearchEarthData site and have been edited. The total rainfall of June, April, and May for the 20-year period was provided by the Meteorological Organization of Iran. ARC GIS software and geostatistical methods were used to process the Excel data. Also, to estimate the correlation between the data Pearson's correlation coefficient was used.
Results & Discussion
The standardized precipitation index is a powerful tool in analyzing rainfall data. The purpose of this study was to compare the relationship between remote sensing indices and meteorological drought indices and determine the efficiency of remote sensing indices in drought monitoring. Correlation between variables with SPI index was evaluated and calculated. The results of the indicators are different, so a criterion should be used to evaluate the performance of these indicators. SPI index on quarterly time scale (correlated with vegetation) as the preferred criterion Selected. According to the results of correlations, the TCI index with the SPI index had a strong correlation with other indices. In the short run, this index has the highest correlation with thermal indices at 1% level. The correlation between meteorological drought index and plant water content and thermal indices increases with increasing time interval. Positive correlation between vegetation indices and plant water content with meteorological drought indices indicates that trend of changes is in line. Therefore, the TCI index makes drought more accurate and is a better method for estimating drought.
Conclusion
The results showed that among the surveyed fishes, the highest drought trend was observed in the eastern part of these provinces and covered more than 50% of the area. The trend of changes in this slope was statistically significant. According to the results of correlations, the TCI index with the SPI index had a strong correlation with other indices. It can also be concluded that the Modis images and the processed indices along with the climate indices have the potential for drought monitoring. Using maps derived from drought indices can help improve drought management programs and play a significant role in mitigating drought effects.
Keywords
Drought, remote sensing, correlation, climate index.
 


Page 1 from 2    
First
Previous
1
 

© 2024 CC BY-NC 4.0 | Journal of Spatial Analysis Environmental hazarts

Designed & Developed by : Yektaweb