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Showing 10 results for Ars

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.


Alireza Mohammadi, Bahman Javid Moghvan,
Volume 3, Issue 3 (10-2016)
Abstract

Most of the large cities in developing countries have faced with the problem of informal settlements. The formation and growth of these settlements for reasons such as rapid and outside the customs building construction are the threatening issue for their communities. Informal settlements are areas that often shaped and expanded in major and middle cities of the Iran’s cities including the city of Parsabad. During the last decades, the rapid growth of urbanization and the lack of appropriate planning for low-income families housing leads to the formation of the urban informal settlements in most cities of the Iran. In most cases, these settlements have a structural and demographic dense texture. The structural texture of these settlements is often fine aggregate, impermeable, and unstable. In times of crisis, the possibilities of human and material losses to them are high.

Environmental hazards such as earthquakes are a serious threat to these settlements. However, these hazards in most developing countries, due to the unavailability and lack of preventive actions, end to the crisis. We cannot prevent earthquakes. But we can reduce the losses and damages caused by the earthquakes. Remove of the disaster is impossible, but it is possible to reduce the damage caused by the disaster. One of the most important ways to reduce the risk of earthquakes is preparation to deal with earthquakes. Preparation means having previous programs and plans.

     Iran is one of the countries where earthquakes always happen. Because Iran located in the world's earthquake belt, each year on average about 1,000 earthquakes happening in Iran. Ardebil and Pars-Abad city, located in an area that the possibility of earthquakes shakings in these areas, is more. The Zire Nahre Torab Neighborhood is one of the Parsabad city’s informal settlements that located in the northwest of the city. Regarding the possibility of an earthquake in the city of Pars Abad, identification and assessment the vulnerability of the neighborhood during an earthquake, is essential. Therefore, identifying and assessing the vulnerability, especially in the poor neighborhoods to offer strategies for dealing with the injuries, is essential. The aim of this study is assessing vulnerability of the informal settlements during an earthquake by using spatial data and GIS. This study, have been prepared in fifth main parts including: introduction and background, methodology and presentation of case study, theoretical framework, analysis and conclusions.  

This research in terms of the nature is practical and is descriptive and in terms of the method is analytical. Three methods including library, documentary and survey have been used for data collection. In the first phase, data and base maps were extracted from documents and reports of projects such as city comprehensive and detailed plans. Also, in this phase of the study data were updated. In the second phase, the problem, questions and research objectives were defined. In the third phase, the 3 criteria and 12 sub-criteria based on research literature and according to available data were selected. In the fourth phase, after preparation of databases related to each of the criteria in GIS, input layers were prepared for each of them. In the fifth step, the method of network analysis process (ANP) was used to determine the significance of criteria. In the sixth phase, the weighted overlay index (WOI) was used for combining output layers.

The results of this study show that more than 80% of neighborhood buildings are vulnerable against the risk of a possible earthquake. Also, research findings suggest that physical characteristics such as building structure, quality and age of the buildings will have the greatest role in determining the neighborhood buildings vulnerability level. Doing activities such as resisting buildings, improving roads, locating facilities in appropriate places, training and informing citizens to prevent a crisis caused by the possible earthquakes, is essential. Other recommendations are listed in below:

  1. Identifying vulnerable buildings
  2. The use of GIS in the management of settlements
  3. Preparations cities, to deal with urban hazards
  4. Empowering citizens to deal with environmental hazards
  5. Action to reduce earthquake risk
  6. Civil engineering Renovation of buildings
  7. New practices in the urban construction
  8. Equip cities with facilities and relief supplies.
  9. The use of specialists in urban planning.
  10. Conducting workshops on urban resilience.


Aliakbar Anabestani, Mahdi Javanshiri, Hamideh Mahmoudi, Mohammad-Reza Darban Astaneh,
Volume 5, Issue 1 (6-2018)
Abstract

Spatial Analysis of Villagers’ Resilience Against Environmental Hazards
(A Case Study of Central District of Faruj County)
Statement of the problem
The concept of resilience is the outcome of changes in risk managing in current decade. Today, the views and theories of disaster management and sustainable development seek to create societies resilient against natural disasters. Natural disasters such as earthquakes, droughts, floods, etc. are inevitable phenomenon which always pose a serious threat to development, especially in rural areas. This reflects the need to pay more attention to resilience in local level (rural areas). Resilience is the ability of a social or ecological system to absorb and deal with disorder or disturbance, so that the basic functional structure, can maintain the capacity of reorganization and adapting to changes and tensions. Carpenter defines resilience as the capacity of an environmental and social system to absorb a disruption, reorganize and thereby maintain essential functions. Thus, in order to reduce damage caused by natural disasters, the capacity of rural areas to deal with these events should be increased. Increased level of resilience against natural hazards is possible through accurately identifying the factors affecting resilience. Therefore, the aim of this study is the spatial analysis of factors affecting the promotion of rural environmental resilience in the face of natural hazards in rural areas of Faruj County.
In fact, the present study seeks to answer the following questions: what are the factors which may increase the level of resilience in the sample communities exposed to natural hazards, and how resilient are the sample villages of the study?
Research Methodology
This study is an applied research conducted in a descriptive-analytical method based on questionnaires. Data were collected through library research and field works which required completing questionnaires and conducting interviews with villagers living in the Central District of Faruj County.
Validity of the questionnaires was confirmed based on experts' views and its reliability was calculated using Cronbach alpha for different dimensions. The population consisted of 4591 households from the villages suitable for temporary accommodation. Based on the Cochran formula, 252 were obtained from these samples. They were selected by stratified random sampling.
Using statistical analysis methods in SPSS software, we analyzed the data to measure resilience in sample villages of the study area. We also used Excel and GIS in various parts of the study. To determine the best option, we used the VIKOR models, Gray relational analysis and Additive Ratio Assessment (ARAS).
Results and discussion
The results showed that infrastructure dimension with a mean of 2.92 and the economic dimension with a mean of 2.58 respectively had the highest and least impact on increased resilience which suggest that these villages compared to sample villages have relatively good infrastructure facilities. However, due
to the lack of proper institutional framework and poor performance of crisis management institutions, villagers are less satisfied with these organizations. Accordingly, based on t-test, the actual mean of the total respondents’ views was less than 3 and at the moderate level, and the economic index with the t statistics of -10.38 had the most negative impact on the resilience of the villagers.
It should be noted that according to the results of the resilience correlation with the individual characteristics of the respondents, it became clear that the gender and marital status has a direct and weak relationship with each dimension of resilience, which means men and the married people compared to the women and the singles believe their villages are more resilient. Besides, there is a weak and reverse relationship between the education of the individuals and their resilience, meaning that people with lower education compared to educated people, believe their villages are more resilient. There was no relationship between age and the dimensions of resilience.
In order to assess the impact of each index of the study on the level of resilience in the villages of the study, the confirmatory factor analysis test was used which revealed that among the indices of the study, "the villagers’ satisfaction with the performance of the Rural Council and administers (Dehyars)", "the role of institutions in educating people about various incidents" and "the use of new and durable materials to prevent the damaging effects of the incidents" had the greatest effect on the resilience of the samples villages.
Eventually, to determine the best village in terms of resilience for establishing a temporary settlement site in crisis management, we use three techniques: additive ratio assessment (ARSA),- VIKOR and Gray relational analysis. We prioritized the villages based on the mean rank method. -Considering the indices of resilience in the rural areas of the study, the villages of Mefrangah, Ostad and Pirali have the highest ranks, and the villages of Rizeh and Roshavanlou have the lowest ranks.
Key words: resilience, environmental hazards, organizational-institutional dimension, additive ratio assessment (ARSA), Faruj Central District
, , , ,
Volume 5, Issue 4 (3-2019)
Abstract


 Extended  Abstract
Cold and frost is one of the most important climatic parameters in the agricultural climate, and the damage caused by them reduces the possibility of producing many agricultural and horticultural products in vulnerable areas. Cold and frost is one of the climatic hazards that annually causes damage to various activities. The agricultural sector is the most important part of the damage that is most seriously damaged by frost. Cold and frosty weather for many crops and gardens results in harmful and destructive consequences, in some years billions of rials damage farmers, farmers and, ultimately, the national interests of the country. Considering that the northwest region of Iran suffers a lot of financial losses each year due to atmospheric hazards especially cold and frost. Identification and zoning of areas with high potential of cold and frost hazard and prediction of their occurrence can provide valuable and valuable information for preventing and mitigating damages. In this study using HadCM3 global model under two scenarios A2 and B1 and The LARS-WG microscope model is dealt with this.
It is important to check the time of occurrence and predict their future changes. For this purpose, general atmospheric circulation (GCM) models are designed that can simulate future climate parameters. In this study, the output data of the HadCM3 general circulation model under two scenarios of A2 and B1 were analyzed by LARS-WG statistical method in 21 synoptic stations located in northwest of Iran. The results of this study were based on the base period (1980-1989) and The 2020 decade (2030-2011) was evaluated for two climate variables: minimum temperature and maximum temperature. Then the history of the first and last frost and cold of autumn and spring was extracted and their date of occurrence was calculated in the future.
The monthly average of the minimum temperature of the stations studied in the course of the 2020s and the base period shows that the temperature has been increased according to both scenarios and increased in all months and at most study stations compared to the base period. The maximum changes in the minimum temperature in the study area are based on the average scenarios in this decade related to Abhar, Ardebil, Khoy and Urumieh stations at 0.8 degrees Celsius; In fact, the minimum temperatures that occurred at these stations during the base period have not been observed in the next period and the heating process has shown that its rate in the region of the study area in the 2020s is between 0.4 and 0.8 It will be in the base period. The results indicate an increase in the monthly average of the minimum and maximum daily temperatures in the upcoming period to about 0.8 degrees Celsius. The results of the first and last glacial survey in the decade of 2020 indicate that the first glacial precipitate of autumn occurs between 2 and 9 days later, with the least change in the history of frost occurring in two stations of Qazvin and Meshkinshahr each with 2 The change day is relative to the base period. The last frost of late spring also will be 3-10 days earlier on the surface of the region. However, the duration of the ice free period will be reduced at all stations, which is the highest decrease for Khoy station with 16 days, then the stations of Urmia and Ardebil each Two with 14 days and the lowest decrease is due to Meshkinshahr station for 6 days. Based on the results of changes in the date of early ice ages, changes are less than the late frost. Based on this, the study of the condition of glaciers and serma in most of the studied stations shows that the first frost and autumn frost in the coming period will start earlier and the cold and the frostbite will end sooner. The least changes were observed in the south-east of the study area, Meshkinshahr and Sarab regions, and the most changes in the glacial period were related to Khoy, Urmia, Tabriz and Ahar areas. According to the results of most studied areas, averaging between 10 and 12 days decrease in length The ice age will experience the base course.
The results indicate an increase in the monthly average of the minimum and maximum daily temperatures in the upcoming period to about 0.8 C. Based on this, the study of the condition of glaciers and serma in most of the studied stations shows that the first frost and autumn frost in the coming period will start earlier and the cold and the frostbite will end sooner. Also, the length of the cold and freezing period is decreasing, which may reflect the consequences of climate change at study stations. The results of this study are based on the studies of Grasick and Dodwilich (2015) in Poland, Medella et al. (2016) in Texas, Hosseini and Ahmadi (1395) in Saqez, Aqa Shariatmadari et al. (1395) in West Iran, Sobhani et al. (1396). ) In Ardebil and Khalili et al. (1396) in Iran.
 
Hassan Zohrevandi, Ali Mohamad Khorshid Dost, Behroz Sari Saraf,
Volume 7, Issue 1 (5-2020)
Abstract

Prediction of Climate Change in Western of Iran using Downscaling of HadCM3 Model under Different Scenarios
 
Hassan Zohrehvandi 1, Ali Mohammad Khorshiddoust 2, Behrouz Sari Sarraf 3

1- Ph.D student of Climatology, University of Tabriz, Email: 
H.zohrehvandi@gmail.com 
Mobile number:+989181502513
2 - Associate Professor of Climatology, University of Tabriz, Email:         

 Mobile number:
 3- Associate Professor of Climatology, University of Tabriz, Email:      
 Mobile number:
 
Abstract
   Considering that water resources are at risk from climate change, the study of temperature and precipitation changes in the coming years can lead to droughts such as droughts, sudden floods, high evaporation and environmental degradation. To this end, global climate models (GCMs) are designed to assess climate change. The outputs of these models have low spatial accuracy. In order to increase the spatial accuracy of this data, downscaling methods are used which are divided into statistical and dynamic methods. One of the reasons for using these models is their quick and easy operation compared to other methods. Our study area consists of Kurdistan, Kermanshah and Hamedan provinces in the west of the country. In this study, observational data of minimum temperature, maximum temperature, precipitation and radiation of 6 synoptic stations in the studied area in the statistical period of 1961 until 2005. In this study, the LARS-WG model was used for downscaling of HadCM3 global model data. The LARS-WG model is one of the most popular weather generator models that which to generation for maximum and minimum temperature, rainfall and radiation are used daily under current and future climate conditions. This model as a downscaled version of the same process less complex and simulated data input and output, high ability to predict climate change. The HadCM3 model is also a type of atmospheric- oceanic circulation model developed at the Hadley Center for Climate Prediction and Research, which has a 2.5 degree latitude network at 3.75 degrees longitude. Also, three climate change scenarios A1B, A2 and B1 have been used, each of which reflects the characteristics of the world's economic growth, the world's population and social awareness. The methodology is that the model receives the monitored data of the basic course; by examining them the statistical characteristics of the data are extracted. Then, in order to validate and ensure the model's capability for the basic statistical period, the model is implemented to re-establish a series of artificial data in the base period. Then the outputs to evaluate the performance of the model in the reconstruction of the data, the statistical characteristics of observations to test and compare various criteria. MAE, MSE, RMSE and R2 criteria were used to evaluate and analyze the performance of the downscaling model. The results showed that the accuracy of the model varies in different stations and parameters, so that the model in simulation of temperature and radiation is more suitable than rainfall simulation. Also, the model has more successful in simulation of maximum temperature in comparison with minimum temperature. In sum, the results of different evaluation criteria indicate that the LARS-WG model has a good accuracy for the downscaling of the parameters studied in the study area. After evaluating the LARS-WG model and ensuring its appropriateness, the data was generated by the model for three climate change scenarios using the HadCM3 model. The results of the monthly review of the parameters studied at the station indicate that precipitation in the 2050s at all stations except Saralpul Zahab and Sanandaj stations according to the three scenarios studied in most months except December, January And at some stations, sometimes in November and February, they were lower than the base period, and rainfall is expected to decrease over the 20 years period (2046-2065), but the situation for Sanandaj and Saralpul Zahab stations is somewhat different, which, according to some scenarios, has increased in most months of the year, and according to some scenarios, rainfall has decreased in some months and it seems that the precipitation pattern is shifted The end of the warm season. But the rainfall situation is completely different in the 2080s, and rainfall has decreased in all stations and in most months of the year. The average monthly of the minimum and maximum temperatures as well as the amount of radiation shows that all three parameters will increase in all months of the year based on all three scenarios, as well as in the two decades studied (2080 and 2050) And its rate would increase in the decade than in the previous decade. According to the results, the amount of precipitation decreases in study area and the temperature and radiation will increase as well. The rate of precipitation decrease in the following periods will be 7.7% in the region than in the base period, and the minimum and maximum temperatures in the long-term was increase at the region 3.4 and 3.4 degrees Celsius, respectively, compared to the average period of the base. The radiation increase was 0.38 mJ /m2 in Area level. The results of this research can help to solve the challenges of water resource managers and planners in future periods.
 
Keywords: Climate Change, downscaling, west of Iran, General Circulation model, LARS-WG
 
 
 
 
Dr Hassan Lashkari, Miss Neda Esfandiari,
Volume 7, Issue 2 (8-2020)
Abstract

Identification and synoptic analysis of the highest precipitation linked to ARs in Iran
 
              Abstract
        Atmospheric rivers (ARs) are long-narrow, concentrated structures of water vapour flux associated with extreme rainfall and floods. Accordingly, the arid and semi-arid regions are more vulnerable to this phenomenon. Therefore, this study identifies and introduces the highest precipitation occurred during the presence of ARs from November to April (2007-2018). The study also attempted to demonstrate the importance of ARs in extreme precipitation, influenced areas and identifies the effective synoptic factors. To this end, integrated water vapour transport data were used to identify ARs, and documented thresholds applied. AR event dates were investigated by their daily precipitation, and eventually, ten of the highest precipitation events (equivalent to the 95th percentile of maximum precipitation) associated with ARs were introduced and analyzed. The results showed that most ARs associated with extreme precipitation directly or indirectly originated from the southern warm seas. So the Red Sea, the Gulf of Aden and the Horn of Africa were the major source of ARs at the time of maximum IVT occurred. Synoptically, seven AR events formed from the low-pressure Sudanese system and three events from integration systems. The subtropical jet was the dominant dynamic of the upper troposphere, which helped to develop and constant of ARs. Moreover, the predominant structure of jets had a meridional tendency in Sudanese systems, while it was a zonal orientation in integration systems. The intense convective flows have caused extreme precipitation due to the dominance of strong upstream flow besides having the highest moisture flux. The station had the highest precipitation has been located in the eastern and northwestern region of the negative omega field or upstream flows.
 
        Keywords: Identification and synoptic analysis, highest precipitation, Ars, Iran.


Dr Amir Saffari, Dr Ramin Hatamifard, Dr Mansor Parvin,
Volume 8, Issue 1 (5-2021)
Abstract


 Karst Geomorphology effects on the environmental hazard intrinsic vulnerability of groundwater resources (Case study: the Aleshtar and Nourabad basins)
 
Introduction
Karst is the result of the dissolution (physical and chemical) in carbonate (limestone and dolomite) and evaporate rocks. Karst developing is affected by climatological and geological factors. In the other words Karst landscapes and karst aquifers are formed by the dissolution of carbonate rocks by water rich in carbon dioxide waters. Karst aquifers include valuable freshwater resources, but are sometimes difficult to exploit and are almost always vulnerable to contamination, due to their specific hydrogeologic properties, therefore, karst aquifers require increased protection and application of specific hydrogeologic methods for their investigation. The groundwater protection in karst aquifer has a special importance, because the transit time for unsaturated and saturated zone is so quickly that the attenuation of the pollutant. Karst groundwater vulnerability mapping should form the basis for protection zoning and land use planning. A conceptual framework was devised for vulnerability mapping based on this European approach.
Social and economic life of cities such as Nourabad, Alashtar, and numerous rural societies is connected to the Gareen anticline springs. In this paper we used PaPRIKa method for vulnerability assessment in the Aleshtar and Nourabad basins.
 
Material and Methods
 The Gareen anticline in the Zagros Mountain range is located in the active deforming Zagros fold-thrust belt and Sanandaj-Sirjan zon. Alashtar and Nourabad karst aquifers are located in the north of Lorestan province. There are several thrust faults with northwest–southeast strike such as Gareen-Gamasiab and Gareen-Kahman Faults. Nourabad unit is composed mainly by gray limestone rocks, embedded marl limestone, recrystallized limestone and pyroclastic rocks. One of the most important features of the structural geology of the Alashtar unit, is abundance of the sedimentary rocks and scarcity of igneous rocks in this area. In other words In the Study basins the main geological formations incloud: Bakhtiarian conglomerate, carbonates of Sormeh, Taleh Zang, Pabdeh and Kashkan Formations.
The groundwater vulnerability assessment methods (PaPRIKa) applied at the test sites were designed specifically for karst aquifers. They are based on various types of information concerning the physical characteristics of the unsaturated and saturated zones, the aquifer structure and its hydrological behavior.
The PaPRIKa method takes into consideration criteria for both structure and functioning of the aquifer. Based on EPIK and RISK resource methods, PaPRIKa method was developed as a resource and source vulnerability mapping method, allowing assessing vulnerability with four criteria: Protection, Rock type, Infiltration and Karstification. The P map (Protection) considers the protection provided to the aquifers by layers above the aquifers: the S (soil texture, structure and thickness), Ca (permeability formations), the Uz (thickness, lithology and fracture degree of unsaturated zone) and E (Epikarst aquifer). Moreover, including the catchments of water losses where the vulnerability is higher. R map (Rock type) considers the lithology and the degree of fracturing of the sutured zone. I map (Infiltration) distinguishes concentrated from diffuse infiltration. Ka map (Karstification development) assesses the drainage capacity and the organization of the karst conduits network.
To  calculate  the vulnerability  index,  the  four  mentioned  maps(P. R. I. Ka)  have been  combined  using  the  following  equation coefficients (eq.1):
 
PaPRIKa Index= 0.2 P + 0.2 R + 0.4 I + 0.2 Ka                                        (1) eq
 
Due to the fact that karst geomorphology has a great impact on the quantitative and qualitative characteristics of water resources and the vulnerability assessment of these resources, fuzzy logic has been used to zonation of the Karst development in the Aleshtar and Nourabad basins.  In the fuzzy method used a gamma operator (eq.2):
µ Combination= ((Fuzzy Algebraic Sum) (Fuzzy Algebraic Product)) 1-γ                                                (2) eq                    
The vulnerability map for aquifers was prepared using the software Arc GIS10.4.
 
Discussion and Results
In the Gareen Antarctic region, due to the availability of suitable Karstification, includes: Lithology, Active Tectonics, Mediterranean climate (with average rainfall of between 454-448 mm and average temperature of 13 C˚) features are formed by various forms of karst such as closed pits (Doline, Swallow Hole, Aven, Polyeh (Peljee), several types of Karrens, dissolution Cavities, small and large Caves and Springs. The most important karst features in this area including Dolines (Solutional, Collapse, Subsidence and Dropout) which are known the Karst Nival. Based on the Karst development zoning map by using the fuzzy logic, 15% of the study area has been developed. Due to the vulnerability based on PaPRIKa method, the Aleshtar and Nourabad basins divided into 5 categories. Resuls show that the vulnerability of the study area is mainly classified as High or Very High, due to the highly developed Epikarst, which minimizes the protective function of the unsaturated zone. There are many karst landforms such as dolines and Swallow Holes that are highly vulnerable.
 
Conclusions
The final evaluation of the vulnerability ground waters in the Aleshtar and Nourabad basins using the PaPRIKa method shows that the study area is divided into five vulnerable (very high, high, moderate, low and very low). So that areas with a very low, low and moderate vulnerability are 27.3%, 22.3% and 20.6% of the basin area respectively. Also that areas with a high and very high vulnerability are 17% and 12.8% of the study area cover, respectively. Due to the lack of soil and plant cover, heavy snowfall and the formation of Karst-Nival (including Dolines) highlands of the Gareen Anticline have a very high vulnerability potential. Validation of the results of the karstic aquifers vulnerability to Electrical Conductivity (EC) data and monthly discharge of springs shows that the Zaz and Ahangaran springs are in a high vulnerability zone. In the aquifer of this springs, Rapid reductions in EC are detected after each recharge period. Also in contrast Rapid increases in EC with reductions in recharge. This situation shows the High developed of this aquifers, as a result, the potential for vulnerability in these aquifers is high.
But in the springs of Niaz and Abdolhosseini in the Nourabad basin, the EC chart has not changed much compared to recharge. Therefore, the aquifer of these springs is less undeveloped or low developed and also less vulnerable.
 
Key Words: Gareen Anticline, Geomorphology, Karst, Lorestan, Pa
 
 
Mr Mohammad Hossein Aalinejad, Pro Saeed Jahanbakhsh Asl, Pro Ali Mohammad Khorshiddoust,
Volume 8, Issue 3 (12-2021)
Abstract

Investigation of Temperature and Precipitation Changes in the Seymarreh Basin by Using CMIP5 Series Climate Models
 
Abstract
Panel reports on climate change suggest that climate change around the world is most likely due to human factors. Temperature and precipitation are two important parameters in the climate of a region whose variations and fluctuations affect different areas such as agriculture, energy, tourism and so on. Seymareh basin is one of the most significant sub-basins of Karkheh. The purpose of this study is to predict the impact of climate change on precipitation and temperature of the Seymareh Basin in 2021-2040 period. These effects were analyzed at selected stations with uncertainties related to atmospheric general circulation models (GCMs) of CMIP5 models under two scenarios of RCP45 and RCP85 through LARS-WG statistical model. Then the uncertainties of the models and scenarios were investigated by comparing the monthly outputs of the models by the coefficients of determination coefficient (R2) in the forthcoming period (2021-2040) with the base period (1980–2010). The root mean square error (RMSE) calculations presented the best model and scenarios for generating future temperature and precipitation data.            
The Seymareh catchment is the largest and the main Karkheh sub-basin that covers parts of Kermanshah, Lorestan and Ilam provinces. The length of the largest river at the basin level to the site of the Seymareh Reservoir Dam is approximately 475 km, and the area of the basin is 26,700 km2. Geographic coordinates of the basin are from 33° 16 ́ 03 ̋to 34°59 ́ 29 ̋north latitudes and 46°6 ́9 ̋to ̋ 5 ́ 0 ° 49 Eastern longitudes, minimum basin height 698 m at the dam outlet and its maximum height 3,638 m. It is on the western highlands of Borujerd.
The information used in this study was obtained from the Meteorological Organization of the country. For this study, three synoptic stations of Kermanshah, Hamadan and Khorramabad, which had the highest statistical records and had appropriate distribution at basin level, were used. These data included daily and monthly temperature and precipitation information, and sunshine hours.
The LARS-WG fine-scale exponential model was proposed by Rasko et al., Semnoff and Barrow (1981). We used daily data at stations under current and future weather conditions. In order to select the best GCM model from the models mentioned above, minimum temperature, maximum temperature, precipitation and sunshine data were entered daily in the base period (1980–2010) and data were generated for five models under two scenarios of RCP45 and RCP85 for the period 2040–2021. The data were generated in 100 random series and the mean of required variables (minimum temperature, maximum temperature and rainfall) were extracted monthly in the period 2021-2040. Then, root mean square error (RMSE) and determination coefficient (R2) were used to evaluate the performance of the models and compare the results.
To ensure the models' ability to generate data in the coming period, computational data from the model and observational data at the stations under study should have been compared. The capability of the LARS-WG model in modeling the minimum temperature, maximum temperature, and radiation at the stations under study was completely consistent with the observed data. The model's ability to exemplify rainfall was also acceptable, however the highest modeling error was related to March rainfall.
By comparing the observed and produced data including monthly average precipitation, minimum and maximum temperatures through five mentioned models with their indices, the best model and scenario for future fabrication were determined. The results of this comparison showed that among the available models, HADGEM2-ES model under RCP 4.5 scenario had the best result for precipitation and HADGEM2-ES under RCP 8.5 scenario predicted the best result for maximum temperature. Determining the best model, precipitation data, minimum temperature and maximum temperature produced in the selected models and scenarios were analyzed to investigate the climate change temperature and precipitation for the future period.
The results of this study indicated that due to the wide range of output variations of different models and scenarios, by not taking into account the uncertainties of the models and scenarios can have a great impact on the results of the studies. It was also found in this study that the LARS-WG exponential model was capable of modeling precipitation data and baseline temperature in the study area, so that the radiation data, minimum and maximum temperatures were completely consistent with the data.
The observations are consistent and the models' ability to predict rainfall is very good and acceptable manner. In investigating the uncertainties caused by atmospheric general circulation models and existing scenarios, the best model to predict precipitation in the study area is HADGEM2-ES model under RCP 8.5 scenario, the best model for temperature estimation model HADGEM2-ES under RCP scenario No. 4.5.
The overall results of this study revealed that the average precipitation in the basin will decrease by 4.5% on average, while the minimum temperature will be 1.5° C and the maximum temperature will be 2.17° C. The highest increase will be due to the warmer months of the year. Notable are the disruptions of rainfall distribution and the high temperatures will have significantly negative consequences than rainfall reduction.
 
  • : Climate Change, Climate Scenarios, Uncertainty, LARS-WG, Seymareh.
 
 

Fateme Emadoddin, Dr Amir Safari,
Volume 9, Issue 4 (3-2023)
Abstract

 Vulnerability assessment of karst aquifer using COP and PI model (Case study: Bisotun and Paraw aquifers)


 Introduction
Drinking karst water resources, especially in arid and semi-arid regions, like Iran, are considered as valuable and strategic water resources. A sharp decrease in rainfall reduces the quality and quantity of karst water sources (Christensen et al., 2007). On the other hand, urban and industrial development, which is accompanied by the increase in population growth, increases the risk of underground water pollution caused by the dumping of chemicals, waste and change of use (McDonald et al., 2011). Protection of karst aquifer is one of the most important measures in the management of karst water resources due to its vulnerability and high sensitivity to pollution (Khoshakhlagh et al., 2014, Afrasiabian, 2007). Therefore, With the advancement of geographic information system technology, rapid progress was made in the ability to identify and model groundwater pollution, as well as the vulnerability of water sources from these pollutants (Babiker et al., 2004, Rahman, 2008). The pollution potential decreases from the center to the periphery (Saffari et al., 2021).

 Materials and methods
In this study to evaluate the vulnerability of Bisotun and Paraw aquifer which is karstically developed and has, crack and fissure and various landforms; COP and PI vulnerability models have been used to identify areas at risk of contamination. The COP model includes three main factors including concentration of flow (C), overlaying layers (O) and precipitation (P). Factor C, which indicates surface features (Sf), slope and vegetation (Sv). It was obtained between 0.8-0.0 in 5 classes. From the overlap of the subfactores soil, layer index and lithology, the O factor map was prepared in three classes, including class 2 with low protection value, 2-4 with medium protection value and 4-8 with high protection value.  The P factor, which is the temporal distribution of precipitation along with the intensity and duration of precipitation, can show the ability of precipitation to transfer pollutants from the surface to the underground water. P factor was 0.8 in 2 layers in the northwest of the study area and 0.8-0.9 with low protection value. Furthermore, top Soil, precipitation, net recharge, fracture density, bedrock and lithology maps were used for the protective cover factor (P) in the PI model. The zoning of the P factor showed 2 classes such as very low and low most of the study area is in the low class. The infiltration condition factor (I) using the characteristics of the soil, the slope layer, and the land use in four layers showed high, aamedium, low, very low, which due to the high slope of the area of ​​the high layer has the highest dispersion, which causes the reduction of the protective cover.

 Results and discussion
Consequently, COP vulnerability map in 5 classes with very high vulnerability (0-0.5) equal to 38774.74 hectares (41.4%) and very low vulnerability (4-9-4) with 57.86 hectares (0.06%) of the largest and smallest area respectively. Also, the PI vulnerability map of the combination of these two factors showed very high vulnerability with the largest area of ​​about 68,783 hectares and 72.9% scattered throughout the study area and the high vulnerability class with an area of ​​about 25,526 hectares and 27%.

 Conclusion
The results of this research showed that the simulation performance of each COP and PI vulnerability model is closely related to the amount of pollution in the environment. It seems that the COP vulnerability model can better and more accurately showed the level of vulnerability in the karst aquifers of Bisotun and Paraw.



Keywords: karst aquifer, Bisotun and Paraw, COP model, PI model, vulnerability.


 

Mr. Aliakbar Mirshafie, , ,
Volume 11, Issue 2 (8-2024)
Abstract

Assessment of the measurement statistics of model accuracy and the appropriate
use of them (Case study: Interpolation of Precipitation in Fars province)
Abstract
In many scientific researches, error measurement statistics are often used without taking notices into account
when selecting a model or method for the spatial analysis of environmental hazards. In order to assess the
accuracy of precipitation interpolation methods in Fars province, the performance of widely used error
measurement statistics and some comments were implemented. Spatial interpolation of precipitation was
accomplished using inverse distance weighting, kriging, co-kriging, and radial basis functions methods with 161
weather stations (22 synoptic and 139 rain gauge stations) for 2018 as a rainy year. The results of MBE statistic
evaluation indicated that the researcher may have chosen the incorrect interpolation method in certain cases
where the sum of the positive and negative values became zero. In addition, this statistic is limited to indicating
overestimation or underestimation and should not be used for assessing accuracy or selecting interpolation
techniques. Regarding the coefficient of determination (r 2 ), the results revealed that due to the lack of
compatibility in the magnitude of the range of this coefficient (0 to 1) with error values (100 to 400 mm for the
interpolation of precipitation in Fars province), its use in evaluation of the accuracy of a method is not
recommended. In terms of NRMSE, the results showed that samples with a small number of observations (n=3),
its value increased excessively (NRMSE=0.35) when compared to samples with a bigger number of data (n=20,
NRMSE=0.097). Therefore, it is not advised to use this statistic. In conclusion, since MAE and RMSE statistics
provide a more realistic error value, it is advised to use them for assessing the accuracy of interpolation
methods.
Keywords: Precipitation, Error evaluation statistics, Interpolation methods, Fars province



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