Search published articles


Showing 192 results for Si

Mehran Maghsoudi, Elham Heidary,
Volume 10, Issue 4 (12-2023)
Abstract

Geological diversity has created a new branch of the tourism industry called geotourism , where geological and geomorphological features are explored . The main focus of geotourism on geological elements includes two items, form and process . There is a set of geological forms and processes in places , which are called geosites . This has given rise to a new branch of tourism called geotourism , which examines places that have the ability to attract tourists and management aspects that can help the local community for economic development. In the first stage , it is very important to know the abilities and characteristics of the studied area . Scientific, tourism and educational evaluation of geosites in the region is the basis for optimal exploitation and sustainable development. In recent years, more attention has been paid to the Garmsar region, which has led to the development of geotourism. The impact of tourists and mines that have been created by humans, the Tastkan caves that have changed the strength of the salt caves, and also the role of natural factors, have all led to the environment's reaction
Dr Ali Zangiabadi, Mr Fazllollah Karimi Ghotbabadi,
Volume 10, Issue 4 (12-2023)
Abstract

Economic resilience to natural disasters, which is actually how economic capacities affect disasters, is one of the issues that must be considered in any society. It is noteworthy that the type of attitude towards economic resilience and how to analyze it on the one hand, plays a key role in how to recognize the current situation resilience and its causes, and on the other hand also affects policies and measures to reduce risk and how to deal with it. The purpose of this study is to rank the economic resilience of new urban Habitations in the ​​Isfahan Metropolitan against earthquake risk. Due to the studied components and the nature of the subject, the approach of this research is "descriptive-analytical". The statistical population of this study includes 6 new urban Habitations of Shahin shahr, Majlesi, Sepahan shahr, Fooladshahr, Baharestan and Shahid Keshvari. This research is applied in terms of purpose and in the research literature section, information has been collected through the library method. According to the results obtained from ASI in this study, the new urban Habitations of Baharestan, Majlesi, Fooladshahr, Shahid Keshvari, Sepahan Shahr and Shahin Shahr have the first to sixth ranks in terms of economic resilience to earthquake risk, respectively. In order to reduce the adverse effects of earthquake risk, pay attention to the economic capacity of the studied Habitations and reduce the economic risk factors in each community, economic resilience should be considered to avoid financial losses caused by these possible accidents.
 
Mrs Ziba Yousefi, Dr Hossein Jahantigh, Dr Farhad Zolfaghari,
Volume 10, Issue 4 (12-2023)
Abstract

 Investigation and monitoring of desertification in arid and semi-arid regions is a major concern for societies and governments due to its increasing rate. It is essential to identify areas at risk of desertification to manage and control this phenomenon in the shortest possible time and at minimum cost. The objective of this study is to create a map of desertification intensity in the MoradAbad plain of Saravan using the Albedo-NDVI model, which is based on remote sensing. Two Albedo and NDVI indicators were extracted from Landsat 8 satellite images in Erdas Imaging software after necessary corrections. A linear regression was formed between the two indicators by selecting 200 pixels corresponding to each indicator. Based on the slope coefficient of the line obtained from linear regression, the equation for determining the intensity of desertification was obtained. A map of the intensity of desertification was prepared based on Jenks’ natural refractive index. To evaluate the accuracy of the model, a clutter matrix was formed between 100 corresponding points. The results of linear regression between NDVI and Albedo indices showed that these two indices have a high negative correlation with each other (R = -0.85). The results of the desertification severity classification based on this model showed that 35% of the area is in the very severe class and only 5% of the area is without degradation. The model’s accuracy value was obtained with a kappa coefficient equal to 0.58, indicating good accuracy of the model.
 
Dr Mohammad Rahmani, Dr ّfarhan Ahmadi Mirghaed, Dr Sareh Mollaaghajanzadeh,
Volume 11, Issue 1 (5-2024)
Abstract

This study aimed to assess the habitat quality of the Tajan watershed in northern Iran through land use changes from 1992 to 2052 and to investigate its relationship with landscape metrics, including number of patches (NP), patch density (PD), edge density (ED), largest patch index (LPI), landscape shape index (LSI), and splitting index (SPLIT). Landsat 8 and 4 images were processed to produce land use maps for 1992, 2022, and 2052 using maximum likelihood, cross-combination, and CA-Markov methods in ENVI and TerrSet software. Habitat quality was also assessed using InVEST in three scenarios based on the land use maps. Relationships were analyzed using least squares regression and Spearman's correlation test. The results showed that from 1992 to 2052, forest and agricultural areas had the most decreasing (-82,460 hectares) and increasing (76,392 hectares) changes, respectively. Habitats in the central part of the watershed had higher quality than those in the northern and southern parts. The relationship between habitat quality and land use changes is significant and inverse (-0.95
 

Dr Mehdi Safari Namivandi,
Volume 11, Issue 1 (5-2024)
Abstract

Geotourism is one of the important pillars of tourism, which plays an important role in the economic and social development of regions, and this issue is doubly important in border regions. Considering that one of the ways to create security in the border zone is the economic development of the region, therefore, the development of geotourism in the border zone of the country is important. Considering the importance of the issue, in this research, the effects of geotourism development in creating sustainable security in Marivan city have been analyzed. In this research, the 30-meter height digital model of SRTM, the results of interviews and library studies have been used as research data. The most important research tools are ArcGIS, Expert Choice and SPSS. Also, in this research, Comanescu models, AHP and SWOT model were used. According to the intended goals, this research has been carried out in several stages, in the first stage to identify and evaluate geosites, in the second stage to analyze the effects of geotourism development on the goals of sustainable development and regional security, and in the third stage to identify effective factors. The development of geotourism has been discussed. The evaluation results of the identified geosites based on the Comanescu model have shown that the geosites of Marivan city have a high potential for the development of geotourism, which can be paid attention to with economic development, environmental development, infrastructure development and finally, it should be associated with the stable security of the region. Also, the results of the SWOT model have shown that the existence of rare geosites with a weight of 0.08, the lack of long-term development plans with a weight of 0.08, the creation of stable security in the region with a weight of 0.091, and the seasonality of employment with Weight 0.058, respectively, are considered as the most important strengths, weaknesses, opportunities and threats of geotourism development in Marivan city.
 

Khabat Derafshi,
Volume 11, Issue 1 (5-2024)
Abstract

Coastal areas are constantly changing physically and ecologically, depending on natural and human factors. The natural causes of coastline changes are assessed in three ways: short-term changes including the effects of up and down currents, long-term changes including climate change, periodic storms and waves, and accidental changes including sudden natural events. Today, coastal tourism is considered as one of the important factors in the development of coastal areas. In this regard, the Caspian Sea, with many tourist attractions such as lush forests, accessible foothills and mountains, historical monuments and appropriate welfare facilities, benefits from the sea and beaches. The coastal area of Babolsar City, due to its many facilities and capabilities to attract tourists, much of which is due to natural and environmental attractions, every year, hosts a large number of tourists who come to this area to take advantage of its facilities and attractions, including the beautiful beach and very beautiful forests. This coastal area because its dynamic nature, is exposed to permanent erosion and variability due to processes such as river, wind, tectonic, wave and tide and marine transgression-regression in the area causes the destruction of coastal facilities and recreational places. Therefore, any planning to change the land use and construction in this coastal area should be considered in terms of the sea water fluctuation impacts on the shoreline position. Coastal environmental degradation as a result of Caspian Sea water level fluctuation are very probable and human behaviors in non-optimal choice of the land use locate intensify these losses. Coastal tourism, as one of the coastal land uses is heavily influenced by fluctuations in sea level in both marine transgression-regression statuses.
 
Fahimeh Pourfarrashzadeh, Fariba Beyghipour Motlagh, Mortaza Gharachorlu,
Volume 11, Issue 1 (5-2024)
Abstract

This study aimed to systematically explain the potential of the landslide occurrence to provide a prediction model of the possibility of this phenomenon in the Yamchi catchment in Ardebil province. In this regard, both approaches of discrete and continuous variables were used by means of overlay and logistic regression, respectively. Independent variables included elevation, slope, aspect, lithology, annual rainfall, roughness, general curvature, topographic wetness index, vegetation index, distance to fault, distance to stream and distance to road. The results, firstly, revealed the areas with high landslide potential by the matching layers of independent variables with the landslide layer in the geographical information system (GIS). These areas were in the middle elevation, high slopes, northern slope, high roughness, erodible formations, high rainfall, medium vegetation, surroundings of faults and rivers. Secondly, the results of the logistics regression model by providing a prediction equation of probability of landslide occurrence showed that the resulting model with pseudo r2 and ROC 0.22 and 0.86, respectively, had good power and efficiency to predict landslide through the catchment. In addition, the resulting beta coefficients for independent variables indicated that the importance of the variables was as follows: vegetation index distance to road, rain, lithology, distance to fault, elevation, topographic wetness index, roughness index, aspect, slope, and distance to river. In the end, the need to pay serious attention to the supporting and protection of vegetation cover of the mid -range and upstream of the catchment was determined because of unstable geomorphic conditions of these areas.
 
Dr Saeed Jahanbakhsh Asl, Dr Yagob Dinpashoh, Phd Student Asma Azadeh Garebagh,
Volume 11, Issue 2 (8-2024)
Abstract

Evapotranspiration is one of the main elements of hydrologic cycle. Accurate determination of reference crop potential evapotranspiration (ET0) is crucial in efficient use of water in irrigation practices. ET0 can be measured directly by lysimeters or estimated indirectly by many different empirical methods. Direct measurement is cumbersome, needs for more time and costly. Therefore, many investigators used empirical methods instead of direct measurements to estimate ET0. Nowadays, the FAO-56 Penman Monteith (PMF56) method is known a bench mark for comparing the other empirical methods. For example, in the works of Zare Abyaneh et al. (2016), Biazar et al. (2019), Dinpashoh et al. (2021) and Dinpashoh et al. (2011) PMF56 method was used to estimate ET0 and comparing the outputs of other empirical methods. Many researchers analyzed trends in ET0 time series in different sites around the Earth. Among them it can be referred to the works of Sabziparvar et al. (2008), Babamiri & Dinpashoh (2015), Dinpashoh et al. (2021), Dinpashoh  (2026) and Tabari et al. (2013). ET0 can be affected by many different climatic factors such as maximum air temperature (Tmax), minimum air temperature (Tmin), relative humidity (RH), wind speed, and actual sunshine hours. Factor analysis (FA) is a multivariate method that reduces data dimensionality. In general, climatic variables have high correlation with each other. On the other hand, these variables affect ET0. The FA can be used to reduce data dimensionality in which correlated variables converted to few uncorrelated factors.
 
Shamsollah Asgari, Kourosh Shirani,
Volume 11, Issue 2 (8-2024)
Abstract

Gully erosion is one of the advanced forms of soil erosion, which needs to be analyzed and identified in order to protect the soil. In this research, according to the complex system of factors influencing the creation of ditch erosion, 23 factors were analyzed in the two famous Dempster-Schiffer models and the entropy model, and using Google Earth images and field visits, 331 ditch points were identified, recorded, and a ditch distribution map was prepared. Spatial data of gully erosion distribution were divided into two random training (70%) and experimental (30%) groups. In this research, two indicators of tolerance coefficient and variance inflation factor were used to check the collinearity test, and as a result, two indicators of waterway density and relative humidity index were removed and 21 factors were used in the modeling process. The output results of the layers, weighting and classification and integration in two Dempster-Schiffer and entropy models are the extraction of the zoning map of the gully's erodibility sensitivity. and 30% of the calibration and validation of the models, the area under the ROC system performance characteristic curve and the area under the AUC diagram of the Dempster-Schiffer model with an explanation factor of 0.934 and the maximum entropy model with an explanation factor of 0.936, both models have an acceptable percentage of the area under the curve were that this issue shows the high performance of both models in the region. Among other results of statistical analysis, the prioritization of the impact of 21 factors in causing ditch erosion in the region was determined. The scientific results of the research can be promoted and taught, and from the practical point of view, the relevant executive body to control ditch erosion can take the necessary measures using the results of this research.
 
Mousa Kamanroudi Kojouri, Habibolah Fashi, Sgahla Barati Sadeh,
Volume 11, Issue 2 (8-2024)
Abstract

Developing roads and constructing new highway are urban policices contributing to solve transportation problems in cities. These projects often being passed through urban fabrics, so it is nessessery to buy and demolish buildings from their owners including individuals or governmental and public institutions to imply the projects. However, acquiring land is not an easy task and completing these projects may hit with long-term delays. This paper aimed to analyze the impacts of delaying in constructing Shoosh Highway in Tehran. The investigated impacts originate from land acquisition problems. The research data was obtained from many sources including documents and research reports, a survey, and interviews with Tehran Municipality managers. The One Sample T-Test in SPSS software was performed to analyze the data obtained form the survey. Findings indicate that the residents are often dissatisfied with the project because since the beginning of the project, social security decreased a lot and people are less likely to respect citizens' rights than before, recreational sites are often demolished, the value of residential buildings slowed down significantly, living costs incresed, and businesses were stagnant. In conclusion, if urban highways are not contributing to proper planning and site selection, they will disrupt the physical, social, and economic structures of urban neighborhoods and cause to many environmental problemes including air pollution. To avoid these adverse outcomes, it should be thought in advance about sufficient financial resources and possible practical methods to acquire land for projects. These consequences are reduced by studying and managing the risk of projects.
 
Kaveh Mohammadpour, , Gona Ahmadi,
Volume 11, Issue 2 (8-2024)
Abstract

Abstract
Dust storm is a complex process that it was affected by relation between earth-atmophere system and point of veiw climatologist and meteorologist that they assessing atmospheric and climatic change, in general of world veiw, monitoring from dust cover is a need structures.
The western region of Iran is the study area. The data used in this study are divided into two categories: ground-based observations in 27 synoptic stations extracted from the Iran’s Meteorological Organization during period (1998-2010) and satellite MODIS images during the first to fourth days of July 2008. Finally, the aim has analyzed using Arc GIS and ENVI softwares and NDDI index.
According to results, interpolated map for the number of dusty days during the study period over the western half of Iran showed that extent of case study have not a equal system aspect quantity of occuring from dust phenomenon and how is it trend. The number of dust days increase from north toward south and sites located in northen proprotion of studied area have experienced a lower dust events. While, maximum hotspots are occuring over southwestern sites such as: Ahvaz, Ilam, Boushehr and Shiraz. Therefore, principle offspring of dust input has been out of country boundaries and arrived far way area. On based resultes obtined on satellite images using NDDI index also idicate that maximun of intense cover dust is observed over Fars, Ilam, Boushehr and Ahvaz provinces on the first, second, thrid and forth of July. But, the lowest rate of index situated in extent far such as: Eastern Azarbayjan, Western Azarbayjan provinces. Thus, parts located on the north of the study area experienced less dusty days and the maximum dust core was located in the southwestern (mostly ahvaz). The long-term result was consistent with the use of NDDI index and the daily average of NDDI index in the whole study area indicated the hotspot areas (Ilam, Ahvaz, Omidieh, Bushehr and Shiraz) during the first to fourth days July 2008. However, in the region has reduced the level of dust cover when a wet and cloudy synoptic system pass over the central and northwestern parts of the study area.
Mrs Samaneh Riahi, Dr Amir Safari, Dr Seyed Musa Hisseini, Dr Ali Ahmadabadi,
Volume 11, Issue 2 (8-2024)
Abstract

In order to plan, manage and exploit water and land resources, awareness of the spatial variability of resources, as well as understanding the response behavior of the watershed in order to model physical processes, has an identical significant role. Due to its location in arid and semi-arid areas, special climatic and geomorphological conditions, Qom-Roud basin is prone to flash floods. Due to the lack of hydrometric and topographical data with high accuracy in the basin, the use of hydraulic models does not lead to accurate results of the hydraulic characteristics of floods. In such a situation, the methods based on the geomorphological features of the basin can be advantageous. In this article, Variable flood stage method (VFS) method is used, which combines the hydraulic characteristics of the river with the geomorphic characteristics of the basin in order to estimate the water depth in the river caused by floods with different return periods. The water depth was investigated for different return periods of two, five, ten, twenty-five, fifty and hundred years. In each period, the highest water depth was in the parts near the outlet and the lowest water depth was in the upstream parts of the river. The research illustrations there is a direct relationship between the depth of water and the area of the sub-basin. The results of this research can be used for basins without hydrometric and topographic statistics with high accuracy in order to estimate the peak speed and flood depth.
 

Page 10 from 10     

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

Designed & Developed by : Yektaweb