مجله مخاطرات محیط طبیعی
پیاپی 20 (تابستان 1398)

Dust is one of the important processes of arid and semiarid regions that its occurrence has increased in recent years in Iran. Identifying the dust and sand sources, it is the first step in the management and control of this phenomenon. Because of the arid and semiarid climates where dust phenomenon takes place, always there are large areas to monitor and control that practically makes it impossible to manage them. Therefore, reduce the candidate regions to actual sources is one of the main concerns of the researchers. In this paper, identification of potential dust sources using remotely sensed data has been studied. Various spectral indices of moisture and vegetation were applied on the OLI sensor data and finally, wetness spectral index of Tasseled Cap Transformation and DVI vegetation index were selected based on their variation in the study area and was applied on satellite images from 2013 to 2015 and credibility potential maps of moisture and vegetation was produced. Roughness index was applied on the ASTER digital elevation model and credibility potential map of roughness was produced. Erosion sensitivity map of rocks was produced using geological maps. Potential dust sources map was prepared with a combination of credibility potential maps in multi- criteria evaluation model and validate using field based and these areas were visited based on stratified random sampling scheme. Results showed that as well can be identified potential dust sources using satellite images and determining to apply various indices.

The soil is one of the most important factors of production that has a great influence on human economic and social life. The surface of the earth is generally covered by soil and other surface deposits. Soil erosion is one of the most important problems and problems we face today. Increasing exploitation and lack of proper human management of the natural environment have a great effect on the intensification of soil degradation and erosion processes. In this research, the effective parameters analysis of erosion and sediment production in Dakehah basin with a total area of 9923.2 ha in southern Kerman province was studied using the Revised Universal Soil Erosion Model (RUSLE). Data and tools used in the research include data from meteorological stations, digital elevation model (DEM), ETM 2015 satellite imagery, GIS and remote sensing (RS) It should be. By studying the effective factors in this model, which includes rainfall erosivity factor, soil erodibility factor, topographic factor, and vegetation, the purpose of this study is to estimate the annual soil erosion in the study area. The erosion rate of the basin is estimated. Accordingly, annual soil erosion in the whole study area is estimated at 67 tons per hectare per year. The results of this study show that the highest effect on the estimation of erosion, a topographic factor with the highest coefficient of explanation was 92.6 In this research, the effectiveness of RUSLE technologies of annual soil erosion is confirmed by the new model of GIS and remote sensing for quantitative estimation of soil erosion values.

Considering topographic limitations of Sanandaj, the trend of spreading residential areas to hazardous areas has increased in recent years. In this regard, in the present study, the trend of the expansion of residential areas in the urban area of Sanandaj in the years 1991 to 2015 has been evaluated. The methodology is in such a way that after preparing satellite images (Landsat 5, 7, and 8) of 1991, 2000, 2007, and 2015 and preprocessing the images, land-use classification map have been prepared in four classes of residential areas, agricultural lands, gardens and rangelands for each of these years. Then, the analysis of the changes has been performed in each of the uses over the years. For this purpose, the Land Change Modeler model has been used. The results of the research indicate that each year about 1/1 km2 is added to the residential areas of the Sanandaj urban area, so that in 1991 the total urban area of Sanandaj city was 27.2 km2, while in 2015 this figure reached 54.5 km2. Then, the layer of prohibited areas in terms of geomorphologic parameters has been prepared in the ArcGIS environment. After preparing the layer of prohibited areas (Height above 2000 m, northern aspects, slopes above 30%, 1000 m of the fault zone and 200 m to riparian zone), the expansion of residential areas in the years 1991, 2000, 2007, and 2015 in prohibited areas has been evaluated. The results of the calculations indicate that, in 1991, about 7.8 km of residential areas were located in prohibited areas, which increased by 14.8 km2 in 2015. These areas are mainly located in the western part of the Sanandaj city located at Abidar highlands and in the steep areas, as well as in the eastern part of the Sanandaj area located on the riverside.

Groundwater resources are considered very important, particularly in the arid and semi-arid regions. Evaluating the vulnerability potential of these resources for conserving and preventing them from being polluted is included as the environmental organizations' priorities. Ajabshir plain is located in East Azerbaijan Province and northwest of Iran. The present study has been conducted to prepare intrinsic vulnerability maps in the aquifer of Ajabshir plain using DRASTIC and GODS methods. In DRASTIC model 7 factors including depth to water, net recharge, aquifer media, soil media, topography, the impact of vadose zone and hydraulic conductivity are used. Four factors including aquifer type, vadose zone, depth of the groundwater, and soil media are also used in GODS model. Providing, ranking, and weighting of the layers in each model have been done in ArcGIS software. Then vulnerability maps have been provided through overlaying these layers. In the DRASTIC model, the study area has been classified into four classes, including very low (13.48%), low (55.43%), moderate to low (28.69%), and moderate to high (3.08%). The study area has also been classified into three classes, including low (43.36%), moderate (52.42%), and high (4.21%) by GODS model. Generally, the vulnerability has been evaluated low and moderate in a massive area of the aquifer while a very small part of the study area has been recognized as the most vulnerable area through both models.

Population enhancement and consequently increasing of land use changes and excessive exploitation of ground water resources, not only has reduced the quantity of groundwater resources but also has degraded the quality of these resources. The study and investigation of groundwater resources quality can lead to the correct management of these resources. So the purpose of this study was investigation of the effect of land use changes process on groundwater resources quality and also comparison of different Geostatistical methods for water quality zoning in terms of EC and SAR parameters for agriculture and irrigation using Wilcox method. For this aim Landsat satellite images of the TM 2000 and OLI 2014 sensors using Maximum Likelihood Method was used. Wilcox method was used for determining the quality of groundwater resources in terms of EC and SAR parameters. Also, RMSE and R criteria were used in order to compare symmetry of fitted models to data. The results showed that Simple Kriging method with Circular Variogram Model and the amount of RMSE equal to 1782.19 and R equal to 0.81232 was the best method for EC and Ordinary Kriging Method with Gaussian Variogram Model and the amount of RMSE equal to 3.29534 and R equal to 0.79791 was the best method for SAR in terms of groundwater quality zoning. The conclusion showed that an increase of the area of urban and agricultural uses and also 13% increase in groundwater destruction have happened in study area which the most important causes were excessive exploitation and using organic fertilizer. Generally, due to the increasing of the area of urban and agricultural uses, an increase of 2% of pollution in terms of EC and an increase of 5.5% of pollution in terms of SAR has occurred in groundwater resources.

In urban areas, due to the development of the impermeable area, and consequently increased runoff production capacity, The risk of flood damage is more serious than other areas. The first step in the management of urban floods is identifying critical areas. In this research, the PROMETHEE II technique is used to prioritize the sub-basins of Urmia prone to flooding. For this purpose, the boundary layers of the hydrological units were determined using ArcGIS technique based on the slope of the area and the condition of the water conduits and joints. 22 subshells were determined. Physiographic characteristics of sub-basins (runoff depth, imperviousness, elevation, curve number, main channel length, form, perimeter, and area) were selected as ranking criteria. The weight of these variables should greatly affect the sub-basins ranking process and needs to determine with a specific precision. The effect of these variables is also varied in a different region. In this research, the weighting of the criteria was performed using both of the hierarchical analysis method (AHP) and analysis of the main components (PCA). In each sub-basins, the PROMETHEE II technique was applied for weighting methods, and sub-basins were prioritized and compared. The results showed that the priority of the sub-basins differed according to the weighting methods. When two methods of weighing were applied, only two of seven sub-basin have the same priority.The first criteria were runoff depth, and its weight was different for PCA and AHP methods (0.150 and 0.280 respectively). The effect of the difference in the weight of the criteria and their priority in flooding was significant. Among the first seven sub-catchments, there are only four common sub-catchments and, among these four sub-catchments, only two of them had the same ranks. This shows that the PCA method is more accurate in weighing the criteria due to the consideration of the spatial characteristics of the criteria and elimination of the error in the survey based methods.

The occurrence of the flood is considered as one of the most important environmental hazards with high impact in urban areas that threatens the environment, human beings, and human assets permanently. In this research, using AHP model, fuzzy logic and its integration with GIS, the flood phenomenon in Lamerd city in the south of Fars province has been analyzed. For micro-zoning flood hazard, eight important criteria such as natural criteria (distance from the waterways, geology, and slope) and human criteria (road network, urban bridges, residential, agricultural and forest uses, land suitability) have been used. The results show that the flood-hazard area stretches in a broad strip along the northwest-southeast and covers most of Lamerd's urban area. This zone starts from the Zanganeh and Niraiee areas in the northwest of the Lamerd suburbs and includes Mohr -Lamerd highways, Ahmedabad and Ziarat areas. This area stretches along Motahari Street, Jomhuori Street and Moallem boulevard to the south end of the city of Lamerd. Therefore, an important part of Lamerd city and its suburbs are prone to flood hazard and at least half of the city is in a warning condition and the conditions of flooding is very possible.

Population growth and increasing use of water resources for agriculture, industry, and sanitary sectors are the main causes of water degradation and groundwater pollution. Due to over-extraction of groundwater resources in the fertile plain of Borujen in recent years, this region has been recognized as a prohibitive plain. The main objective of this study is investigation of groundwater quality in Borujen plain aquifer using Algebraic analysis and Geostatistical methods. In this regard, the data from 19 sampling wells were used to study the groundwater quality of Borujen Plain during the period of 1989-2013. Spatial variations of water quality parameters were evaluated using algebraic methods (IDW and RBF) and Kriging. The ME and RMSE statistical measures were used to evaluate the spatial interpolation results using cross validation method, and the appropriate method was selected for zoning the different ground water quality parameters. The results of spatial interpolation of groundwater quality parameters showed that the Kriging method was the appropriate approach (RMSE = 30.72 and ME = 0.09) to estimate the Total Hardness parameter (TH) in the Borujen Plain. Also, the pH, SAR, Cl and SO4 parameters are well estimated using the RBF method with RMSE, ME of 0.05, 0.33, 0.27 and 0.4. While the IDW recognized as the best interpolation method for EC and TDS parameter with 84.62 and 56.36 RMSE values. In conclusion, the comparison of prepared maps of TH, EC, Chlorine ion concentration, Sulfate ion concentration and SAR, parameters showed a similar pattern and the minimum and maximum values of all parameters is located in in the common areas of the area under study.

Basically, the earthquake is one of the natural disasters that have devastating effects on human settlements, causing heavy casualties and deaths on their inhabitants. At the same time, the physical vulnerability of the city has a direct impact on human-induced casualties. Usually, the vulnerability is aggravated by uncontrolled construction in faults, non-observance of standards and standards, inappropriate distribution of population and facilities in the city. An analysis of how to resist threats and mitigate their effects, based on the results, will be necessary to explain the relationship between physical and organizational resilience to this natural hazard. Now, the present study has been carried out to assess the level of urban blocks in Piranshahr. The research method is descriptive-analytical, using ANP model and GIS (Geographical Information System (GIS)), a scientific estimation of the city's resilience using spatial and non-spatial data. The results of the analysis show that 27% of the city's area has low and very low resilience, 56% moderate resilience and 17% high resilience. Hence, in the spatial dimension of the city, residential buildings and other physical elements located in old urban areas of the old age (parts of the south, west and east of the city) are more vulnerable than the newly built neighborhoods of the city (north and northeast of the city), which management Urban and national and regional planners can exploit these findings to make good use of urban regeneration.

Contamination of soil with pathological and carcinogenic toxic elements presents a vitally important challenge for the environment. The dispersed contamination source is one of the important pollution sources, which different elements originate from weathering of rock and alterations zones and diffuse in the environment. The mine lands are considered as one of the dispersed contamination sources. In these locations, excavation, concentration and uncovering of some elements cause contamination of soil, which leads to contamination of the environment. This paper presents the pollution load of toxic elements in 236 soil samples collected around mining zone in north of Meshginshahr, northwest of Iran. Pollution intensity of the soils was calculated based on the pollution index and enrichment factor. Classification of the soils was done by using the factorial and cluster analysis. Soil samples collected in this study contain higher concentrations of harmful elements compared to the target and intervention limits set by international regulatory standards. Concentration of elements such as As (3-3430mg/kg), Mo (0.5-160mg/kg), Sb (0.21-97.6mg/kg), Pb (3.7-518mg/kg), Cu (10-748mg/kg) and Sn (0.5-11.4mg/kg) was found to be very high in the region soils. Some of the soil samples also have a worrying levels of Cr (3-267mg/kg), Mn (27-4120mg/kg) and Co (0.5-211mg/kg) concentrations. As per the pollution index, 19.4-66.7% of the soils on the mineralized and altered zones in the region are considered as contaminated with toxic elements. There is a high variation of concentration of elements in the soil samples. Distribution of the elements have been influenced heavily by both chemical (pH, organic carbon content (%), concentration of Fe + Mn, Al and S) and physical (grain size < 63µm) factors. Emphasis need to be put on control measures of pollution and remediation techniques in the study area.

The main purpose of the present study is to assess the relationship between environmental vulnerability and infrastructure resilience of rural communities (in Bojnourd County), so that one can improve the resilience capacity in rural areas. The research was conducted in a descriptive-analytical method and in nature it is applicable in local planning and rural development systems. Research variables have been selected after reviewing theoretical foundations and literature on vulnerability and resilience assessment in Iran and other countries. Accordingly, two general indicators of vulnerability assessment and infrastructure resilience of rural communities were developed using 26 criteria in FAHP and fuzzy logic (Gamma operator with the thresholds of 0.7, 0.8 and 0.9) in the GIS environment. The results indicate that approximately 56.69% of the County’s area has a high and very high environmental vulnerability, and 47 villages were situated in this area. The survey of the resilience index indicates that there is a significant and direct relationship between low resilience in rural areas and environmental vulnerabilities in the eastern, southern and northeastern parts of Bojnourd County. In addition, based on the FAHP output, about 31 percent of the rural areas of the county, and based on the output of fuzzy logic, about 53 percent of the rural areas of the county are in a very high resilience level). The analysis of the output results of FAHP and fuzzy logic in GIS with a Kappa coefficient of 0.166 showed that the results of the two models have comparatively weak but direct correlation, which was determined by measuring the accuracy of the models using ground control points. Fuzzy logic model with a Kappa coefficient of 0.772 is more accurate than the FAHP model with a Kappa coefficient of 0.550.

Probability of SDS Days Prediction in Iran’s Eastern Region Using Spatio-Temporal Indicator Kriging model AbstractOne of the most important environmental challenges in the Middle East and Iran in recent years is the increasing SDS phenomenon. In order to forecast the probability of SDS days, wind speed and Horizontal view data in the eastern regions of Iran was investigated using Kriging model of Spatial-Temporal indicator,and R software, in which indicators one and zero were considered for a SDS and for a day without SDS, respectively. Then the SP Data array (Spatial Temporal Data) was constructed with a combination of the matrix and vector in the STFDF class (Spatial Temporal Function Data Frame), and STF class (Spatial Temporal Function). After fitting all the separable and non-separable models, the sum metric variogram with the least average of sum of squares was selected as the best model for fitting data. The output of the model showed that the data enjoy a spatial-temporal dependence to 5 days, so from the last day of the statistical period we can forecast the probability of occurrence of the SDS day for the next 5 days. On the first forecast able day, i.e. 2017/04/01, the critical points of Sarakhs and Fariman stations in Razavi Khorasan province with a probability of 16 and 20 percent, respectively, Zabol, Zahak, Mirjawa, Nosrat Abad, Zahedan and Khash stations in Sistan and Baluchestan provice with 17, 13.13, 19.24 and 17 percent, respectively, and finally Abarkuh, Bafgh and Behabad stations in Yazd province with 20, 16 and 35 percent, respectively, enjoyed the highest probability of occurrence of SDS days. Keywords:Spatial-Temporal Variogram, Predict, SDS Days, Eastern Rregions of Iran, Kriging Indicator, Sand and Dust Storm(SDS), Region, Indicator Kriging Method, SDS.

Changes the Sea surface temperature and lake can have significant impacts on marine ecosystems and the lives of human societies on the edges of these seas. By trend analyzing the temperature of sea surface temperatures, we can examine the extent of its impact on global climate change. Given the fact that the Caspian Sea is known as the world's largest closed water body, these changes in surface water temperatures can cause great damage to the sensitive and fragile ecosystem of this sea. The purpose of the present research is to analyze the trend of sea surface temperature in the Caspian Sea in order to investigate the effect of this sea on global climate change in order to apply it in management plans to maintain the balance of this valuable water ecosystem. This research was performed using non-parametric statistical methods on 720 cells using network data with a spatial resolution of 0.25 * 0.25 * arcs in a 29-year statistical period. The results of the study showed that the monthly, seasonal and annual monthly water temperature of the Caspian Sea has a significant upward trend, which requires the attention of planners and decision makers in the margins of this sea to maintain ecosystem balance. Considering that the Caspian Sea is a closed system, any appreciable increase in surface water temperature can have adverse effects on aquatic life, water resources, evaporation from the sea level and, consequently, on the level and status of pollution of the sea.

Compost is one of the urban waste management strategies that aim to reduce the volume and weight of materials to be repelled, reduce the spread of flue and fat, recycle resources, and reduce the cost of disposal. In order to comply with environmental laws and regulations in the framework of adaptation of an environmental development plan, an Environment Impact Assessment (EIA) plan for compost plants required. Accordingly, Leopold‘s checklist and modified matrix methods have been used in the environmental assessment of the Zahedan composting plant. according to the information obtained, it was determined that the area is not inhabited and in other respects, due to the researches and land use maps, no specific ecological and socioeconomic complications are identified within 10 km of the plan, and the land of the plot is mostly muddy and rough. The only factor that can specifically increase the radius of the effect of the plan is the direction and amount of 120-day winds of the province, which is usually from Zabol to Zahedan, which, due to the appropriate distance to the site, does not affect the city‘s residents. In total, the option of doing a design with +0.94 versus non-performing option with -3.7 has a full advantage and the plan is strongly recommended for improvement plans and corrective actions. Based on the review of the long-term effects of the project in the exploitation phase on leachate and its leakage, the health hazards of the factory for the employees and the external environment (mainly from insidious insects and animals), smell pollution and contamination of the product.

Spatial analysis is an approach methodological that reimburse how mutual relations rooting differences, similarities of phenomena and events within the framework geographic views. Spatial analysis can lead to a new theory through review how to change phenomena to discover locative order of it. Resilience is the system capacity upgrade for retrieval and ability, adaptation and tolerance with existing conditions after the events. It will come irreparable damage on the various dimensions of the social, economic life of societies, providing in the absence of resilient urban spaces and lack of prediction and readiness. The purpose of this study in order to achieving an appropriate solution with analysis of resilience in the social, economic, institutional and physical–substructure dimension in ten regions of Tabriz. The population of the study is urban experts in Tabriz regions were chosen based on the Cochran model module obtained by random sampling. This study has been done using quantitative methods with Spas software (Levene) and exploratory – descriptive type. According to the finding of the study, there are significant differences between the mean of these areas and the obtained value of F (2.3) and the significant level (0.028) with a degree of freedom (60.6) at the level of 0.05. District 9 with the highest average (64) has high resilience and the four and seven regions with the mean (50.28 and 49.85) have the least resilience. Therefore, city managers will prioritize policies and planning appropriately to promote less resilient areas, due to different resilience in different areas.