tayebeh mesbahzadeh

Long-term warming of the atmosphere, decrease in precipitation, drought and floods lead to the creation of climate change phenomena in natural and unnatural ecosystems. In addition, an increase in greenhouse gases, which cause the temperature to rise, also increases this phenomenon. Climate change affects different aspects of Mashhad city in terms of geographical location, tourism and tourism. In this study, using the CanESM2 model and the precipitation and temperature data of Mashhad station from 1961 to 2005, they were predicted in the near future from 2030 to 2060 and from 2070 to 2100 under RCP climate change scenarios. The results showed that the CanEMS2 model is in good agreement with the observational data and can be used to simulate the data in the future period. The simulation results show that the amount of precipitation will decrease in the near future, but not in the distant future. This parameter will also increase, but the temperature will increase in the future (near and far) and the phenomenon of global warming will increase. The results of this research can be used for environmental management and the services and industries that will lead to an increase in greenhouse gas emissions in Mashhad city can be used for proper policy and planning in order to reduce greenhouse gas emissions.

Dust storm is a phenomenon that occurs in arid and semi-arid regions due to high wind speed and turbulence on the surface of the soil without cover and prone to erosion. Dust changes the radiant budget of the earth's surface and changes the temperature of the earth's surface and atmosphere. Therefore, dust affects the energy exchange between the surface and the atmosphere as well as the dynamics of the atmosphere. Recognizing and studying the trend of dust storms and their relationship with climate change is one of the most important ways to reduce the damage caused by this phenomenon. This study amies to evaluate the effect of dust storms on radiation indices and heat flux according to the combination of satellite remote sensing information and re-analysis data in Hirmand basin.

In this research ERA5 re-analysis and Terra satellite data used for the August 23-26, 2010 event in Hirmand. Products and satellite data used including true color images and AOD and re-analysis data including Surface latent heat flux (SLHF), Surface Sensible Heat Flux (SSHF), Surface net Solar Radiation (SSR), Surface net Thermal Radiation (STR) and Balance Radiation (Rn). Dust particles were routed using the HYSPLIT model and wind speed in the study area was also assessed using the analysis data. Also, for validation of satellite data and re-analysis, visibility and air temperature data, at height of 2 meters, at Zabol Meteorological Station, closest station to the study area, were analyzed.

According to the HYSPLIT model output, most of the dust particles were collected from the deserts of Turkmenistan and then the dry areas around Lake Hamun and parts of northern Pakistan. AOD values showed that from August 21, the value of this index gradually increased so that on the 25th day, the maximum AOD value reached 1.25. Examination of the values of radiation and heat flux indices showed a significant decrease in SSHF, SSR, STR and Rn indices and their values reached the lowest value on the 26th day and the SLHF index with a slight difference on the 25th day reached its lowest value of 58 w/m2. Correlation study showed that SSR and Rn indices with -0.370 and -0.359 respectively had the highest and SLHF index with -0.153 showed the lowest correlation with AOD index.

The results of this study showed that the western parts of Hirmand Basin, Lavar or North wind has emitted dust particles into atmosphere, and the region and rotational currents has caused the distribution of these particles in the study area. The results of satellite data and their re-analysis and matching with real images showed that the study event increased the optical depth of dust particles, which resulted in tangible and surface heat fluxes, solar and thermal radiation, as well as balance. Radiation was greatly reduced. Evaluation of horizontal visibility and air temperature data at a height of 2 meters at Zabol station also confirmed the results of satellite images and re-analysis data.

Desertification is one of the destructive phenomena in the human court that causes the destruction of natural resources. Since Iran is located on a dry and semi-arid belt, recognizing the phenomenon of desertification and the factors affecting its intensification in our country is very important. In this research, satellite image information was used to study the role of land use change on desertification phenomena in the study area in northern Khuzestan. In a 24-year statistical period, a desertification intensity map was prepared using the IMDPA model based on water, climate, vegetation and soil criteria. The land use map of the area was prepared for three periods of 1991, 2003 and 2015, including six landuses: agriculture, rang land, salt land, flaggy and river. The results of the desertification intensity map showed that the intensity of desertification was initially in the period from 1991 to 2003, so that in 1991, about 9.6% of the region was in the low desertification class and 90.4% of the region was in the middle deserification class. In addition, since 2003, severe desertification class has been observed, which includes 8.3% of the region, and low and medium classes have covered about 8.7% and 87.4% of the region, respectively. Moreover, in 2015, low, medium and severe classes include about 14.8, 85 and 0.1 percent of the total area, respectively. In addition, the numerical value of the intensity of desertification in each use and its comparison showed that the most effective effect was the use of pastures, agriculture and residential areas, respectively, and the least effect was the use of Nizar in desertification of the region. To better examine the relationship between desert risk indicators and land use change, different models were adapted to the obtained data, and among these models, the best model was used for each use and intensity of desertification. Among the various uses, according to the correlation coefficient, the best relationship between desertification intensity and land use change was the use of salt land with 0.29 = 96.

Climate change is now recognized as one of the key environmental challenges of the 21st century. Earth warming has been heightened by global warming along with falling rainfall. In this regard, by using statistical exponential downscaling models and climate change scenarios (A2 and B2), prediction of temperature and precipitation parameters in the southern region of Kerman province has been investigated. The results showed that the precipitation values ​​in the future period compared to baseline at Bam synoptic station increased by 7.32 and 8.46 mm, respectively, in scenario A2 and scenario B2. Also, the results showed that precipitation values ​​in the upcoming period compared to baseline at Bam synoptic station increased by 7.32 and 8.46 mm, respectively, in scenario A2 and scenario B2. On the other hand, at the synoptic station of Jiroft, the average season temperatures were in the scenario A2 (24.79, 8.88, 17.38, and -48.5), the temperature increase in the spring and summer and the decrease in the temperature in the fall and in winter, the values in the scenario B2 are (26.41, 10.8, 16.65, and 6.27), respectively, in the spring and summer and the fall in winter and autumn.

Today, dust is a major challenge for human societies. Dusts have a significant impact on the Earth's radiation budget, global biochemical cycles, soil formations, and chemical compounds in the atmosphere. This phenomenon can affect public health indicators. The Iranian Central Plateau is located in arid and semi-arid climates; it is more likely to face this phenomenon than other regions. Dust management and control depend on identifying critical hotspots and stabilizing the harvesting area. The aim of this study was to identify internal dust sources using the vertical dust flux parameter.

Kavir and Loot deserts cover a large area of the Iranian Central Plateau. In this study, the WRF-Chem model and GOCART and AFWA wind erosion schemas were used to identify dust springs. Emission fluxes were used to detect dust springs. In this regard, a severe storm was selected on 05/22/2018 by WRF-Chem model for simulation. In order to verify and select the best wind erosion schematic of the Iranian Central Plateau, the data of MERRA2 re-analysis database and surface dust concentration values ​​were used.

The results showed that the outputs of GOCART and AFWA schemas were different. The GOCART schemas identified three strong dust sources in the study area that were located in the Jazmourian Basin, the Loot Basin, and the Central Desert (Kavir Desert), but the AFWA schemas were able to identify only one weak source in the Loot area. The results showed that Loot Desert Center, south of Jazmourian Basin, as well as Dasht-e Kavir Desert Center (Central Desert) are known as internal dust sources. So that from one square meter of these areas, it is possible for 5800 micrograms of dust to rise into the atmosphere per second. Due to the fact that the storm lasted for 12 hours, about 2 tons and 505 kg of dust were transferred to the atmosphere from each hectare of internal dust springs. The results of the GOCART schema were more consistent with the three-hour time-series data of the MERRA2 re-analysis database and were selected as the best wind erosion schematic in the Iranian Central Plateau.

The results showed that the WRF-Chem model had a good ability to resemble the dust flux in the study area. The results of the GOCART and AFWA schemas were different. The AFWA model estimated the internal dust sources to be very weak. However, the GOCART model well detected internal dust sources.

Drought and dust are some of the atmospheric hazards that have affected the western and southwestern regions of the country for many years due to various factors. The recent droughts have had a significant impact on the emergence and intensification of dust. Therefore, studies related to it are considered important. In the current study, temporal and spatial fluctuations of meteorological drought and dust in Khuzestan province were examined on a monthly, seasonal and annual time scale. Drought estimation was possible using standard precipitation-evapotranspiration index (SPEI) and estimation of dust occurrence based on phenomenon codes 07 and 09 with a field of view of less than one kilometer. To ensure the adaptation of drought to the abundance of dust, a Pearson correlation was established between the two phenomena. The results of correlation showed a direct and significant relationship between meteorological drought and the number of dusty days in the province. The most correlation is in February, July, June, August, and May. The highest level of significance is attributed to the winter and summer and then spring. Cross-correlation also showed that the events of the dust simultaneously and one month later are more affected by the drought.

Soil quality is an essential indicator for sustainable land management that generally depends on soil physical, chemical and biological properties. Due to the multiplicity of soil properties, the number of variables is usually reduced to a minimum set by statistical methods, which reduces study time, decreases monitoring cost for sustainable use of agricultural lands. The aim of this study was to introduce the most effective soil characteristics of agricultural lands in Mohammadshahr plain, Karaj, to prevent the descending trend of soil quality.
In this study, four farms and orchards which were different in terms of crop type and irrigation system were selected and evaluated with Integrated Quality Index (IQI) and Nemero Quality Index (NQI). In both indicators, the characteristics affecting soil quality are combined in the form of a mathematical model and presented as a numerical quantity. For this purpose, first 12 soil profiles were described, followed by sampling from topsoil (surface layer) and sublayers (weighting average for the depths) and testing 17 soil characteristics affecting its quality. In the next step, both indicators were calculated using two different sets of soil properties. The first category, the Total Data Set (TDS), included all measured soil characteristics, and the second group, the Minimum Data Set (MDS), included the most important properties affecting soil quality. The Principle Component Analysis was implemented to select the MDS. Soil properties were scored to calculate IQI and NQI. For this purpose, a function was defined for each soil feature to standardize all scores between zero and one. Weighting various soil quality properties was also performed by calculating the common variance of the variables, which was obtained by factor analysis method.
Calculation of IQI and NQI indices showed that the topsoil samples were in grade III and sublayer samples belonged to grade IV with major limitations due to lack of profile development, organic carbon deficiency, salinity and high gravel. Four and six items out of 16 variables were identified effective for topsoil and sublayers, respectively. The IQI index based on TDS was more accurate and sensitive than the NQI index for soil quality assessment, as more features are considered for TDS. In the IQI index, both the weight of attributes and their scores are effective, while in the NQI index, only the attribute score is considered. On the other hand, the coefficient of determination between the TDS and MDS for topsoil and sublayer samples was 0.55 and 0.56% for IQI model, respectively, and 0.48 and 0.16% for NQI model, respectively. In other words, the determination coefficients showed the reliability of using the MDS instead of TDS in both IQI and NQI models. In the MDS, mean weight diameter (MWD) showed the highest effect on the surface layer and percentage of gravel had the greatest impact on the soil quality of the sublayer.
Although TDS took into account all soil properties and showed a slightly higher coefficient of determinations with both soil quality indicators, the MDS obtained similar results to the TDS with only about half of the properties. In the MDS, the features with an internal correlation is eliminated rendering it more cost effective. The results of this study assist decision-makers to choose better quality management and soil sustainability strategies while decreasing the monitoring cost.

Soil erosion is a widespread environmental problem threatening environmental sustainability. It is one of the significant factors in both water and wind erosion. Understanding the physical and chemical characteristics of lakes and wetlands sediments is essential to study sedimentology and erosion. Drying up the wetlands around the world is one of the worst experiences of human life that has had many adverse effects. Large wetlands are drying because of changes in water use patterns, due to land-use changes and water constraints due to climate changes.

Systematic random sampling was carried out from lake sediments. Then the texture of deposits was determined using triangle soil texture. The velocity and direction of the dominant and erosive winds were determined by drawing the wind and storm rose. Thirty-three soil samples were taken from the lake surface and the agricultural lands around the lake by random sampling from 0-30 cm depth, and the location of each sample was recorded using GPS. Sorting was done by dry sift technique. GR graph 3.0 software was used to determine sedimentological indices such as Median Diameter, Median, Kurtesis, and Skewness of the samples.According to Kazeroon synoptic station's wind data, the wind condition of the area was studied in the form of a wind rose. The erosion rate threshold of the lake surface sediments is needed to calculate the storm rose. For this purpose, wind data from the study area and sampling were used to determine the wind erosion threshold velocity, based on soil properties and experimental formula.

The soil texture results showed that the sand had the highest percentage of material degradation in all samples, and the average sand content of lake sediments was about 62%. Clay and silt are less abundant, respectively. Soil texture in the study area was almost similar to agricultural land and the lake area, only with slight changes in texture due to increasing treatment intervals. According to the soil chemical analysis results, the electrical conductivity of all samples taken from the study area was less than four dSm-1 indicating that the soil was ordinary. Soil sodium content was low, thereby increasing aggregate resistance to dissemination and making the soil more resistant. In all samples, saturated moisture content was more than 50%, having high moisture content, resulting in fine particle adhesion.Based on the Kazerun station results, the frequency numbers of distribution of the annual wind class show that 50.97% of the winds are calm, and 49% of the winds have direction and velocity. The direction of the prevailing wind is westward. The Kazerun station annual storm results (2006-2016) show that 99.8% of the winds are calm, and only 0.2% of the winds have direction and velocity. This value is not visible in the flowchart diagram of the storm rose, so they can be ignored.

Parishan Lake is one of several lakes in Iran that has dried up in recent years. In this study, we tried to show whether this event as a dust storm source, can be an environmental threat for residents living in urban and rural areas around the lake. The results showed that the sand had the highest percentage of material degradation in all samples. Therefore, due to the low abundance of silt particles in Parishan Lake's sediments, lake sediments cannot be considered a potential origin for Iran's dust storm. According to the samples taken from the Lake Surface and agricultural land, the calculated morphometric values showed that the particles have irregular Kurtesis and a high skewness towards coarse grains. The results of soil physical and chemical property analysis show that the soil is resistant to wind erosion. The important thing to conclude from the wind rose is that the prevailing winds of the region are located in the classes of velocities less than 3.5 m/s, which do not play a major role in generating dust storms, which are more abundant in the basin. The problem does not threaten the rural areas around the lake and the city of Kazerun in terms of dust. If the dust is observed a few days a year, it may be due to external sources.

The dust phenomenon is of particular importance because of its close association with public health. Many researchers are looking for ways to reduce the harmful effects of this phenomenon. To this end, having information about the nature of the spatial and temporal pattern of this phenomenon is of particular importance to all researchers. Dust is one of the natural hazards of the central Iranian plateau. In this study, statistical analysis was performed on a yearly and monthly basis in the period 2006 to 2018 using codes 06 and 07 obtained from 50 synoptic stations located in the study area. Also the spatial pattern of dust days with horizontal views less than 1000 m, 1000 to 1500 m and 1500 to 3000 m in the study area was plotted. The results also showed that Tabas synoptic stations with 661 days, Arak with 528 days and Zahedan with 511 days with 1500 to 3000 m horizontal view were more important in the study period. Also, the results of seasonal survey of dust days in the statistical period showed that spring with more than 42% had the highest occurrence of dust. The results showed that in the horizontal view of less than 1000 m, Zahedan station with 113 days and Tabas station with 91 days of dust had higher frequency. Meanwhile, Zahedan and Shahreza stations with 91 and 55 days of dust with a horizontal view of 1000 to 1500 meters also had the highest frequency of dust days in the study area. Monthly statistical analysis revealed that most of the dust events were recorded in June and May. The results of spatial variation of dust days showed that there is no regular spatial pattern due to the extent of the area but in general in all three classes of horizontal view the focus of this phenomenon is most of the southeastern part of the study area.

Land use change are the result of complex interactions between many processes. Many models have been developed in recent decades to understand these dynamics. The present study, using Landsat satellite images and applying the maximum probability classification algorithm, examined the land use pattern of Simine River basin in 2000, 2005, 2010 and 2017 and identifies the historical transformations of them. Finally, the various scenarios of land use change in 2040 will be examined using the latest version of the Dyna-CLUE land use model. The results of modeling indicate Dyna-CLUE model performance in analyzing and predicting future land use patterns at the basin level and its calibration and validation coefficients in 2005 and 2010 are 0.84 and 0.69, respectively. Analysis of land use changes between 2000 and 2017 has shown that the most change was the conversion of rangeland lands to irrigated lands; So that about 343 square kilometers of rangeland lands (equivalent to 13%) decreased and irrigated agricultural lands increased by about 127%. Also, the spatial arrangement of land use classes in 2040 in the form of three optimistic, pessimistic and the continuation of the previous trend scenarios and its outputs have shown that the future pattern of most land use classes in the region has not changed much compared to historical spatial patterns and shows a marginal spatial expansion. The results of this study can be used as an effective tool for environmental planners to manage the future infrastructure of the Simine River basin.

Dust phenomenon is one of the most common and destructive phenomena in the dry and desert regions of the world and Iran, which can have harmful effects on human life and the environment. Wind erosion and the removal and transport of soil particles by wind create dust. Controlling wind erosion will be effective when enough information is available on the factors affecting it. The results of the related studies show that wind erosion phenomenon is very complex and controls many factors. Soil characteristics influence the severity of wind erosion through its impact on its erosion. However, in most researches conducted on wind erosion throughout the world, the role of soil characteristics has been confirmed in wind erosion, but few studies have been conducted in Iran, and the Alborz province, which has been exposed to wind erosion and dust storms in recent years, has not been investigated in these studies. Considering the importance of the issue in this area, the present study was conducted to investigate the role and effect of soil characteristics on the wind erosion threshold velocity and the occurrence of dust phenomenon. In this study, the wind erosion threshold velocity was measured in normal conditions using desert wind tunnel device, and the physical, chemical and mechanical characteristics of the soil were also obtained after sampling in the laboratory and compared with the estimated threshold velocity. Also, using wind velocity data and velocity thresholds, wind rose and storm rose area of the area were drawn and examined. The characteristics of the soil samples examined with high-precision included limestone, sodium, phosphorus, calcium, magnesium, organic matter, nitrogen, humidity content, shear strength, compressive strength, EC, pH, and d.( In this study, using grading of the soil samples , a variable called d has been measured. This variable indicates the percentage of particles with diameters between 0.1 to 0.5 mm as the most sensitive particles for wind erosion in the collected samples.) The results of measuring the threshold velocity using a wind tunnel device showed that the minimum and maximum wind speed thresholds in the area were 7.5 m / s, and 9 m / s, respectively. The range of 7.5 to 9 m / s indicates the high sensitivity of the region to the wind erosion; this is while the width of these areas is also high and this could be a serious threat to the province of Alborz and its neighboring provinces. Studies of the wind rose and storm rose in the region showed that the dominant winds in the region are from the northwest. And more than half of the winds erupted in the area are erosive and have the ability to move particles of soil and create dust. The relationship between soil characteristics and threshold velocity was investigated using the stepwise regression test. The results showed that the most effective parameters on soil moisture threshold velocity included particle size, lime content and shear and pressure strength of the soil. That is, as the amount of lime in the soil increases, the adhesion of the particles and consequently the pressure and shear strength of the soil increase. Moreover, when the percentage of particles with a diameter of 0.1 to 0.5 mm in the soil increases, threshold velocity decreases. In this study, soil moisture has the highest effect on the threshold velocity and has a direct relation with the velocity of wind erosion. The percentage of sodium in the sampled soils was very high, and this caused the disintegration of soil particles and reduction in the wind erosion threshold velocity. The study showed that the risk of wind erosion and dust-fogging greatly threatens the Alborz province. The actual focal points for the production of dust constitute a vast area of the province. These areas, integrated into the central part of the Eshtehard plain and being bordered by the deserts of the Buinzahra plain in Qazvin province, have placed a wider field of dust in front of the wind and are regarded as a serious threat and would have harmful consequences in the provinces of Alborz, Tehran and other neighboring provinces. Therefore, it is necessary to take a special look at these areas in order to prevent the risks of this problem from being exacerbated in the first stage and to reduce the risks in the next stage.

Reducing or increasing the climate parameters such as temperature and rainfall as a result of the climate change process, causes a variety of droughts. In this study, the effect of climate change on meteorological drought in Yazd province is investigated. For this purpose, the drought time series were determined in two historical periods (1961-2005) and the future (2017-2100) by SPI and SPEI. Historical data from Yazd's synoptic station and future data were generated by the CanESM2 model under RCP scenarios. Drought characteristics such as severity, duration and frequency were extracted based on run theory in order to compare and evaluate the trend of drought changes. The results showed case study experiences more sever droughts in the future than historical period based on SPI under 3 RCP scenarios while based on SPEI index under RCP2.6 and RCP4.5, the drought characteristics will decrease in the future compared with historical period and under RCP8.5, the severity and duration of the drought will increase. The severity-frequency and duration-frequency curve showed that increasing the return period increases the severity and duration of drought.

Dust storms and intensive winds are natural events which occur all around the world in arid and semi-arid areas. In the present study, changes in dust events during studied months, seasons and years (2000-2013) for Ardestan synoptic station and their relationship with drought (drought calculation using SPI index) were evaluated.. For this purpose statistics of selected station utilized in 14-years period (2000-2013). Codes extraction related to dust event (06 and 07) and data analysis conducted using MATLAB software and in order to study the changes trend in monthly and annual time series, non-parametric test statistics were calculated and then their significance was evaluated at 95 and 99 percent levels. Results showed that May and spring had highest dust events number compared to other months and seasons. Also, results showed that there was direct relationship between dust event and drought and years having intensive drought resulted to more duct events. Results indicated that in Mann-Kendall procedure, of total 13 data series, annual data series and in San-Estimator method, August had positive significant trend at 1% probability level and in Sen-Estimator method, data series in April and June months had increasing trend at 5% confidence level. Results of spatial analysis of anemometer data using WRplot showed that direction of dominant winds are toward south.

Dust pollution is one of the most important environmental challenges in recent years in the Middle East and Iran. It is important to monitor and control the quality of dust particles in a wider range using the methods that are more cost effective and less costly. The present study aims to use numerical detection and analysis to determine the resources of dusts and the route over Iran and Isfahan province in May 2013. In this research, HYSPLIT, NAAPS, COAMPS models and MODIS images were used. The detection of dust was determined based on the characteristics of the brightness temperature in the infrared thermal range of the Modis sensor and the temperature thresholds for distinguishing this event from desert lands and clouds. The HYSPLIT model was used to track the movement path of dust particles. Based on the results obtained from image processing and model output, North of Saudi Arabia and Southwest – Northeast direction are respectively the origin and main route of dust entry to Isfahan. The results of HYSPLIT model were compared with the results of the COAMPS and NAAPS models for the optical dust depth and surface dust concentration and the mass flow rate. The detection of the MODIS satellite images also acknowledges the creation of dust and moving it towards the center of Iran and the province of Isfahan.

In this study, the dust phenomenon was studied at the station of Isfahan temporally and spatially. For this purpose, the data, the time and date of the observation, the direction and wind speed, and the current weather condition were prepared. After extraction of dust codes (06 and 07) and statistical analysis of the data related to this phenomenon, the annual and seasonal wind rose and storm rose of the station were mapped using WRplot & WDconvert software during the statistical period of 2013-2002. The results showed that there were 525 days of dust in the region, which was the most frequent in 2012 with 62 days. Also, in May and spring, the highest frequency of dust occurred. The study of wind rose and storm rose annually confirms the formation of wind tunnel on the western-eastern route. The annual dust rose, divided into two meteorological codes 06 and 07, indicates that winds with dust from the Midwest are involved in the transport of suspended particles and formation of local dusts. Seasonal storm rose show the impact of different atmospheric systems throughout the year on the formation of dust phenomena in the region better and more accurately. With the onset of the cold season, the winds with dust are increasing from the northern half to Isfahan and reach the maximum in the winter, but with the start of the hot season, and especially the summer season, it is more intense than east to Isfahan, and from the west almost reaches zero.

Land use has always been one of the most important indications of the adverse impact of mankind on their environment. It is an activity that human beings, through using natural resources, contribute to their socio-economic development and at the same time, alter the processes and structures within the environment. One of the most important sources that have been damaged during the past decades through land use change is water resources, especially groundwater. Considering the importance of groundwater resources in supplying drinking water and agriculture, qualitative monitoring and spatial and temporal distribution of the process of its changes are important issues in planning and managing water resources. Therefore, the present research investigates the effects of changing the use of groundwater quality in Kerman Plain. Material and Land maps of Landsat 5, 7 and 8 were used for land use mapping in Kerman Plain. These are TM (1987), ETM + (2002) and OLI (2017) sensors, respectively. Also, in order to investigate the process of qualitative changes of groundwater resources in Kerman Plain, statistical data and information of 2002 and 2017 were used. Then, the maps of quality parameters were mapped to the ArcGIS 9.3 environment. Afterward, these maps were zoned to agricultural classes using Wilcox classification and the critical and contaminated areas were identified. . Spatial zonation maps of groundwater parameters for agricultural purposes were plotted based on Wilcox method. Finally, by coating the SAR and EC layers with ArcGIS9.3 software, the water quality status of the region for agricultural use according to Wilcox classification in 1996 and 2014 the area of each group was calculated. Using satellite images of the studied area, it was divided into three user units. These units included residential areas, agricultural lands, and rangelands. The quality of agricultural water was obtained from a diagram called the Wilcox Diagram. Land use change showed that a decrease has occurred in the pasture user's class. In the course of 30 years, while 1.691 km2 of rangelands have been decreased, the area of agricultural land and residential areas has been increased. The increase was far more in residential areas than agricultural lands. According to the Wilcox classification, the EC and SAR parameters were increased during this period, but the trend of increase in the EC parameter was higher. For the EC parameter, almost the majority of the region had a high level of this element, which is more intense in the western parts of the region than in other regions and has been increasing over time. For the SAR element, studies have shown that the amount of this element was in the good class in all areas of the region in 2002, except for the western parts of the study area which were in the middle class in 2014.

Desertification is one of the major challenges of the 21st century. Destruction of water resources, degradation of soil, as well as degradation of vegetation is desertification symptoms. This challenge is not restricted to dry areas, but can be applied in all regions, especially dry, semi-arid, and humid areas. Destroy the affected environment. Therefore, knowledge of its severity can play a significant role in water resource management. In this study, the IMDPA model, which is native to Iran, has been used to predict the desertification of Kerman plain in terms of climate criterion in 1409. Study of climate criteria and its score in the study area is from three indicators of annual precipitation, SPI drought index and drought persistence index. Using predicted precipitation values ​​by LARS-WG model and IMDPA model, the annual precipitation index score was 3.8, the index of drought persistence index was 0.7 and the SPI index was estimated 3.5 points. In the GIS environment, all indicator mapping maps it was drawn up.
The results showed that the annual rainfall index is very severe in the desertification class, the index of drought persistence in the low desertification class, and the SPI drought index in the severe desertification class are located, and the geometric mean of these indicators and their synthesis intensity The desertification of the area on the horizon of 1409 is in severe class. The results of this study can help in the management of desertification processes in the region.

Changes in temporal and spatial patterns of droughts are always a pivotal element of water resource planning, and the necessary strategies for policy-making and integrated water resources management are considered based on this parameter. Drought is a phenomenon degrading the lands and sometimes causes irreparable damages. In this research, SPI and GRI indices were used to study the spatial and temporal patterns of meteorological and hydrological droughts in Bam Plain. The results of this study showed that the most severe meteorological drought and the most severe wet occurred in 2002 and 2014 in the study area, respectively. Also, the most severe hydrological wet (SHW) and the most severe hydrological drought (SHD) are related to 2002 and 2014, respectively. Meanwhile, the hydrological drought temporal pattern occurs with a one-year delay as compared with meteorological drought in the study area. According to the results of the spatial pattern analysis, the moderate and normal drought classes covered most of the region. In addition, as moving from east to west, the severity of drought is increased and wet periods are mostly observed in the northeast of the region.

The main parts of Iran have been countered in arid and hyper arid area that in result of especial environmental condition as low precipitation and vegetation density can be caused wind erosion, whereas wind erosion usually has a tiny destruction quantity than water erosion due to wide its activity. Because of not matching presented models by other countries with climate and edaphic condition of our country, empirical model of IRIFR.E. A was offered. In this model nine effective factors in sedimentation of wind erosion are studied and then sedimentation of wind erosion is determined for each working unites, sub basins and basins. In this study, the IRIFER.E. A empirical method used for investigation of wind erosion classes in Ala region of Semnan. To reach this goal, scores of determined working units in this region were measured according to nine factors affecting this method. With considering the results, the highest score obtained from working units of waterway and clay land with Kalootak included annual sedimentation about 4443.2 and 5212.6 tone/Km2 respectively. Therefor 2.5 %, 48.23 %, 19.98 % and 29.19 % of region have a minor erosion (very low), low erosion, medium erosion and high erosion respectively

Desertification and land degradation have created a defective cycle of environmental problems, and have intensified degradation trend. Economic-social challenges and political crisis are considered parts of the consequences of land degradation, which may increase the vulnerability of the affected societies. To strengthen the resilience of local communities to cope with any natural disaster, it is necessary to identify and prioritize the impact of these phenomena to solve them based on prioritization of these effects. The aim of this study was to evaluate and prioritize the social - economic impact with moderate desertification in the Nasrabad region from the perspective of local communities and the participation of the villagers in line with desertification. In this study, numerical taxonomy was used to prioritize socio-economic impacts of desertification. Using the Cochran formula and given the population of the study area (5579 Person), 80 samples were collected. In this study, due to the average wind erosion, the first rank was allocated to the spread of dust and environmental problems from the perspective of local communities. The people of the region, more than anyone else, have experienced and understood the ways of interacting with these fragile ecosystems over time. Therefore, these interaction methods should be considered as the key to solving the challenges of desertification or as the best and perhaps last chance to deal with it comprehensively.

Due to the functioning of the ecosystems to support life on Earth, they play an important role. In recent years, natural resources economists have been engaged in valuation and measuring the role of natural resources in providing human welfare. They had made considerable progress in valuation of natural environment and ecological services of ecosystems. This research studies people's willingness to participate in protecting and reviving Noush Abad desert area, using the conditional valuation and tow-dimensional, dual choice questionnaire. To estimate the willingness to pay, logit regression model was used based on the maximum likelihood method and the parameters of the model were estimated. The results suggest that age, shortage of water resources (tapping too much water), family income have significant positive effects whileagricultural activity, animal husbandry, poor management and number of family members have a significant negative effect on the people's willingness to pay. Also, the factors such as age, education had positive impact while grazing has a negative impact on people's willingness to pay, but these variables were not significant at the appropriate level.The average willingness to pay of the deontologist and consequentialist people in this study to participate in protecting and reviving the deserts of Noush Abad is estimated to be 100000 and 99720 Rials, respectively.

Groundwater is a major source of water for domestic, industrial, and agricultural sectors in many countries. The main objective of this research was to provide an overview of present groundwater quality using parameters such as calcium, magnesium, sodium, chloride, sulfate, pH, and electrical conductivity (EC) in the Mehran plain, Ilam province using GIS and geostatistical techniques. A total of 23 deep and semi-profound wells were selected based on the classified randomized sampling method. The sampling locations were obtained by GPS. Plastic containers were used for the collection of water samples. These samples were transferred to the laboratory for analyzing water quality parameters. Statistical characteristics, qualitative data interpolation, and zoning were investigated using SPSS 20، GS+5. 3 and ArcGIS10. 1. Kolmogorov–Smirnov test were used to test data normality. In order to normalize parameters, logarithm, and 1/x were used for sulfate, EC, cation, and anion. Then the variogram analysis was performed to select the appropriate model. Results showed that co-kriging is the best method for cation and anion, whereas local polynomial interpolation is suitable for sulfate. The results of the interpolation of groundwater quality factors showed that there is approximately good adaption among groundwater factors and geomorphology and topology of the region. Because of inappropriate irrigation system, the highest concentration is in the northwest and western parts of the region, where there is the minimum height and maximum agricultural land. Growth of arable land and agricultural activities has caused increasing concentrations of studied elements, especially EC.