سید زین العابدین حسینی

Soil erosion and sedimentation are among the major problems and environmental challenges in watersheds. The sediment load in rivers causes numerous issues, such as sedimentation in dam reservoirs, changes in river courses due to sedimentation in their beds, reduced water carrying capacity in waterways and water transfer facilities, and changes in water quality for drinking and agriculture. These problems are of great concern to researchers and water resource managers as they can investigate sedimentation, erosion, and potential effects on biological processes. Therefore, it is essential to investigate and evaluate suspended sediment concentrations to determine water quality and hydrological functions. In this regard, the use of accurate, extensive, and cost-effective techniques, such as remote sensing, is invaluable for improving sedimentation estimation and, consequently, water quality assessment. Understanding the spatial relationships between upstream vegetation and sedimentation is crucial for the effective control and optimal management of water resources and soil. The present study aimed to determine the relationship between vegetation cover and suspended sediment concentrations in the Doab Mereg and Gamasiab watersheds.

In this research, the Sentinel-2 satellite data were investigated in the first step. If there were cloudy conditions, dust particles, or other radiometric problems, they were removed from the calculations. Then, factors such as band type (visible and infrared bands), river width (higher than the image pixel - 40 meters at the Doab station and 80 meters at the Polchehr station), separation power, and sensor location (10 and 20 meters) were considered to select the appropriate image pixel for obtaining the spectral reflectance of water. The pixel corresponding to the hydrometric station and its surroundings was selected to extract the spectral reflectance. Then, the suspended sediment concentration statistics of the Doab Mereg station located in the Qarasu River and the Polchehr station located in the Gamasiab River in the five-year period (2016 to 2020) were used simultaneously to investigate the correlation between the spectral reflectance of the Sentinel-2 image bands and sediment concentration. Next, the Normalized Difference Vegetation Index (NDVI) for the two May and June seasons was extracted using Sentinel-2 images. The relationship between vegetation cover and suspended sediment concentration recorded at the station and extracted from the images was estimated separately.

The results of the correlation analysis of suspended sediment concentration showed that the best result for the Doab and Polchehr stations belonged to band 4 (R2 = 0.86) and band 5 (R2 = 0.83), respectively. The suspended sediment concentrations varied from 0.17 to 76.45 and 0.44 to 118.86 mg/liter in the Doab Mereg and Polchehr stations, respectively. In the Doab station, the depth of the power state had the highest correlation coefficient between the observational data (recorded in the station) and the data extracted from the images. In the Polchehr station, it had a high correlation coefficient in both polynomial and exponential modes. The best values of the coefficient of determination (R2) of the normalized vegetation cover difference index for the Doab and Polchehr stations were 0.98 and 0.64, respectively. This means that the amount of sediment decreases with an increase in vegetation cover. The average values of the vegetation index for the Mereg watershed (0.35) and the Gamasiab watershed (0.28) show the relatively sparse vegetation in the area. The lowest average values of vegetation cover in the studied season (spring) were respectively equal to 0.11 and 0.21 in the Mereg watershed in June and the Gamasiab watershed at the end of May. The results of the regression test showed a strong and significant relationship between the density of vegetation and the amount of suspended sediment concentration recorded in the hydrometric stations of the two basins.

The results showed that six models were extracted for the studied area, which had acceptable and suitable R2 and error values. Among the obtained models, better results were obtained in the single-band model than in the case of using the band ratio. The highest correlations belonged to bands B2, B3, B4, and B5 in the Doab Mereg station, and to B4 and B5 in the Pol Cheher station. The highest R2 values obtained for the two stations were 0.86 and 0.83, respectively, in the exponential model. The results of this study show that Sentinel-2 can be used as a suitable tool to estimate suspended sediment concentrations with acceptable accuracy in small-scale basins and flood conditions, which has been confirmed in a number of similar studies. Sediment rate refers to the positive effect of vegetation on soil protection and the reduction of sediment production and transport within watersheds. In general, the results demonstrate that vegetation has been effective in the quantity and quality of the spatial changes in the sedimentation rate of the basins. In fact, the NDVI vegetation index, as a representative of the vegetation, can be successfully used to create a statistical model of the changes in the sedimentation rate. The revitalization of vegetation should be included in development plans.

The amount of sediment and suspended materials, along with flowing water, is one of the important concerns in the design of hydraulic structures, such as channels, valves, and turbines of dams. This issue is very important from other aspects, such as maintaining the quality of soil in agricultural lands, addressing environmental issues, and managing water resources for drinking and industry. Satellite images, are used to estimate and monitor the water quality of rivers (especially the concentration of suspended load), the sources of pollution, and their movement. They cover a large area of the study area simultaneously, and they also record the spectral reflection of terrestrial phenomena. They have high efficiency. In general, research conducted in the field of the relationship between the spectral reflectance of water (recorded in satellite images) and the concentration of suspended load shows that there is a correlation between the red and infrared wavelengths with the concentration of suspended load. This correlation can be used as an indicator in the evaluation of these bands and to estimate the amount of suspended load concentration. The proper method to find the local model of suspended sediment concentration is to use field data collected during satellite imaging. In this article, the estimation of suspended sediment using Sentinel-2 satellite images in a narrow river has been discussed.

In this research, the estimation of suspended sediment concentration using Sentinel-2 satellite images in low latitude rivers has been investigated. In order to investigate the correlation between the spectral reflectance of the Sentinel-2 image bands and the concentration of suspended sediment, the statistics of the concentration of suspended sediments at the Polchehr station, located in the Gamasiab River of Kermanshah province, in a five-year period (1394 to 1398) were used simultaneously with them. For this purpose, a range of different amounts of sediment has been used, from a concentration of 0.44 mg/liter to 118.86 mg/liter. Out of the total of 24 images suitable for the days of measurement of suspended sediment concentration, four images were removed due to cloudiness, and two images with abnormal reflection higher than the others. Finally, 18 satellite images related to floods were used, of which 12 images (70% of the data) were used in the calibration stage, and 6 images (30%) were used in the validation stage. In this study, the pixel values of the images corresponding to the hydrometry data of Polchehr were extracted in two modes: single band and band ratio. Suitable regression models (linear, exponential, and polynomial) were fitted, and the accuracy of these models has been checked. Finally, the type of algorithm governing the concentration of suspended sediment in Gamasiab River was determined.

In this research, 8 bands of the Sentinel-2 satellite were used as single bands and band ratios. The results showed that the concentration of suspended sediment in the Polchehr station varied from 0.44 mg/liter to 118.86 mg/liter. Based on the results, it was found that dates with higher reflectance values had higher measured suspended sediment concentrations. The highest amount of reflection from the water surface was observed in band five (703 nm) and B8A. Also, from the obtained models, it was found that in the case of a single band, better results were obtained than when the band ratio was used. The exponential model related to band 5, which had a higher correlation with all sediment values, and the coefficient of determination was obtained as 0.83. To evaluate the results of the current research, the root mean square error of the evaluation index was used, and its value was 33.95 for the 5-fold band. It was found that the modeling of the suspended sediment parameter was done with proper accuracy. The results of the present study showed that satellite images can be useful for evaluating water quality monitoring. In addition, this study showed that Sentinel-2 can be used as a suitable tool for estimating suspended sediment concentration with acceptable accuracy in small-scale watersheds and flood conditions.

The results showed that the Sentinel-2 satellite images and the equations obtained in the present research are suitable for calculating the suspended sediment concentration in the Gamasiab watershed of Kermanshah province. Based on the results, it was found that nine models for the studied area had acceptable and suitable coefficients of determination and error values. Among the obtained models, it was found that better results were obtained in the single-band mode than in the mode where the band ratio was used. Also, the results showed that the exponential model related to Band 5, which had a higher correlation with all the sediment values, can be used to estimate the suspended sediment concentration from Sentinel-2 satellite images in the Gamasiab watershed of Kermanshah province when it is possible to collect no field data. The present study will be useful as a reference for future research in investigating and estimating suspended sediments using satellite data. In addition, considering the importance of suspended sediment in water quality and its effects on the environment and economy of the region, the use of suspended sediment estimation methods using satellite data can be used as a fast and efficient way to monitor water quality in narrow rivers.

Subsidence is an environmental phenomenon caused by the gradual subsidence or sudden subsidence of the earthchr('39')s surface. The phenomenon of subsidence in residential, industrial and agricultural areas can cause catastrophic damage. In most parts of Iran, there is a high correlation between land subsidence and the decrease of groundwater level and consequently the density of soil layers. In this study, using two time series of radar images with artificial apertures from Sentinel sensors belonging to 2014 and 2019, the amount of subsidence in Damaneh plain (Frieden city) was calculated. Wells were studied in the period 2014 to 2019, the results of the study of the correlation between land subsidence with changes in groundwater level at the level of 95% was significant. In the continuation of the research, using the logistic regression model, the subsidence trend in the study area was predicted and a subsidence probability map was prepared and created as a dependent variable for the logistic regression model. The independent variables used included altitude, slope, slope direction, geology, distance from the road, distance from the river, land use, distance from the village, groundwater level, piezometric wells. The output of the model is subsidence risk zoning map which was created in five classes. The accuracy and validation of the logistic regression model was evaluated using the system performance characteristic curve and the accuracy (0.89) was obtained. The good accuracy of the logistic regression model in producing the probability map Subsidence is in the study area. In the output of the model, it was found that the area of ​​1980 hectares, equivalent to 7.9%, has a very severe subsidence that has put the situation in a dangerous situation and the need for control and management to reduce this destructive effect.

One of the most important security challenges in e-banking security centers is the inability of the internet to deal with attacks. These attacks are easily implemented and can be controlled locally or remotely. Most of these attacks are successful in reaching the main targets of the attack and bring the attacker to their desires. The reason for this is that there are many mechanisms for launching attacks based on the characteristics of the victim's server, which makes it impossible to provide a comprehensive defense solution against the attacks. Several strategies have been proposed to identify and deal with these attacks. In this paper, a combination of algorithm for selecting genetic features and machine learning methods, including decision tree algorithm, deep neural network and KNN, are presented. Provide guidelines for validation, the results obtained with other techniques such as machine learning techniques and combined with other optimization methods are compared and evaluated. In this research, 10% of KDD Cup 99 dataset for simulation has been used. First, in the preprocessing of data, the values of all attributes are converted to numbers, and the output characteristic values are changed to two values of zero and one. The results of the research indicate that the accuracy of the proposed strategy for detecting intruders compared to other recent methods is about 5%.

Providing good quality drinking water is one of the most important concerns of today's societies. Using a proper system for the fair distribution of potable water is very necessary and evidently the type of the system will lead to different amounts of water use per capita. Today, the dispute over good quality water resources in arid regions has escalated, Governments are forced to use separate drinking and sanitation water systems. Understanding the consumption of people in the form of per capita is a prerequisite for the proper design of drinking water distribution networks, the data of which are collected and analyzed in different ways. Quality of groundwater resources in Bajestan region, has led to the plan of separate drinking and sanitation water, with the establishment of government water collection stations since 2014. The purpose of this article is to estimate the per capita drinking consumption by query method by considering 378 samples and random sampling at certain distances from each station. The amount of per capita obtained is estimated at about 3 liters, but its amount has a different distribution in different city districts ranging from 2.5 to 4.5 liters. The highest amount is obtained for the new districts with villa texture and the lowest for the zones with more apartments. The results of the survey of the plan and the problems and consequences of its implementation showed that about 69.03% of people are using the water of these stations for drinking and tea, which is the criterion for determining per capita; The biggest problems of withdrawal stations are the numerous breakdowns of the stations and difficulty harvesting them, which requires the revision of some network operations.

In order to supply the drinking water for inhabitants of arid areas always have several challenges. The main source of fresh water supply in these areas is groundwater, but in recent years, increasing harvests and declining aquifers have increased salinity. Bajestan watershed is no exception of this issue and the main source of drinking water and sanitation is groundwater sources from the Playa, which is of very low-quality water. By decreasing the quality of groundwater resources has created the project to separate drinking water and sanitation by creating “The Government Drinking Water Stations”, since 2014. The purpose of this study is to investigate the rate of realization of this project implementation in order to quality drinking water supply. For this purpose, some of water samples was taken from the network and drinking wells, then the samples were compared with National and International standards and prepared the groundwater resources quality map.

In this study, at the first stage, the water samples taken from drinking wells and distribution network in the same period (2014-2019) were collected and compared with National and International standards. These standards included the standard of the Industrial Research Organization of Iran (1053 Report), WHO, the United States Environmental Protection Agency (EPA), the European Union (EU) and Schuler diagram. Then, Prepared the maps based on 1053 and Schuler diagram (The most common drinking water quality standards in Iran) which were selected by choosing the best interpolation method in the field of Geostatistical by choosing the lowest value of RMSE.

The results of this research showed that all of the quality parameters of distribution network’s water samples were within the standard condition, the values ​​of all the quality parameters were equal or even lower than the standard value of the indicators, So the conditions are optimal. While the water quality parameters in drinking water supply wells were of unfavorable quality according to the values ​​of the standards used in the research; These are EC, TH, TDS, Na, CL ​​in the water samples obtained from the wells on the Playa were 4 to 6 times and in other wells on the plain were 1.5 to 2 times the values ​​found in the standard indices. The results of the interpolation of the quality parameters of the plain's groundwater showed that the Co-Kriging method has the lowest Error in the main parameters of water quality determination, including EC, TDS and TH, which shows the high correlation of the parameters, there was a high correlation of groundwater in the plain with each other.

Comparison of the samples in the two parts of the wells and the drinking water distribution network showed that the current plan has sufficient usefulness to providing the quality the drinking water. Also, based on the map of the quality of the groundwater resources of the plain, the playa has the lowest quality of water resources and the wells located in the plain area have better quality.

One of the major challenges in arid regions such as Iran is the supply of water with appropriate quantity and quality. Drought, disputes over water resources, and providing good quality and quantity water for drinking, agriculture, and industrial sector, have forced governments to use desalination technology or transfer water among watersheds, Water desalination is one of the solutions to providing drinking water in Central Iran and coastal areas. Bajestan plain is no exception and has been using this method for about 16 years to provide drinking water and health for residents. Investors have recently been encouraged to build mineral water plants in arid areas; While the socio-economic and its environmental consequences are not yet clear. The results of this study showed that to supply fresh water from desert saline water with EC about 7500 (µs/cm) and reverse osmosis method with a production volume of 1000 (m3/yr), the price per liter of water is equivalent to 45.067 IRR. In this process, around 500 m³ of saline water and more than 6 tons of salt will be produced, too. This amount of salt will increase the salinity of the lands around the pistachio fields and orchards by 2 to 3 times and decrease the yields by more than 60%. Results showed if the bottles are not recovered, more than 18 tons of polyethylene will be produced. The economic evaluation shows that the value of the Net Present Value Index is negative and Internal Rate of Return is not acceptable, and the B/C is 0.46, which indicates that it is not economical to implement. Implementation of this plan in other arid regions with these conditions will have similar results.

The present study was conducted with the aim of analytical evaluation of green urban development trends in District 22 of Tehran during a five-year period from 2011-2016.              The research method was descriptive and analytical. Research data were collected in two time periods (2011 &2016)        from official documents and databases of governmental and non-governmental organizations, especially environmental deputies and Tehran Municipality. In order to determine the extent of the effect of each of the criteria for evaluating the green city and scoring their performance in this 5-year period, experts used two separate questionnaires. Data analysis was performed using Expert Choice software and performance evaluation matrix and Excel spreadsheet. The innovation of the research is the use of various and valid criteria in relation to the green city in order to "evaluate" the performance of green urban development during a five-year period in the 22nd district of Tehran. The results of the study showed that in the study period, out of 39 criteria, 18 criteria had a good performance during this period, including: water sustainability policy, daily average SO2 and per capita green space, and 21 other criteria had ineffective or undesirable performance. The final result of the evaluation of the performance of the green city showed that the development of the green city in this region is in a moderate position due to its significant environmental potentials and is relatively far from the ideal point.

The purpose of current study was to study the physiological and phonological traits of Salivia eremophila Boiss. As a native and medicinal species in three rangeland sites in Yazd province (Iran). For this perpose three ares (Damaghan, Tange-Chenar and Ghavam Abad) and three sites in each area, were investigated in terms of Soulobe carbohydrates, Proline, Chlorophyll and Carotenoids in aerial parts of Salivia eremophila in two phonological stages: Flowering and seeding. Plant sampling was done based on randomized-systematic method in 1M2 plots, along with 50 m2 transects. Also, phenolocical diagram of Salivia eremophila was figured based on consecutive field investigations. Data were analyzed at level of 5%. The results showed that there are significant differences in interaction effects among phonological stage, site and area. site No.1 of Tange-Chenar had significant difference in Chlorophyll (a & b) with the other sites (p<0.05). As for Carotenoids, There were significant difference between sites and areas, in which site No.3 of Damgahan in seeding stage, and site No.1 of Tange-Chenar had the higher rates. Also, the rate of Proline in site No.1 of Damgahan (in flowering stage) was higher than the other sites and areas and it showed significant difference. The amount of Soulobe carbohydrates had significant difference in sites and phonological stages in general (except flowering stage). In overall, the climatic conditions of the sites of studied areas are almost similar in terms of annual rainfall, as well as rangelans type and altitude, and this can affect the occurrence of low changes in plant nutrients

Due to the low annual precipitation rate and, therefore, the existence of a weak and fragile ecosystem, arid regions are more subject to drought. Moreover, significant fluctuations in the temporal and spatial distribution of precipitation make drought forecasting in these areas a complicated task. Having a dry and fragile climate, Yazd Province has experienced numerous droughts within the past few decades. Therefore, it is highly important to monitor and forecast drought in this region. Population growth has increased water demand. Moreover, the increase in the concentration of greenhouse gases due to rising fossil fuels consumption has caused global warming and climate change, changing the hydrological cycle components including precipitation patterns (snow and rain). Therefore, climate change has changed the frequency, severity, and duration of droughts in many areas, especially in arid and semi-arid regions. So far, several indices have been developed to assess drought. This study used the RDI, which is based on precipitation (as system input) and potential evapotranspiration (as output), to estimate the drought. Furthermore, there are several methods for forecasting drought, among which projections of global climate models derived from greenhouse gas emission scenarios are quite common.

This study sought to analyze the efficiency of global climate models in predicting drought in arid regions (Yazd Synoptic Station, Yazd, Iran). To this end, 1961 to 2005 was selected as the base period, RDI values of which were imported to downscale the model (SDSM). Moreover, 2006 to 2018 was selected as the forecast period whose data were not imported to the model. Finally, the predictions of the model for the period 2006 to 2018 were compared with the observed RDI values of the same period for time scales of one, three, and six months. Accordingly, first, the climatic data collected from Yazd Synoptic Station (minimum and maximum temperature, relative humidity, sunshine hours, and wind speed) were prepared, and then the potential evapotranspiration (PET) was calculated for the period 1961 to 2018 via FAO-Penman-Monteith method. RDI value for the period 1961 to 2018 was then estimated on a monthly basis.Moreover, to predict drought through global climate models, CanESM2 global model forecasts were obtained based on the RCP8.5 greenhouse emission scenario from 2006 to 2018 for monthly precipitation, minimum temperature, maximum temperature, average temperature, sunshine hours, wind speed, and relative humidity. Using SDSM statistical downscaling model, the observed data for the period 1961 to 2005 and the projections of the CanESM2 model for the period 2006 to 2018 were downscaled. On the other hand, the mean surface temperature predictor was used to a downscale minimum and maximum temperatures and sunshine hours. Wind speed and surface-specific humidity predictors were also used to downscale wind speed and relative humidity outputs, respectively. Furthermore, to increase the accuracy, three predictors of precipitation, surface specific humidity, and mean surface temperature were used to downscale precipitation outputs. Finally, as for the high spatial and temporal variability of precipitation in arid regions, possible biases in precipitation data were corrected using the Linear Scaling bias correction method, which is based on the average difference between monthly observed time series and GCM historical simulations time series over the same period of the observed series. These differences were then applied to the future GCM simulated climate data to get bias-corrected climate variables.

The results obtained from the application of the FAO-Penman-Monteith method indicated that the variable trend presented by PET values during the study period was mostly induced by changes in wind speed fluctuations. Moreover, downscaled precipitation values showed a more significant error rate than those of the downscaled temperature outputs, probably due to the fact that precipitation values had more variability than the temperature ones, especially in arid climates. On the other hand, the application of the Linear scanning bias correction model showed that the precipitation values downscaled by SDSM for the base period (1961-2005) were overestimated compared to the real precipitation data over the same period. Therefore, the overestimation was corrected using the Linear scanning bias correction method. After correcting the probable precipitation biases and calculating the RDI index, the results suggested that the use of the Linear scanning bias correction model remarkably increased the accuracy of CanESM2 precipitation outputs.Then, the RDI was calculated by replacing the predicted precipitation and potential evapotranspiration values with the real data in the period 2006 to 2018 by measuring the potential evapotranspiration based on the data mentioned. Accordingly, R2 between real RDI values and the CanESM2-extracted forecasted RDI values for the 2006-2018 period was 0.472 for the 1-month time scale, while R2 was 0.738 and 0.762for for 3 and 6-month time scales, respectively.

The results indicated that the model presented a good performance at 3 and 6-month timescales. Moreover, considerable fluctuations in one-month precipitation values resulted in high variability of the one-month RDI time series, decreasing the model's performance at this timescale. Therefore, for projecting precipitation in arid and hyper-arid zones, a bias correction method should be applied to minimize probable biases. Furthermore, the comparison of actual droughts that occurred from 2006 to 2018 with the values ​​predicted by the model at 1, 3, and 6-month time scales showed that the CanESM2 model predicted the drought patterns with relatively good accuracy at 3 and 6-month timescales. However, as for the one-month timescale, the model presented lower efficiency than the other two time scales due to more fluctuations. Therefore, it can be concluded that GCM forecasts have a relatively acceptable efficiency for long-term drought prediction in arid climates.

Digital elevation models and its derivatives are important factors for watershed modeling. It is obvious that DEM errors adversely affect the accuracy and thereby modeling of natural processes. This problem along with the impossibility of measuring all elements of nature, has led to a major evolution in the way of understanding and explaining phenomena. In this way, we can use the fractal geometry as a quantitative tool for modeling many complex natural phenomena. In fact, geophysical phenomena such as drainage networks are fractal phenomena with fractal behavior. The purpose of this paper is to evaluate sensitivity of the drainage networks based on DEMs (ASTER & SRTM), flow direction algorithms (Single Flow Direction (D8) and Multiple Flow Direction (MD8)) and topographic maps of 1:25000 in order to study the fractal dimension of drainage network on geological formations of Yazd-Ardakan basin. The results showed that the least difference in the length and the rank of the stream belonged to the drainage network obtained from the topographic maps of 1:25000. After the topographic maps, ASTER and the multi-flow direction algorithm are close to real ground map. Even though the multi-flow direction algorithm shows more detail on the drainage network. But it is not close to real ground map. The difference is particularly noticeable in the first rank of streams. Due to the very high sensitivity of the fractal dimension to the smallest change in drainage network conditions, the drainage network obtained from topographic maps were used to calculate the fractal dimension. The mean fractal dimension of 1.149, 1.16 and 1.207, respectively, represents Taft, Granite and Kahar formations. There is a significant correlation between fractal dimension and sensitivity to erosion of geological formations (level 0.99). In fact, the fractal dimension increases with increasing the sensitivity to erosion along with the drainage density in geological formations. The results showed that fractal dimension allows for a quick and accurate analysis of sensitivity to erosion of the formations of this area.

This study was conducted to assess the selected indicators in the process of green urban development in District 22 of Tehran during a five-year period from 2011 to 2016(A study that has not been conducted for a period of time from this emerging and developing area of Tehran). For this purpose, In addition to the air quality criterion as the preferred criterion, other effective criteria for measuring urban development were identified and clarified based on theories, views and case studies in the context of the above objectives. Data analysis was performed with Expert Choice software and performance evaluation matrix and Excel spreadsheet. The results of this study indicate that the performance of clean air policy as a selected criterion during the period under review, optimal performance, particulate matter smaller than 10 microns (PM10) and sulfur dioxide (SO2), moderate performance and nitrogen dioxide pollutant (NO2) also had poor performance. The functional performance score of the green city in the study area during the five-year period was 0.545, i.e., 54.5% of the changes in urban development in this area in this period has been achieved based on the criteria of the green city and this indicates that green urban development Its significant environmental features are in the middle position and it is relatively far from the ideal point.At the end of the study, after identifying the functional weaknesses, some strategies for optimal and more efficient planning are presented.

Soil salinization is one of the dominant processes of land degradation in arid and semi-arid regions.  Soil salinity is one of the most important problems affecting many parts of the world. Salty soils in agricultural areas reduce the annual crop yield of most crops. As a first step, soil sampling and Landsat images are pre-processed. Different salinity indices such as NDSI (normalized salinity index), BI (brightness index) and SI (salinity index) were used to map the salinity of the study area. As well as Laboratory measurements of electrical conductivity (EC) and soil acidity (pH) have also been performed. In this regard, the values of three salinity indices NDSI, BI, SI for 2017, 2015, 2010, 2005, and 2000 were calculated in ENVI and GIS software. Based on the results of satellite imagery analysis, saline soils in the west and southwest of Ilam province (sub-basins of Mehran, Musian-Abdanan, Abbas-west-east and Molab basins) are located. According to field surveys and soil sampling for different areas of Ilam province, it was found that pH values below Mehran basin, south Dehloran and downstream of Simareh Dam are above 8.5 and indicate alkaline and sodium soils. And other examples show unusual, up to slightly salted soil. This means that the results of the remote sensing analyzs partially confirm the data obtained from estimating soil EC and pH values in the study area.

Drought is a natural hazardous phenomenon occurring in all climate types. However, it affects arid and semiarid regions more intensely than other areas. It also severely affects both the quantity and quality of water resources in arid zones. Moreover, land-use changes and urban and agricultural development also adversely influence water resources in these regions, especially groundwater resources.The extraction of a significant portion of drinking and agricultural water from groundwater resources has led to a sharp decline in groundwater storage in Iranchr('39')s arid and semiarid regions. Furthermore, as mentioned before, frequent droughts and land-use changes have affected these resources. This study, therefore, sought to investigate the effects of meteorological drought and land-use changes on groundwater quantity and quality in Darab plain, Fars Province, Iran.

Darab Plain is located in the south of Iran. The water supply in this plain is highly dependent on groundwater. The mean annual rainfall is 275 mm, and the mean annual temperature is 22 0C. In this study, data regarding precipitation, groundwater level, and salinity were used to estimate SPI (Standardize Precipitation Index), GRI (Groundwater Resources Index), and SECI (Standardized Electrical Conductivity Index). SPI is considered as the indicator of meteorological droughts. GRI quantifies changes in groundwater levels as a standardized index. SECI is applied to estimate any potential shifts in groundwater quality. Land-use maps of the basin for 2001, 2009, and 2017 were prepared using satellite imagery. Moreover, Landsat TM, ETM+, and OLI sensors were used. It should also be noted that land-use maps were created using the Supervised Classification method (Maximum likelihood algorithm). The produced maps included five classes: urban area, farmlands, gardens, rangelands, and bare lands.

SPI results showed normal classes for most of the years throughout the study period (-0/99 to +0/99). However, the trend line indicated an apparent decreasing trend for SPI during the period. Therefore, it could be concluded that the region is experiencing more droughts. A study of groundwater level changes suggested a continuous reduction of 36 m for the entire study period. While the comparison of SPI and GRI showed a general decreasing trend for GRI, it could be seen clearly that SPI changes caused GRI shifts. Moreover, droughts accelerate GRI reduction, and SPI growth either reduces GRI decreases or increases it slightly.On the other hand, SECI results indicated the salinity growth and quality reduction in the region. During the study period, the plain experienced a 293.6 µmho/cm increase in salinity. Furthermore, the comparison of GRI and SECI showed that any reduction in groundwater level would result in more saline. The comparison of land-use maps during the three years (2001, 2009, and 2017) also proved that agricultural uses increased by only 0.26% in 2009 compared with 2001. However, in 2017 compared with 2009, such uses decreased by 1.62%.The relationships between SPI and land-use changes with GRI and SECI were also investigated, indicating that droughts and land-use changes directly affect the quantity and quality of groundwater in Darab Plain.

Climate change has affected many parts of the world, changing drought characteristics in many regions. Therefore, the subsequent changes in water resources could be considerable. Furthermore, water resources are under pressure for population growth and land-use change. In this study, the collected data was divided into three 8-years periods (1993-2001, 2002-2009, 2010-2017), and the averages of SPI, GRI, SECI, and land-use were calculated for the three periods. The results showed that the increase in the severity of drought and the rise of the agricultural lands in the second period compared to the first one caused a decrease in water quantity (GRI decrease) and quality (SECI increase). However, a decrease in the severity of drought and the fall of the agricultural land-use in the third period compared to the second one lowered the rate of groundwater level decline (compared to the rate of GRI decreasing in the second period). In the third period, SECI increased (less quality) in response to the GRI decrease. The results showed that groundwater resources in Darab Plain were strongly dependent on both drought and land-use changes. The groundwater quality in the region was also directly affected by changes in groundwater level.

Understanding the status of discharge and sediment of watersheds area provides an understanding of the hydrological processes. Uniform assuming of discharge and sediment in a watershed leads to the application of unit planning and management for the entire watershed and leads to a failure to achieve the goals. The present study was conducted with the aim of studying spatial variations and zoning of discharge and sediment values in Ardabil province during 10 years (2005-2014) at 37 stations with hydrometry in Ardabil province. IDW interpolation methods, simple kriging, ordinary kriging and cokrigring were investigated to determine the best method for studying spatial variaions, discharge and sediment variables. Based on the results of the evaluation indices of IDW (RMSE=1.172, MAE=0.644, MBE=-0.2, MSE=1.373) and cokriging (RMSE=0.107, MAE=0.08, MBE=-0.001, MSE=0.011) and the correlation coefficient between measured and estimated values by IDW (r=0.429) and cokriging (r=0.554) respectively, as the best method for evaluating the discharge and sediment variables were chosen. Based on the results of the IDW method, the amount of digestion in the Western parts of Ardabil province is greater (4.84-5.8 m3/s), and in the central section, this amount is the lowest (0.04-1 m3/s). According to the results of the interpolation of the sediment variable with the cokrigring method in the Western and Southern parts of Ardabil province with a higher amount of sediment (0.16-0.19 ton/ha/year) and in the central parts of the sediment deposition (0.01-0.04 ton/ha/year).

Land degradation is a global challenge that results in reduced soil fertility and eventually becomes one of the major environmental issues worldwide. The issue of land use and land cover changes by mankind is one of the most important factors of environmental change at the local and global scale which has significant implications for ecosystem health, water quality and sustainable land management (Foley et al., 2005; Lubchenco, 1998). The problem of land degradation in the Ilam province is affected by a combination of natural and anthropogenic factors, including deforestation, drought, overgrazing, intensive agriculture, increased sediment performance due to soil erosion, evaporation, dam construction and drought. These environmental problems are ultimately linked to changes in land cover and land use. Therefore, it is important to consider land cover and land-use changes to monitor environmental changes and sustainable resource management plans for fragile ecosystems such as Ilam province and provide results to area managers and planners for restoration and prevention.

In this study, we used MODIS Terra Satellite Land Cover Products (MCD12Q1) to study the monitoring of land cover changes in the Ilam province for the period of 2001 to 2013. All data for the study area were mosaicked and sampled with the UTM Global Coordinate System, using the nearest neighbor sampling method. Then they were Geo-referenced and finally, on Gis-Envi software correction operations (geometric, radiometric and atmospheric) were run and then the study area was clipped. The method initially classified the images into 17 classes and then calculated the number of pixels (zeros up to 255) of each class for the duration of 13 years and mapped the trends and percentages of changes occurring to each class.

Shrub forests have begun to grow in size since 2009 and their numbers appear to have increased in the coming years. Conversely, forest-savannahs and savannas in 2001-2007 had a small area (34 pixels in total) of their own, and since 2007 species of this type have become extinct and are not observed at all, in the studied level. The water levels (code zero) in the study area underwent very little change from 2001 to 2013, and only from 2004 to 2008 did the extent of the water levels show greater values than other years. The maximum amount of water in 2005 was 29 pixels (that means, 7250000 m = 500*500*29), which is mostly related to the Karkheh and several pixels of the Simare River in the south and east of the border. But water levels appear to have increased since 2013 due to the construction of several dams in the study area. Also, the levels for urban and residential areas (Code 13) from 2001 to 2013 are consistently 159 pixels per year across the study area, and we don't see any increase or decrease in it. Finally (code 7, 10, 12 and 15), respectively, each are 564.424 and 8.953 and 47.030 and 443.520 pixels for 13 years. That is %99.78 of the area covered. Among these areas, open forest shrubs with 564,424 pixels and no vegetation areas with 443,520 pixels had the highest amount of land cover (%94.5) in the area.

According to the extracted map (Map No. 2) the story lacking vegetation named Code 15 which is marked yellow in the map, is mostly located in the west and southwest of the study area, including the lowland basins, namely Western Abbas plain, Eastern Abbas plain, Chenane, Abadan, Mehran, Dehloran, Salehabad, and Sumar. In some years, due to the increasing trend of land degradation, it is advancing toward the center and east of the region. Overall, the trend of changes in the amount of no vegetation levels over the past 13 years show an increase, and this can be a concerning issue in terms of land degradation. This should be seriously taken into consideration. As the maps show, there is a decreasing inclination in the trend of open shrub forest zones during the study period as well.

Quantitative description of valley profiles can help us to identify its geomorphologic and dynamic properties and a useful tool for separating the valleys created by various processes. In this study, the Longitudinal and Cross-sections of 15 valleys were investigated in three geological formations of Kahar, Taft and Granite. Fractal properties of valleys along with the mathematical functions and two Vf and Fr indicators were used to study valley morphology. The average of Vf index was calculated in Kahar, Taft and Granit formations 5.56, 3.52 and 1.38, respectively. Also, the average of Fr index in three formations was calculated 0.07, 0.20, and 0.17, respectively. The results indicated heterogeneity in the lithology and structural status of valleys. According to the results, the shape of the valley, from Kahar to Taft formation, is U profile to V-shaped profile. The results showed that less curvature profiles are fitted with linear functions and profiles with more curvature fitted with polynomial functions. In fact, the polynomial functions, especially the fourth order, have high ability in modeling the Longitudinal and Cross-sections of the valleys. Subsequently, multifractal analysis of cross-sectional valley, Using the general multifractal dimensions (Dq) and the technical spectrum f(αq), showed that these sections are transmitted from mono-fractal to multifractal. None of the valley sections in Taft formation has multifractal properties. In a number of Cross-section valleys of Granite and Kahar formations, the multifractal approach seems to be more appropriate. Because of the fractal parameters may vary depending on the locations.

The estimation of water demand is one of the most important factors in managing water resources and the necessities of any irrigation and drainage plan. Estimation of the potential of the reference plant (ET) should be estimated to meet the water requirement. The level of utilization of surface water and underground resources in each region is directly related to the water needed to irrigate agricultural products in that area. In this study, which was conducted in the watershed of Yazd-Ardakan plain, OPTIWAT software was used to calculate the need for water. Irrigation and horticultural products of Yazd-Ardakan plain are about 54,000 ha. The water required for irrigation of these three products is 917.6 × 106 m3, which accounts for approximately 70 % of the water needed for irrigation of the total crops in the study area. The amount of water need for irrigation of crops and orchards of Yazd-Ardakan plain was achieved with current crop and current yield (45%) equal to 831.7 × 106 m3. The amount of water required for these products for drip irrigation and efficiency of 60, 75 and 90 percent were calculated 594 × 106 m3, 464.7 × 106 m3, and 382 × 106 m3, respectively. Therefore, it can be concluded that by changing the pattern of cultivation and increasing the irrigation rate, the use of the aquifer in the plain can be reduced and added to the amount of underground storage.

Drought assessment and monitoring using traditional methods rely on rainfall data, which are limited in arid lands and often is very difficult to obtain near real time and costly. In contrast, remote sensing technology is a method for monitoring of large-scale drought.In this research, drought condition was analyzed using drought indices such as TVDI and NDVI from MODIS sensor data for the Yazd-Ardakan plain, Iran. First, relationship between the drought indices with climatic elements were detected. Coefficient of correlation between TVDI and SPI_6 and SPI_12 were 0.68 and 0.71, respectively. Correlation between NDVI and SPI_6 and SPI_12 were 0.49 and 0.51, respectively. Point correlation between TVDI and SPI_6 in 2004 (as a normal year), 2007 (dry) and 2012 (wet year), were 0.64, 0.78 and 0.67 and for the SPI_12 in the above-mentioned years were 0.65, 0.79 and 0.69, respectively. In other word, efficiency of the TVDI in 2007 is better than the other two years. Correlation of NDVI and SPI_6 in 2004, 2007 and 2012, were 0.41, 0.50 and 0.56, respectively. The correlation between NDVI and SPI_12 in 2004, 2007 and 2012, were 0.52, 0.57 and 0.59, respectively. TVDI which takes into account thermal and reflective bands, and soil moisture, is more accurate than the NDVI, which considers only amount of vegetation of the study area. Results showed that the relationship between vegetation and temperature is negative, while, the relationship between vegetation and precipitation is positive. Using of TDVI can compensate defects of the NDVI and used for identifying and monitoring drought.

Landslides are classified as natural disasters that pose financial losses and deaths in the country annually. Besides, identification of high risk areas can be effective in reducing the damage and improving decisions on land-development policies. Preparation of landslide zoning map makes it possible to identify the vulnerable areas and use them in various environmental programs. In this study, the multi-criteria methods were presented to create the landslide capability map using geographical information system and decision rules. The aim of producing landslide capability map is to reduce the risks of landslides and support land development policies in the watershed scale. In this regards, different factors such as geology, slope, aspect, landuse, distance to road, rivers and fault maps were employed. Additionally, slope and river maps were expressed as restrictions. After weighing the factors and sub-factors, the landslide sensitivity maps were converted to the values ranged as 0-1. Afterward, in terms of sensitivity the final map was classified to three classes of low risk, moderate risk and high risk. The results showed that some factors such as precipitation, geology and slope have the highest impact on landslide occurrence and should be considered with more emphasis in order to be used for planning and policy making in the study area. According to the results, the first group factors including geology, landuse, slope and aspect and the second group factors including land distance from fault, river, road and rainfall are weighed as 0.6 and 0.4, respectively.

Introduction Water is a limited natural resource but essential for human survival. Among the water resources, groundwater is considered valuable for a variety of human activities. In the watershed Bajestan plain, the exploitation of drinking water is mostly done by wells especially due to the depth of water level. The purpose of this study is to unfold the qualitative parameter of ground drinking water in the Bajestan Plain based on Standard Classifications by Schoeller and prepare drinking water quality maps and then adjust the groundwater quality in terms of parameters affecting the quality of drinking water. Also determining the most appropriate points based on locally available information is another attempt of the study.   Methodology In the present study, the measured parameters related to the Bajestan plain were obtained from the regional water company of Khorasan Razavi and the initial classification was carried out on them. Accordingly, 76 wells and the groundwater quality data were selected with a relatively complete statistic during the 2004-2011 periods. In order to evaluate the quality of drinking water, the parameters of sulfate, sodium, chloride, TDS and TH were extracted from the wells. Finally, qualitative changes to groundwater were investigated based on a 4-year period and appropriate points were noted down. In the next stage, the quality changes to drinking water were investigated in two 4-year periods and finally suitable drinking water areas were determined based on the passive defense technique and TDS.   Results and Discussion The results showed that the best interpolation method for water quality parameters was the Statistical Estimator (IDW). In the Bajestan plain, 26.5% of the region was in inappropriate class, 66% had an unpleasant quality and only 7% of the region had a moderate drinking quality located in the mountain range of the study area. At the end, suitable places for drinking were determined. In other words, these are water harvesting sites for agriculture but suggested that those wells be sealed and be used in case of drinking water emergencies.   Conclusion The extent of these classes indicates the low water quality in the region. As geological maps indicate, some places adjacent to the Cretaceous limestone, have moderate water quality while the plain area has inadequate quality water. Further, in the area adjacent to Playa, there is completely unpleasant quality of drinking water. According to reports from the Water Authority, drinking water provided to the region is mountainous and medium in quality. Also, the results of the qualitative timeliness of these resources indicate that the quality of groundwater resources is increasing with parameters reduction and hence; based on the amount of TDS allowed for drinking water, agricultural wells should be sealed and protected in some areas in order to be used in emergency.

Deforestation or vegetation degradation is one of the main drivers of global earth changes, which has significant consequences in terms of ecosystem performance and biodiversity conservation. One of the ways for studying vegetation changes as the most important indicator of land degradation is remote sensing. In this study, in order to monitor the vegetation degradation trend in Ilam Province.After obtaining and preparing the required data (410 downloaded images) in the ArcGIS and Surfer software, the multiplication, mosaic and georeferencing operations are made. Converting format of images into ASCII is the next stage of the study. By converting this format, the total number of 953552 pixels is studied within the range; after removing the lost and negative values, 328042 pixels are analyzed. Besides, using parametric statistical method of the classical linear regression and programming in R software, the trend of slope variations and significance of slope variations of vegetations are obtained for the 17-year period (2000-2016). Results of this study show that the focus of the highest trend of declining slope variations (trend of negative slop variations) is in the NDVI index across the western half of the studied area and the focus of the highest trend of increasing slope variations (trend of positive slop variations) is in the NDVI index in the center and east. Significance of the trend of slope variations also approves this claim. Thus, the focus of the highest trend of slope variations (negative) in the west and southwest of the studied area along with the highest trend of slope variations (positive) in the center and east is significant at the probable level of 0.05

In water systems, precipitation is considered as input and evaporation as the output of the system. Water availability can be estemated from the relationship between these two factors. Therefore, evapotranspiration is the most important factor after precipitation in hydrological cycle. Evapotranspiration is influenced by climatic parameters such as temperature, wind, humidity and sunshine hours. In this research, changes in PET and effective climatic parameters, influencing on PET changes including temperature, wind, humidity, and solar radiation were investigated. For this purpose, PET in 14 weather stations of Yazd province were calculated using the FAO-Penman-Monteith method. Due to the lack of sunshine hours data in some stations, regeneration of the incomplete data was done by using regression method. Due to the lack of wind speed data at some stations, their reconstruction by using data from other stations was done by applying three methods of Inverse Distance Weighted, Kriging and Cokriging. After calculating potential evapotranspiration, PET data were zoned and their monthly and annual trends tested by Mann-Kendall test. Despite occurrence of climate change and increasing of temperature in 13 stations out of the 14 stations, it is expected an increase in potential evapotranspiration in past few decades, while, there is a decreasing trend in PET. Investigating on the effective parameters in potential evapotranspiration showed that wind speed has declined in the last few decades, and despite of an increase in temperature, potential evapotranspiration rate reduces in 64.3% of the stations. General trend of evapotranspiration was -0.86 in this period, which indicates a decrease in evapotranspiration in the Yazd province.

Understanding chemical changes in groundwater and their mapping play a substantial role in optimal management of groundwater in an area. There are various methods for investigation and classification of groundwater chemical features, and selection of appropriate method depends on the purpose, conditions of the area and available information. Geostatistical methods and GIS can be useful tools in this regard. The aim of his study is to investigate the spatial variations of groundwater quality and select the best mapping method for the management of groundwater resources in Segsi plain. In this paper, the distribution of quality pollutants pH, TDS, Hco3, EC, Ca, Mg, TH, Na and So4 in groundwater of Segsi plain was investigated using inverse distance and geostatistical methods, distance and bearing functions, local, general and ordinary Kriging estimator software ARCGIS9.3. Accordingly, the sample from 445 groundwater wells, springs and canals were examined. After evaluating variograms and determining the spatiality of the changes in the studied parameters, interpolation of parameters was performed and the best evaluation model with lowest RMSE was selected through mutual evaluation technique and the root-mean-square error. Findings: The results showed that all parameters had the lowest RMSE using the ordinary Kriging method and it was used for mapping the spatial distribution of water quality parameters. Results from mapping indicated that Na, Ca, Mg, So4, Hco3 and pH had no limitation and EC, TH and TDS had limitations in terms of drinkability. According to the results, application of the ordinary Kriging method is recommended for more precision, less calculation and less data demand among various interpolation methods for the groundwater mapping.