جستجوی مقالات مرتبط با کلیدواژه « GIS » در نشریات گروه « آب و خاک »

There are two approaches in dealing with environmental changes. The first approach is based on ignoring these changes and continuing the current situation, which will result in further environmental destruction. The second approach is based on identifying these changes from the past to the present and formulating an environmental management plan to control these changes and plan for improving the environmental situation. Wetlands are one of the most important natural habitats in the world and have many values and benefits, especially in energy circulation in the environment. In the last 20 years, the area of many wetlands has decreased due to the increase in industrial and agricultural development and the lack of water in arid and semi-arid regions (Cui et al., 2009). One of the effective tools in the field of wetland area changes is the use of remote sensing technology and satellite data. The use of satellite images, due to their wide spatial coverage, high resolution, low cost, temporal archive, free access to satellite images, and the availability of practical software and spectral indices, has become very important in estimating the area of aquatic zones. Monitoring and assessing the water level of wetlands using remote sensing to protect this natural heritage has become a focus for many countries in recent years, and this is of particular importance as the first step in identifying problems and attempting to solve them. Heshilan wetland plays a significant role in nourishing and increasing the stability of underground waters, preventing floods, and promoting agriculture in the region, as well as providing a unique habitat for native and migratory birds to easily pass winter. The aim of this research is to monitor changes in the water level of Heshilan wetland over a 22-year period using remote sensing and geographic information systems.

Landsat satellite images were downloaded from the United States Geological Survey website. After downloading the Landsat satellite images, the Heshilan wetland area was delineated, and the images were radiometrically and atmospherically corrected. To enhance the spatial resolution of the study area, the 30-meter pixel size image was converted to a 15-meter pixel size image for better spatial resolution (the 15-meter resolution provides more accurate information than approximate surface area estimates of wetlands), then we normalized the surface reflectance values. The Target Detection Wizard tool in ENVI 5.6 software was used to determine the aquatic zone area of the wetland in Murch of each year during (2000-2022), and the output file was imported into ArcMap 10.8.2 to calculate the aquatic zone area of Heshilan wetland in square kilometers on the date of image acquisition.

The results of interpreting satellite images over the years under study indicate that in 2018, the wetland had its lowest surface area in two decades, with an area of 0.34 square kilometers in that year. Additionally, the highest area of the aquatic zone of the wetland occurred in 2005, with an area of 3.83 square kilometers. The results show that over the past 22 years, the wetland has faced a decrease in water level by 0.79 square kilometers for the specific month.

The research results indicate that analyzing satellite images using remote sensing techniques can effectively show changes in wetland areas over time intervals. The results of interpreting satellite images over the years under study show a reduction in the extent of Heshilan wetland, especially in the western and southwestern regions, which can be attributed to natural phenomena such as drying up some springs due to droughts and periods of low water levels, as well as undesirable effects of human activities such as increased human access to wetlands through access roads in this area, land grabbing by villagers converting them into agricultural lands, deep wells around the wetlands, and utilizing wetland water through agricultural canals without considering proper water inflow. In these conditions, the wetland ecosystem has completely changed, and other aquatic birds no longer live in this area, with many migratory birds moving to tropical regions, depending on their habitats along the migration route. Given the unfavorable trends in Heshilan wetland developments, continuing the current conditions could jeopardize the existence and integrity of Heshilan wetland irreversibly. Ecosystem management of wetlands by developing a management plan to preserve and revitalize the structure and functions of this ecosystem with long-term stability can be a solution.

Soil desalination in drained fields is very important because soil salinity harms on crop yield. Therefore, for the optimal management of water and soil, and the sustainability of agricultural lands, salinity monitoring in soil is essential. In this study, 44 soil samples from the depth of 0-30 and 30-60 cm were prepared from drained lands, during one cropping year. Then, soil salinity and acidity map was produced by GPI, LPL, IDW, Ok, RBF methods. Evaluation of salinity at 0-30 cm showed that stable kriging in the first and third months, exponential kriging in the second month, RBF inverse multi-quadrant model in the fourth and fifth months, were the best models. The results 30-60 cm showed that stable kriging in the first and third month, Gaussian kriging in the second month, Exponential kriging in the fourth month, and RBF inverse multi-quadrant model in the fifth month were selected as the best model. Also, evaluation of pH at the depth of 0-30 cm showed that Spherical kriging in the first month, GPI with the first power in the second and fifth months, IDW with the second power in the third month and Exponential kriging in the fourth month had the lowest RMSE. Evaluation of pH at 30- 60 cm showed that stable kriging method in the first, third, and fourth months and GPI with the first power in the second and fifth months had the lowest RMSE. The problem of salinity and alkalinity was observed in most of the surveyed region, and the level of salinity in the surface layer of the soil was higher than in the deep layer. The comparison of the salinity map in different months shows that the salinity has been decreasing during the 5 months of monitoring and the general trend of pH changes is similar to EC.

Accurate quantification of environmental trends must consider variation at different temporal scales when ignoring variation at one scale could lead to incorrect conclusions about variation at another scale. Many environmental monitoring programs collect temporally resolved but irregular time series data to quantify trends for regulatory, management, or research purposes. Conducting a study to understand the trends and predict future conditions in hydrological aspects such as river water quality is essential. During the last decades, river water quality monitoring has increased by measuring several water quality parameters. Therefore, the analysis of water quality trends is important in providing information about changes or variations in water quality through time series data .Furthermore, determining the quality status of water resources is necessary to adopt proper policies to prevent and enhance the reduction of water quality. Additionally, based on this information, it is possible to identify the quality of river water and implement protective measures to improve and manage rivers and drainage basins in a more integrated way. In recent years, the water quality of the Karun River has been affected by various pollutants, including agricultural runoff and industrial wastewater; Therefore, it seems necessary to monitor the quality of the river and the process of its changes over time and place to know the current situation and provide the necessary measures in the future. Therefore, this research analyzed the Karun River's water quality trend over 20 years at four water quality monitoring stations.

To check the quality of river water in hydrometric stations, the obtained data were assessed from physical and chemical parameters, including Total Dissolved Solids (TDS), Electrical Conductivity (EC), Sodium adsorption ratio (SAR), Na, and Cl in 20 years from 1998 to 2017 in four hydrometric stations including Gotvand, Shushtar, Mollasani, and Ahvaz of Karun river in the wet season (first six months of the water year) and dry season (the second half of the water year). The process of river water quality and inspecting the changes were conducted using the Mann-Kendall test and a geographic information system, respectively. Wilcox's classification was used to check the water quality from an agricultural point of view, as there are relevant standards. By putting the sodium absorption ratio against salinity, Wilcox presents a chart for the water quality assessment for agricultural purposes and can classify water into different classes based on EC and SAR values.

According to the results, the river water salinity in the wet season in three hydrometric stations significantly increased. The increment was at the level of 10% at the Shushtar and Mollasani stations. However, at the Ahvaz station, it rose to the level of five percent. Due to the different annual rainfall amounts during the study period, the river water’s electrical conductivity had relatively large fluctuations in all the investigated stations. The range of electrical conductivity (EC) alterations in the wet season was between 490 and 2800 µS/cm and in the dry season between 397 and 2806 µS/cm. TDS increased in the wet and dry seasons. Moreover, the p-value showed that the value of this statistic was significant at the level of 10% in the Shushtar and Mollasani stations and at the level of five percent in the Ahvaz station. The range of changes in the wet period was between 250 and 1750 mg/liter and in the dry period between 220 and 1700 mg/liter. The alterations in total dissolved solids were more in the wet than in the dry season and did not have a uniform trend. In fact, the decrease or increase in the amount of precipitation affected the intensity and weakness of the TDS amount during the year.

The results of the Mann-Kendall test showed that the parameters of TDS, SAR, Na, Cl, and EC increased during the last twenty years, indicating the expansion of the entry of sewage and industrial and agricultural effluents. According to the Wilcox index, water quality for agricultural purposes was in the average category in all the studied stations. Meanwhile, Na, Cl, and TDS parameters were in the average and inappropriate range in some years, being an alarm regarding the low water quality. Additionally, there is a risk of water quality decline in the investigated stations. In general, the watershed of the Karun River is noteworthy due to the presence of a large population, cities, and centers. Specifically, the city of Ahvaz and the heavy steel industries located in this watershed are important fundamental in terms of water consumption and producing pollutants affecting the quality of water resources, which faces many quantitative and qualitative challenges in water. The study of the changes in the water quality parameters of the stations located in the Karun River during the study period demonstrated that the amount of dissolved salts in these rivers increased and caused the reduction of water quality due to incorrect utilization and failure to comply with the principles of river exploitation.

Given its location in the arid belt, South Khorasan Province faces an increasing demand for water due to the simultaneous growth and development of the agricultural and industrial sectors. This necessitates proper management tailored to the region's climatic conditions. Therefore, a quantitative and qualitative study of the region's water is essential for appropriate utilization and optimal management. Various indices exist to assess the quality of groundwater for drinking purposes, including GQI and WQI. In this article, a 10-year qualitative study of groundwater quality using WQI and GQI indices was conducted based on data from 29 well rings, which included parameters such as Na, Mg, Ca, Cl, SO4, TDS, HCO3, NO3, and pH. Raster maps depicting the concentration of these parameters were prepared using the Inverse Distance Weighting (IDW) method in GIS software. The GQI values for the Birjand Plain for the periods 87-90, 90-93, 93-96, and 96-97 ranged between 87-94, 85-93, 85-94, and 86-94, respectively. The WQI value for the period 87-97 ranged from 56 to 84. In conclusion, it can be inferred that the study area ranges from acceptable to suitable in terms of the GQI index, and from poor to very poor in terms of the WQI index.

Nowadays, due to the expansion of cities as well as the increase in the urban population, the lack of drinking water of good quality is always one of the most important issues for the country's water and sewage authorities, especially the people. Delivering water for consumption is one of the important activities of water transmission lines. In this context, optimizing the route of transmission lines is important. In this research, the plan to transfer water from the balance tank near Khoshab's agricultural and industrial lands and Roza Dam in Madhim City to the cities of Tabas Messina, Asadiyeh, and Gazik, has been obtained as the optimal route in terms of technical and engineering, economic and passive defense, and environment.  In this regard, the required information maps, such as topography, land use, rivers and roads, infrastructure, faults, geology, and population centers, were prepared in the form of raster maps in the GIS environment to obtain a cost map. Then, based on the Analytical Hierarchy Process (AHP), these maps were weighted and integrated, and the cost map was obtained. Finally, from the cost map, five routes were determined as the best routes, and to optimize hydraulically, these routes were entered into the EPANET software. The hydraulic design of the routes was done in this software by linking it with the multi-objective particle swarm algorithm. Two technical and economic objective functions of Pareto curves for these routes were obtained in a MATLAB environment. By analyzing these curves, route 2 out of these 5 routes has a more appropriate drop and cost and has been obtained as the optimal route for this water transfer, and this route has a length of 112 km.

The objective of the current study was to zone flood probability in the Marzdaran watershed. Since the allocated budget for management work is limited and it is not possible to carry out operations in the whole area, having a map that has prioritized different areas in terms of the probability of flood occurrence will be very useful and necessary. A well-known data mining model namely MaxEnt (ME) is applied due to its robust computational algorithm. Flood inventories are gathered through several field surveys using local information and available organizational resources, and the corresponding map is created in the geographic information system. The twelve predisposing variables are selected and the corresponding maps are generated in the geographic information system by reviewing several studies. The area under the curve (ROC) is used to evaluate the modeling results. Then, the most prone areas of flood occurrence which are prioritized for management operations are identified based on the prepared map. Based on the results, about 100 km2 of the study area is identified as the most prone area for management operations. The results showed that the accuracy of the maximum entropy model is 98% in the training phase and 95% in the validation phase. The distance from the river, drainage density, and topographic wetness index are identified as the most effective factors in the occurrence of floods, respectively.

Rice is one of the most important and popular plants that is cultivated in all six continents of the earth (Asia, Africa, Australia, Europe, North America and South America). In Iran, according to the statistics of the World Food Organization (FAO), in 2018, there were 580 thousand hectares of cultivated area and 1.99 million tons of rice production, and the import of rice in 2018 was about 1.2 million tons. Seventy percent of fresh water available in the world is consumed in the agricultural sector, of which 2 to 30 percent is dedicated to rice cultivation. Plant growth is significantly affected by climate change and subsequent water shortage. Basically, the low yield of crops is caused by deficiencies in the growing environment of plants that have not been addressed in crop management. In this regard, crop plant simulation models are used to conduct various studies, such as choosing the right plant and variety for planting, determining the best crop management, estimating regional production capacity, determining research priorities, technology transfer, classification. agricultural-ecological, predicting the effects of climate change and yield, as well as providing the basis for formulating and explaining the optimal pattern of water consumption. The ORYZA2000 model simulates the growth and development of rice plants under favorable conditions, water and nitrogen limitation. VSM model (Very Simple Model) is also a simple model for simulating plant growth and estimating product yield, which, while requiring little input information, has acceptable accuracy. Another new technology used in this direction is remote sensing. This technology can be fruitful in many agricultural decisions by predicting the performance of the plant before harvesting.

In order to evaluate the ORYZA2000 and VSM models in Golestan province, an experiment based on a randomized complete block design with three replications was conducted on Fajr rice during the 2020 and 2021 crop seasons in the suburbs of Gorgan city (Sorkhankalateh). The fields under study are located in the north of Iran with geographical coordinates of 28◦ 29' to 28◦ 32' east longitude and 40◦ 83' to 40◦ 97' north latitude with a level of 102 meters above sea level. Irrigation treatments include three levels, flood irrigation (TPR-FI) and the use of pressurized irrigation systems, including 1) band-type drip irrigation (DSR-DI) and 2) constant classic rain irrigation (DSR-SI) and compression There are three levels including D1 = 15 * 15, D2 = 20 * 20 and D3 = 30 * 30. The experimental plots of this research were considered to be 10 meters long and 5 meters wide, and the distance between the plots was equal to half a meter. In the flooded farm, after transplanting the seedlings to the intended land (June), they were kept in flooded condition until the harvest. In pressure irrigation systems, rice cultivation was carried out as dry farming and the irrigation schedule (irrigation volume) during the plant growth period was calculated using the five-year hydrological and meteorological data of the study area and the AquaCrop model. Based on this, its watering cycle was considered every other day. To evaluate the validity of the models, the root mean square error (RMSE), normalized root mean square error (RMSEn), efficiency coefficient of Nash-Sutcliffe model (NS) and explanation coefficient (R2) were used.

In this research, rice yield was estimated using ORYZA2000 model and VSM along with remote sensing technology. As seen, the recalibrated models have been successful in estimating product performance for a wide range of test data and have been able to estimate performance with acceptable accuracy. So that both models based on the values of the root mean square of the normalized error less than 10% and the efficiency of the model and the coefficient of explanation above 0.65 and the structural deviation less than 2%, have an acceptable accuracy in simulating the yield during the calibration and validation of the models. ORYZA2000 model has a higher accuracy in simulating performance than the VSM model due to the explanation factor and high efficiency of the model (0.91 and 0.84, respectively) along with the micro-scaled images with the explanation factor and efficiency of the model, It showed respectively 0.86 and 0.72. Therefore, this model has a suitable ability to estimate the yield of rice in the study area. Therefore, this model has a suitable ability to estimate the yield of rice in the study area. According to its practical results, this research can be used in the region in the coming years and the product estimation can be done based on it, which is very important in saving costs in addition to reducing the volume of field operations.

Increasing encroachment on rivers along with climate change has increased major floods. Levees are considered the most important structures to protect river banks and floodplains from flooding due to their simplicity of structure, inexpensive materials, and ease of implementation. In this research, an attempt was made to introduce a new approach in geometric modeling, to develop mathematical relationships to calculate the volumes of levees based on different location of each scenario in the floodplain. Study scenarios supply the protection of three kilometers of the Chabahar-Zahedan arterial road and its widening, which is located in the floodplain of the Karvandar River in southeastern Iran. Hydraulic simulations implemented in HEC-RAS for the existing condition and 13 different scenarios with 13 unique topographies based on the new approach, and the rate of reduction of the flood zone and embankment volume of levees for each scenario calculated in ArcMap. Based on the results, changes in the volume of embankments in different scenarios did not correlate well with the flood zone area reduction. Due to the direct dependence of scouring and thus geometry and volumes of levees on flow velocity, by calculating the flow maximum velocity in the study interval, the dimensionless coefficients of maximum velocity in different scenarios were calculated and applied to the calculated volumes of levees. Thus, by this approach and using quadratic polynomial equations, the coefficient of determination (R2) increased from 0.35, 0.48 and 0.50 to acceptable values ​​of 0.88, 0.91 and 0.92, for floods with return periods of 50, 100 and 200 years, respectively, which indicate the high efficiency of the proposed approach and also increasing in R2 values with an increase in the flood return period. Moreover, results show that the computational accuracy of regression relationships in the scenarios with levee locations in the middle distances from the road axis is higher than other scenarios which are closer or farther. This result is due to more irregular river geometry in the scenarios closer to the road and the intensification of nonlinear changes in flood parameters in the farther scenarios.

Rapid population growth, economic and social development, urbanization, and increased food demand have put pressure on freshwater resources in different regions of the world. Increasing demand for water leads to overexploitation of water resources and water shortage. Therefore, there is a need for effective alternative solutions to deal with this problem. Collecting and harvesting rainwater is one of the practical solutions to deal with water shortage. However, the selection of potential areas for the location of rainwater harvesting structures in a watershed requires the examination of several factors, including topography, land slope, soil type, rainfall intensity, land use cover, drainage, river flow, and socio-economic criteria. This shows that the planning and implementation of rainwater harvesting projects is a multi-objective and multi-criteria problem that depends on several criteria. Therefore, the integration of geographic information system (GIS) and multi-criteria decision analysis (MCDA) approaches is essential. In this research, a GIS-based model with a combination of fuzzy logic and AHP was used to determine suitable areas for the construction of rainwater harvesting structures in the Golidagh watershed for 2018. The results showed that 9.92% of the studied area has very high potential, 25.7% high, 21.58% moderate, and 42.8% poor rainwater harvesting potential. According to the findings, it is suggested to create suitable rainwater collection structures in designated places to reduce water shortage.

Maximum sprinkler flow rate, maximum irrigation interval, and leaching requirement are the primary factors in designing sprinkler irrigation systems, which are determined based on the physical and chemical properties of water and soil. This study aimed to prepare the spatial maps of the mentioned parameters in the plains of Islamabad-Gharb district, Kermanshah province. In previous studies, kriging and IDW methods have been found to be suitable for zoning the physical and chemical properties of groundwater and soil. Asadzadeh et al. (2019) investigated the spatial changes of groundwater quality indicators in Ardabil plain by kriging method to investigate the water situation in this area for irrigation systems. Yonesi et al. (2020) also zoned some critical water quality parameters (such as nitrate) of the Najafabad aquifer using the kriging method. Kumar and Sangeetha (2020) used the IDW method to classify groundwater quality in the study area and classify it according to drinking and agricultural uses. Karami and Basirat (2015) evaluated the spatial variations of some surface soil characteristics of Arsanjan plain by kriging and IDW methods. on the other hand, a specific method can not be considered the best method for intermediation and zoning of these parameters. In this study, both methods were used for mediation.

Understanding the factors, conditions of occurrence, and development of landslides in order to assess and zoning the risk of its occurrence provides the possibility of achieving methods by which the dangers and damage caused by landslides can be prevented. The purpose of this study is to prepare a landslide risk potential map with AHP and Shannon entropy models in the Cherikabad watershed of Urmia. Initially, ninety-five landslide points were recorded using GPS through field visits and Google Earth. Layers of mean annual rainfall, slope degree, slope Aspect, elevation classes, land use, Lithology, distance to River, distance to road, distance to fault, distance to village, and normalized index of vegetation difference (NDVI) As factors affecting the occurrence of landslides in the basin were selected and maps of these layers were prepared in the GIS environment and digitized. After combining the layers of factors affecting the occurrence of landslide, the landslide risk potential map was prepared for two models of Analytic hierarchy process (AHP) and Shannon entropy. The results of preparing risk maps using the Areas Under the Receiver Operating Characteristic Curve with the area below the 99% significance curve showed that both models have good performance in evaluation. Shannon entropy model with 87.9% AUC and very good performance compared to AHP model with 70.6% AUC and a good performance class, has a higher accuracy in preparing the maps. According to Shannon's entropy model, 32% of the basin is located in high and very high-risk classes, which should be considered by the relevant authorities to implement relief measures.

To determine the flow rate with different return periods, it is necessary to use the skewness coefficient with acceptable precision. Estimation of population skewness in different regions is improved by different methods such as weighted skewness and generalized skewness. The main objective of the present research is to determine the coefficients of skewness using different methods and present the best method for determining the mentioned coefficients in East Azerbaijan, Iran. East Azerbaijan has three different hydrologic regions. The north of the province is a part of Aras catchment area, the center of the province is a part of Urmia lake watershed and a part of the south of the province is a part of Sefidrood catchment area. In this research, different generalized skewness coefficients methods were used. In the present study, the generalized skewness coefficients were estimated using four methods including generalized skewness coefficient without considering hydrological regions, generalized skewness coefficient with accounting hydrological regions, unbiased skewness coefficient and weighted skewness coefficient for three hydrological regions and 62 observed stations during studied period. Based on the obtained results and on the basis of the analysis of RMSE values for different methods, the method of weighting skewness coefficient can be suggested as the selected method in East Azerbaijan with an average value of 0.104. Also, the results of calculating the Nash-Shutcliffe and the square of the mean squares of relative error coefficients showed that the weighting method is the best method for calculating the skewness coefficient.

Prioritizing different types of irrigation systems is essential for proper management of soil and water resources in the south of Ahar (9000 hectares). For this purpose, the physical and chemical properties of 44 soil profiles (soil texture, depth, lime, gypsum, salinity and alkalinity) were used and the ability of the soil to be irrigated using the limitations system as well as the suitability of the study area for the drip, sprinkler and surface irrigation systems were determined by parametric method. The application of the limitation system results showed that soil and topography were the most important limiting factors and the irrigation capacity of the study area was in classes III (arable land) and IV (limited arable land) with approximate extension of 75% and 25% respectively. Based on the results of the parametric method for surface irrigation application, only 4% of the land is classified as S1 (highly suitable) and S2 (suitable), S3 (relatively suitable), N1 (almost non-suitable) and N2 (non-suitable) with extension of about 31%, 46%, 17% and 2% in the study area. In addition, the southern parts of the area were not suitable for surface irrigation due to the high slope, and the lands for sprinkler and drip irrigation classified in S2 and S3 classes and covers 70% and 25% of the study zones and so the rest of the lands are more susceptible to sprinkler irrigation than drip ones. Based on prepared maps, about 5000 hectares of lands

In the past, human communities have always had plans for the water resources utilization and management. In the communities with water resources constraints, this type of management is more obvious. The present study is an analysis of the status of scientific products indexed in Web of Science databases in the field of sustainable water resources management. To attain this, the relationship between existing studies with effective indicators in the scientific production of this field, such as rainfall, water footprint per capita, blue water consumption per capita, green water consumption per capita and grey water consumption per capita was investigated. Information about these indices was extracted from maps drawn in ArcGIS 10.6.1. Then, the relationship between these indicators and the scientific outputs of different countries in the field of sustainable water resources management was investigated using multiple linear regression in SPSS 21 software. The results of the study showed that, the number of scientific records had a growth rate of 55% from 1800 to 2020, meaning that with the rise of the water crisis, more scientific studies have been conducted on sustainable water resources management. Secondly, the US, China and India have most scientific papers in this field. The results of regression analysis of the effective indicators showed that an increasing in annual rainfall also blue water and grey water consumption per capita has an important role in increasing scientific production in the field of sustainable water resources management.

Water, as a major limiting factor in production, plays an important role in determining the type of agricultural activities in Iran. The occurrence of droughts in recent decades have also threatened these activities. Today, one of the most effective responses and strategies for agricultural drought risk management is to identify vulnerable areas and determine the optimal pattern of low-water cultivation. Therefore, the aim of this study is spatial analysis of agricultural drought vulnerability and introduce a pattern of low-water cultivation and compatible with arid areas in Pishkuh watershed in Yazd province. In this research, first the dominant garden species in the study area were identified and after calculating their water requirements, a map of the agricultural drought vulnerability in the study area was prepared. The results showed that the southern to southwestern of study area, including the villages of Sanich, Darreh Shir, Darreh Sir, etc., have the highest vulnerability to drought compared to other areas. Therefore, it is recommended to be cultivated garden species with the least water requirement such as almond and Grapes with water needs of 753 and 798 mm during the growing period, respectively. Also Results showed that the central, eastern, and northwestern of study area, including Islamieh, Navab, Nasrabad villages and etc., have a moderate and relatively low vulnerability. In addition, it is recommended to plant the species with moderate-water needs such as pomegranate and apricot. Therefore, changing and modifying the cultivation pattern, such as reducing the planting areas with high water requirements, developing species with low water needs, and increasing water efficiency, is one of the most necessary activities for managing agricultural drought risk.

Nowadays, one of the main problems of water resources in the country is the decline of water resources quality. The increasing demand for water has led to untapped groundwater exploitation and constant water loss in aquifers and as a result environmental problems including the quality of groundwater have been endangered and have created a destructive process. In this study,using the collected data from Neyshabour plain , relationship between groundwater level and increase salinity was determined. In order to investigate the quantity and quality of groundwater in the Neyshabour plain, using the data of surface water level and electrical conductivity, the map of changes in the water level and the qualitative variables were determined in the ArcGIS 10.2 software using a Geostatistics method. The results of the spatial zonation mapping of the quantity and quality of groundwater in wells showed that the water level decreased with the passage of time in the specified period and consequently its amount quality decreased.

Sewage collection network is one of the largest and most valuable infrastructure assets. Therefore, managing the wastewater collection network faces many challenges. Unfortunately, due to the extent of the damaged wastewater collection network and time and budget constraints, it is not possible in practice to treat and eliminate all wastewater collection system damages at the same time. So, this issue requires management activities in the form of vulnerability rating, to develop a maintenance program for sewage collection system maintenance. The present study evaluated and ranked the vulnerability of the sewerage network implemented in a part of District 5 of Tehran Municipality using a combination of Analytic Hierarchy Process (AHP) and GIS technique. AHP is one of the most efficient multi-criteria decision-making techniques, in this method, the factors are compared with each other in pairs and the highest weight is given to the layer that has the maximum effect on goal setting. In this regard, according to the opinion of experts and literature review, all types of possible damage to the sewage collection network at three levels of manhole, pipeline and branch were investigated and classified. In order to determine the relative importance of the defects, a questionnaire was prepared and distributed amongst experts working in the field of design and maintenance of sewage systems. Using AHP method, pairwise comparison between the relevant factors was performed and the relative weight of each criterion was calculated. After calculating the inconsistency ratio and confirming the meaningfulness of the judgement matrices of effective factors, the final weight of each criterion was applied to the corresponding layers to prepare the zoning map of the area. Next, judgement matrices were transferred to ArcGIS software and raster output was generated from them. The raster layers of different factors in ArcGIS software were homogenized and then combined using Fuzzy Membership method. In fact, the ultimate goal of the GIS technique used in this study was to obtaine the final overlap of all factors affecting the vulnerability of the sewage collection network (at two levels of manhole and pipeline clogging) and provide a zoning map of damages in the study network. It is important to note that the transformed raster maps for each of the effective factors have different units that must be scaled to the fuzzy membership method. As a result, all values scaled between 0 and 1 range. In general, each number in this range indicates the strength of membership in a set, based on a specific fuzzy algorithm. Next, the Fuzzy Membership command was run to obtain fuzzy the classified raster, from the Spatial Analyst Tools toolbox and the Overlay menu. Thus, fuzzy raster of quantitative criteria affecting the vulnerability of the sewage collection network was obtained. Weighted Overlay method was used to correctly apply the resulted weights and present the final model in ArcGIS. Thus, the fuzzy raster was added to the Spatial Analyst Tools toolbox and the Overlay menu, using the Weighted Sum command. Then, the aggregation of the obtained weights revealed the total weight of each of the target factors. Finally, the vulnerability zoning map of the sewage collection network was prepared in two levels of manhole and pipeline. According to the results, the probability of failure of the implemented manholes was very low and more than 70% of the manholes were classified in the category of low and very low damage. One of the possible reasons for this could be the young age and the principled implementation of the sewage collection network. The final overlap of the factors and sub-criteria affecting the vulnerability of the sewerage network indicated that the probability of destruction of pipelines was very low. More than 74% of the sewerage collection pipeline implemented in the case study area was classified in the category of low and medium damage. The results showed that only 30 wastewater transfer pipelines (about 7% of the whole network) were in critical conditions that should be given more attention. It could be considered that the small number of critical pipelines was due to the short life of the implemented pipelines. Based on the results, among the three target factors (manhole, pipeline and branch), the highest vulnerability of the sewerage collection network was related to the pipeline blockage. Also, the defects of the operational defects in all three levels of manhole, pipeline and branch clogging was the most affecting factor and have the highest impact.