فهرست مطالب mahmoud habibnejad roshan

Floods are one of the most destructive natural disasters that cause severe injuries and loss of life, major infrastructure damage, significant economic losses, and social unrest worldwide. Due to the fact that flood is a dynamic and multidimensional phenomenon, Geographic Information System (GIS) and Remote Sensing (RS) data are used to a large extent to discover the extent of flooded areas and play a special role in preparing flood risk and susceptibility maps. Flood susceptibility mapping is essential for characterizing flood risk areas and planning flood control schemes.

In this research, the identification of flooded areas in the Karun Watershed based on the Analytical Hierarchy Process (AHP) in the GIS environment and its validation with the NDWI blue index extracted from Landsat 8 satellite images has been considered. For this purpose, first, 15 effective parameters in floods occurrence including slope, aspect, elevation, curvature, rainfall, distance from stream, stream density, distance from fault, fault density, distance from road, road density, lithology, Curve Number (CN), land use, Topographic Wetness Index (TWI) and Stream Power Index (SPI) were selected and the weighting of these parameters was done based on AHP method in the Expert Choice software environment. Finally, by using the command to combine the layers based on the weighting of the AHP method in GIS, the final flood risk zoning map was obtained. NDWI water index was used to validate the flood risk map obtained.

The results of the AHP model showed that the most effective factors in the occurrence of flood risk in the Karun Watershed include rainfall, the amount of slope and the height classes, which should be considered in order to reduce flood damage and provide management solutions for these factors. Also, the results show that the downstream areas of the watershed have the highest risk of flooding and more than half of the watershed's surface (52.24%) has a medium flood potential.

Preparing a map of flood-prone areas is one of the most constructive methods that enable the reduction of flood risk damages and help planners, stakeholders and decision-makers to properly monitor flood-prone areas and ensure appropriate and sustainable socio-economic development.

Many of the environmental problems are caused by the changes in the main components of the hydrological cycle. However, water balance modeling can help to better understanding the components of the hydrological cycle in order to develop appropriate management options. The purpose of this study is to calculate three important components of surface water balance using the WetSpass model and evaluate the model in Hamadan-Bahar Watershed located in Hamadan Province on a monthly time scale. The results of the model evaluation in the study showed that the coefficient of determination between the observed and simulated runoff in the calibration and validation period is equal to 0.79 and 0.83, respectively. Groundwater nutrition assessment was also performed according to manual calculations of the variable for 2012-2013. Then, the results of Kramer correlation coefficient between spatial distribution maps of runoff, actual evapotranspiration and groundwater recharge were investigated with input maps of the model. In general, due to the importance of evapotranspiration in water balance calculations, the evaporation and transpiration maps of the model were evaluated separately for different uses. The evaluation results confirmed the capability of the WetSpass model in simulating runoff, evapotranspiration and groundwater feeding with an acceptable accuracy. The results of spatial distribution maps of runoff, actual evapotranspiration and groundwater recharge indicate a high correlation between evapotranspiration component with land use (0.54), soil texture (0.45), evapotranspiration potential (0.42) and temperature (0.31). Also, these results indicate a high correlation between runoff components with land use (0.62) and soil texture (0.58), and average correlations between groundwater recharge component with land use (0.32) and soil texture (0.34). Therefore, land use and soil texture were the first and second factors affecting the distribution of surface balance components, respectively.

Background and Objective:

 North Karun watershed is one of the important sub-basins of the Great Karun River basin. In recent years, the occurrence of severe downstream floods in this basin has caused a lot of human and financial losses. Estimating the amount of runoff produced by rainfall is the main step in conducting a study on flood control and mitigation. Runoff estimation is one of the most important steps in the study of watershed hydrology for flood management, water resources management and soil conservation activities. Runoff is produced as a result of excess rainfall on soil infiltration and surface maintenance and depends on various factors such as physical characteristics of the basin, rainfall and infiltration. The rainfall-runoff relationship has been studied by scientists and researchers and many models have been proposed to simulate this process. One of the basic models in this field is the curved number method model that was proposed by the US Soil Conservation Service and was named the Soil Conservation Service Curve Number or SCS-CN. The SCS-CN model is one of the simple and empirical models in the field of rainfall-runoff that is widely used in estimating runoff height around the world. The curve number (CN) of each basin indicates the hydrological behaviour and runoff generation capacity of that basin during rainfall and its value is estimated from the standard table in which the soil properties with a hydrological factor that indicates the minimum infiltration rate in the long-wet state. It is the duration of the soil, it is expressed. Accordingly, the US Soil Conservation Service has divided all soils into four main groups, A, B, C and D, with high, medium, low and very low infiltration rates, respectively. Due to the high time consumed in calculating this method, traditionally and manually, researchers used remote sensing and geographical information systems technologies to calculate it. To do this, they designed an extension called ArcCN-Runoff that can be added to the GIS environment. The purpose of this study is to generate a curve mapping (CN) and estimate the runoff height in the North Karun Basin using Remote Sensing (RS) and Geographic Information System (GIS) technologies and the SCS-CN method.

Materials and Methods:

 North Karun watershed is one of the most important watersheds in the country in providing water resources, which is located in the geographical position of 49o 35' to 51o 47' E longitude and 30 o 28' to 32 o 40' N latitude. This basin has an area of 23299.31 Km2, which is located in Kohgiluyeh and Boyer-Ahmad, Chaharmahal and Bakhtiari, Isfahan, Khuzestan and part of Fars province. In order to produce curve number maps and estimate runoff height, first land use maps were generated using a supervised classification method using Landsat 8 satellite images of OLI sensors related to 2017 and the maximum likelihood algorithm was obtained. Then, the soil layer and soil hydrological groups of the basin were prepared based on the global soil map produced by the Food and Agriculture Organization (FAO) and the SCS standard table for different soil hydrological groups. By combining land use maps and soil hydrological groups with the Perform Intersect command in the ArcCN-Runoff GIS environment, a curved number (CN) map was generated and edited and finalized based on the SCS-CN table. Finally, by generating a spatial distribution map of precipitation by IDW method at the basin level, runoff height or excess precipitation height was obtained by the SCS-CN method. The final runoff height map was divided into five categories: very low, low, medium, high and very high.

Results and Discussion :

The results showed that a large area of the basin has a slope of more than 30%. Slope can be considered the most important physiographic factor in runoff production in watersheds. According to the land use map, the highest level of use is related to the oak forests of Zagros and rangelands. Due to the type of oak forests that have low density and also poor pastures in the basin due to overgrazing, runoff production is high in these uses. The curve number map also indicates that the maximum and minimum curve number values are in basins 98 and zero. In areas with high curve numbers, the potential for runoff production is high and these areas are related to areas with poor vegetation in the basin. Areas with high curve numbers and high runoff production are mostly related to the calcareous formations of the basin, including the Bakhtiari and Asmari formations, which have formed the high altitudes of the basin, including the Dena Mountains. Also, areas with medium and low CN are mostly related to forest and pasture uses, in which the potential for runoff production is moderate. On the other hand, due to the fact that most of the precipitation in the basin heights is snow, there is an opportunity to penetrate into the soil and as a result, the amount of runoff production is less. The calcareous formations in the basin, which form most of the Zagros highlands, penetrate rainfall through pores and fractures and feed groundwater, which is why we often encounter a large number of springs in these areas. On the other hand, the results of the runoff map indicate that the Zagros heights, which have a high slope, play a major role in runoff production. These areas are mostly located in the southern and southeastern areas of the basin, as well as northwest of the basin.

Conclusion :

A large area of the basin has the potential to produce moderate runoff, which can lead to flooding downstream of the basin. Therefore, it is necessary to implement conservation and watershed management measures in the branches and areas where the flow occurred. Due to the fact that the basis of calculations in preparing maps of curve number and runoff height are raster layers, each pixel of which has a value, the calculations are done and the results are much closer to reality and save time and money.

 Floods are one of the most catastrophic and dangerous natural hazards because they are sudden and unpredictable and lead to the destruction of infrastructure, and a threat to human life and property. Identifying areas with high flood potential is one of the most important tasks in flood control and reducing the damage caused by it. Floods are one of the most serious natural hazards that pose serious threats to residential areas and also pose financial and human risks. Floods rank first in terms of damage caused by earthquakes, volcanoes, and landslides. Cited. Floods can occur not only in the plains but also in mountainous environments. Flood analysis and its relationship to explanatory variables can help water managers identify the most effective variable in floods. Communities, countries, and pcontinents have suffered severe human losses and economic costs due to the increasing severity and frequency of these natural disasters). In the world due to the increase of these natural disasters, human death in the coming period is probably doubled. Floods are one of the most serious natural hazards that pose a serious threat to residential areas. Climate change and the steady increase in urbanization that occurs with increasing population, followed by an increase in man-made structures, ultimately reduce permeability and possibly further increase the risk of floods and the potential for socio-economic damage. Confirming the growing risks and increasing frequency of flood events, a paradigm shift in flood risk management is observed in many countries, such as Europe. Flood management and mitigation require comprehensive perspectives that take into account a diverse set of flood risk management measures, including active stakeholder engagement, communication, and awareness raising. The present study was conducted in the Neka Rud watershed in Mazandaran province. The use of geographical systems can identify flood-sensitive areas with high accuracy in the shortest time using information layers. This watershed is one of the most important watersheds in the province and its study is of great importance in terms of flood risks due to its high rainfall. Enjoys. The overall purpose of this study is to prioritize sub-basins concerning flooding based on morphological analysis and also to use GIS software as an efficient and cost-effective tool. In this study, the morphometric study of the watershed was investigated and flood sub-basins were identified. The purpose of this study is to identify areas with high flood potential in the Neka River watershed of Mazandaran province to prevent the risks of this natural disaster and prevent financial and human damage.

 Seventeen Morphometric parameters were determined to describe the watershed and prioritize the sub-basins of the Neka watershed according to the sensitivity to sudden floods. The basic parameters were measured directly from the DEM using GIS techniques and include basin area, basin length, environment, number of streams, and flow lengths for each flow rating. In this study, very important morphometric parameters were quantitatively selected and used for this analysis. These parameters are directly or inversely related to runoff hazards, peak discharge, and soil erosion. These parameters were divided into three parts: linear, uneven, and surface. Finally, sub-basins were prioritized using this method. To assess the morphology of the watershed, a digital elevation map (DEM) with a resolution of 12.5 m was loaded. Morphological parameters are directly or inversely related to the outbreak. After morphological ranking, the values of each sub-basin were collected to classify and determine their susceptibility to flash floods. The values of the sum of morphometric parameters summarized from 0 for the lowest rank value and 1 for the highest rank value to obtain the flood sensitivity index for each sub-basin were normalized and finally evaluated. Clear changes are observed in the basic parameters of watersheds such as area, environment, and length of the basin. These basin parameters are a very remarkable hydrological feature. The watershed area varies from 484.37 square kilometers under the N1 basin to 48.18 km2 under the N8 basin. The environment can also be used as an indicator of the shape and size of the watershed. According to the obtained results, there is a high correlation between the area and the watershed environment.

The Neka Basin was divided into 12 sub-basins using the Hydrology Toolbox from ArcGIS. According to the obtained results, it was found that sub-basins N8 and N9 have a high priority for flooding. The results show that these two sub-basins are very prone to flooding. Also, sub-basins N11 and N12 have a much lower risk of flooding. The total number of 12 sub-basin flows for the watershed is 366681 and for the first time, it constitutes 52% of the total watershed flows. Geometric values for 12 watersheds are shown in the form of a graph and a straight line, where the log values of the flow number are plotted on a graph.

Because there are insufficient historical climatic and hydrological records for hydrological modeling, morphometric analysis has been used to assess sub-watershed susceptibility to flooding. The results and analysis obtained in the present study have several fields for practical application and future development. Morphometric analysis of the Neka basin has shown that the watershed is a six-stage drainage system that is very sensitive to flooding. According to the results, sub-basins N8 and N9 have a high risk of flooding. In contrast, the N12 sub-basin has a much lower rate of flooding. The study of the basin showed that the reason for the low flooding below the N12 basin is the shape of the basin and the amount of slope, which has an elongated shape and the area is almost flat in terms of unevenness, which reduces the risk of floods. This study showed that the protection of the region against sudden floods should be the main priority of the competent authorities to protect human lives and agricultural farms and ultimately prevent flood disasters. In this study, it was proved that integration and morphological analysis with GIS can provide a significant tool for understanding the characteristics of watershed sub-basins related to flood management.

The aim of this study is to select the effective parameter and optimum combination for R-R modeling using Gamma in WinGamma for Northern Karun watershed. daily precipitation and discharge data in 1997-2017 was used. Lake data was removed and homogeny of data done using Run-Test. Statistical corrections were corrected by correlation method and data homogeneity test was performed by Run-Test method. The coefficients of auto-correlation, partial auto-correlation and cross-correlation in the R Studio software environment were used. Optimum inputs were also obtained using the Gamma test in WinGamma . The results showed that 9 optimum input include precipitation today (Pt), one day (Pt-1), two days (Pt-2), three days (Pt-3) and four days (Pt- 4), As well as discharge the day before (Qt-1), discharge with a delay of two days (Qt-2), three days (Qt-3) and four days (Qt-4) had a significant level of confidence at the level of 5%, which for the creation of 130 suitable combinations was identified and based on the lowest Gamma (Γ) statistics, a suitable composition was determined for each sub-watershed. for the whole basin, the optimum inputs include the parameters Pt, Pt-1, Qt-1, Qt-2 and Qt-4, and the best combinations are Pt, Pt-1, Qt-1, Qt-2, Qt-3. In general, in all sub-watersheds and the whole watershed precipitation of the current day, the precipitation of one or two days ago as well as the discharge of the previous day and two days ago have a significant effect on the runoff entering the in river basin.

Preparing a flood susceptibility map is necessary and the first step in reducing the damage caused by floods. Due to a lack of information in most of the basins, many researches uses data mining techniques for hydrological studies, especially floods. The aim study is to identify areas with flood susceptibility using a support vector machine (SVM) in the Nekaroud basin. For this purpose, 12 geomorphologic, hydrological and physiographic parameters including slope, aspect, elevation classes, temperature, land use, rainfall, density and distance from the fault, density and distance from the drainages, density and distance from the road, which are provided in the ArcGIS,  SAGA GIS and ENVI software’s environments. The GPS device was also used to acquire flood points. Finally, all variables and flood points were entered into the R software in ASCII format with the same pixel size (12.5 m). To evaluate model accuracy, ROC was used in the R software environment. The results of the evaluation showed that the SVM model has good accuracy in identifying flood susceptibility areas in the study area. In addition, the results of this study showed that flood susceptibility areas are more in the northern and northwest regions of the basin and in portions where the concentration of human settlements is higher, while the central regions of the basin with dense vegetation have a low sensitivity to flooding. The results of this study can help planners and researchers to do appropriate actions to prevent and reduce future flood risks. It can also be used to identify suitable and safe areas for construction development.

River flow simulation has particular importance to be aware of the river flow and determining flood discharges in the future periods. Different hydrologic processes such as interception, surface depression storage, infiltration, soil storage, percolation, and groundwater storage would be considered in continuous hydrologic modeling. Considering the different methods of hydrological simulation, continuous simulation has a best prediction because of the dry and wet conditions modeling during the long-term period. HEC-HMS model uses Soil Moisture Accounting (SMA) algorithm to simulate the long-term relationship between rainfall, runoff, storage, evapotranspiration, and soil losses. In this study, soil moisture accounting model (HMS SMA) was applied to determine the effect of soil moisture on runoff generation, evaluating of flows simulated, in the Zaremrod watershed, Mazandaran province.  Daily R-R data (4 years, from 2006 to 2010) and monthly evapotranspiration data, Digital Elevation Model (DEM-25m) and the drainage network map were used for the calibration and validation of model. The results of simulation revealed that monthly scale with maximum value of the determination coefficient and Nash–Sutcliffe efficiency and minimum mean absolute error and root-mean-square error manifested the most accurate simulation in the calibration and validation. Generally Results of the research showed capability of HEC-HMS model with new model for losses calculation (SMA) for river flow simulation in the Zaremrod watershed.

Reducing the groundwater level due to irregular exploitation of these resources has caused land subsidence in most plains of our country. Study of this reduction in the groundwater level and trend of changes is essential for groundwater resources management and prevent adverse effects of irregular exploitation. In this paper, the indices of groundwater resource index (GRI) and the water level standardized (SWI) as two important index in hydrological drought were studied. To this goal, data from 40 pizometric wells located in Sari – Neka plain was used during the period of 30 years. In this study, first indicators of GRI and SWI in a year using the existing relations in the software Minitab 17 and M.S. Excel 2016 were calculated. And then, Using Mann - Kendall and Sen's slops in the application environment Makesens trends were examined. The results showed that both indices at the level of 99% has been declining and drought severity based on these two indicators has increased with time. As the drought severity in two indices for annual scale in 1394 and best wet for two indices for 1369, The main reason for the increase is the number of wells in operation, resulting in irregular exploitation of groundwater resources for agriculture in plain.

Iran has an arid and semi-arid climate as well as a more unstable ecosystem than humid regions; so the importance of water and soil resources conservation becomes higher in this country. The use of vegetative buffer strips is an effective strategy to reduce pollutions in surface waters as well as soil erosion. The present research has been conducted with the aim of study the effect of runoff rate, plant age and plant species on the efficiency of vegetative buffer strips to control runoff quality and quantity in Sari, Mazandaran, Iran. 1×10 m experimental plots were used and artificial runoff with two rates equal to the runoff generated by a precipitation with 25 and 100 years return period. The results indicated that the efficiency of vegetative buffer strips containing vetiver grass and turf grass affected by the runoff with a rate equal to the runoff generated by a precipitation with 25 years return period was higher than the buffer strips affected by the runoff with a rate equal to the runoff generated by a precipitation with 100 years return period, during the study period. Also, it was found that the efficiency of vegetative buffer strips to control runoff quality and quantity is affected more by the flow properties than characteristics of buffer strips, their plant age and species, when runoff rate is high. Two studied plant species including vetiver grass and native turf grass also showed a different performance to reduce runoff volume and its pollutants. On the other hand, variation of the plants’ age caused different efficiency for the studied vegetative buffer strips.

Integrated watershed management and regeneralization of available information to ungauged basin needs to recognize homogeneous watersheds. The hydrologic similarity of watersheds is caused by the hydroclimate and physical behaviors. In present study, hydroclimate and physical indices were used for indicating the homogeneous sub-watersheds in Karkheh Watershed and then results were compared. Factor analysis to reduce in the dimension of variables was conducted, separately for climatic, hydrological and physical parameters. Finally, using Fuzzy c-means (FCM) and hierarchical clustering analysis (HCA) homogeneous sub- watersheds were indicated by hydro-climate and physical parameters. Factor analysis results showed that indices of CSDI (cold spell duration index), GSL (growing season length), RX5day (monthly maximum consecutive 5-day precipitation), TX90p (percentage of days when daily maximum temperature is greater than 90th percentile) and TMAXmean (mean of maximum temperature) of climate indices, and indices of percent of hydrologica group D and flood potential index of hydrologic indices were selected. Also indices of basin area, basin elongation, average length of drainage and total topography between the physical parameters were selected. Comparing the results of the FCM and HCA indicated that the optimal number of clusters is same, but the results of watershed classification are not same in each cluster of two ways. Classification by hydroclimate and physical indices highlights that 25 and 27 basins were classified similar, respectively in two methods of clustering. Clustering by hydroclimate parameters produced different results compared with physical parameters, so that the 17 and 19 sub-basins are in the same classes in the FCM and HCA, respectively. However, there is no preference to accept watershed classification by hydroclimate or physical parameters, thus a combination of hydroclimate and physical parameters were used for classification. Watershed classification by the combination of hydroclimate and physical parameters indicated that 33 sub-basins were classified similar in both FCM and HCA methods. Classification in Karkheh basins based on the combination of physical and hydroclimate parameters revealed that the northern areas are in group 3, central regions (from east to west) are in group 2 and southern areas are in group 1. Inherently, these basins are similar in each group and demand the same protection operations in view of watershed management.

Management of watersheds requires understanding of watershed conditions both in gauged and ungaugedbasins. The classification of watersheds by similarcharacteristics for the implementation of coordinated watershed operations and flood control as well as giving priority to sub-basinsis of great importance. The need for a classification framework in hydrology is not an entirely new subject. In fact, this subject has long been discussed and several studies have also attempted to advance this idea. So far, no acceptedcomprehensive protocol has been presented for the classification of watersheds,and questions can be raised regarding why this has not happened. More efforts must be made in order to develop such a classification.Previous studies have used hard clustering methods more, for the classification of watersheds but, the present study used fuzzy approach as asoft method. In general, the purpose of this research is to focus on the characteristics of the watersheds including morphological characteristics, soil and land use for the identification of similar watersheds. These parameters can facilitate the watershed classification scheme and our understanding ofthe watershed conditions. The dataset for this study includes is base maps (sub-watersheds boundary, streams and rivers, digital elevation model (DEM), soil and landuse which have been collected from Iran Water Resources Management Company. To classify the Karkheh watershed, 35 spatio-physical indices including topographic, morphological, landuse characteristics and soil parameters were considered. These indices have been calculated for each watershed. The dimension reduction of the variables was an important part, because 35 indices were quite large for the classification of 38 watersheds. Therefore, factor analysis for each group of indices wasusedseparately to reduce the number of variables.
After reducing the variables and selecting the final indices, the fuzzy clustering approach was conducted to classify the watersheds into homogenous groups. The number of optimal clusterswas determined through trial and error and the functions of partition coefficient and partition entropy evaluation. Kaiser-Meyer-Olkin (KMO) test statistics for each group of the morphological, landuse and soil indices were 0.71, 0.69 and 0.76 respectively, indicating that the data was suitable for factor analysis. Factor analysis was conducted using Principle Component Analysis (PCA) method and the results revealed that among 35 spatio-physical indices, 9 indices (4 morphological indices, 3 land use indices and 2 soil parameters) had a higher load factor than other indices. Therefore, indices of the watershed surface, basin elongation, average length of drainage network and total topographic indexamong the morphological indices;percentage indices of rangelands, agricultural lands and wastelandsamong the land use indices; and indices of water holding capacity in the soil layer and saturated hydraulic conductivity among the soil parameters were selected as the ultimate criteria for grouping the watersheds.
Theselectedfactors were normalized between zero and one before the classification. Then, sub-watersheds were classified using fuzzy C-mean (FCM) approach. The trial and error method was used to find thenumber of optimum clusters. The maximum amount of evaluation function of partition coefficient equal to 0.76 and the minimum amount of partition entropy function equal to 0.49 occurred in three clusterstherefore,the number of optimum clusters equal to 3 clusters was determined through trial and error.The results of classification indicated that the triple groups included the sub-watersheds of the northeastern regions and parts of central regions of the Karkheh watershed (group 1), the northwestern- southeasternalong with the southern regions of Karkheh watershed (group 2) and the central regions and parts of southwestern regions of Karkheh watershed (group 3). Watershed classification with similar characteristics can be used as a method for watershed management, flood control and giving the priority to critical sub-basins. However, watershed classification is only completedwhenit is understood why some catchments belong to certain groups of hydrological behavior, so as to be possible to classify gauged and ungaugedwatersheds through it.
Finally, it is important to remember that classification of watersheds is not the “be-all and end-all” of research on watersheds, but rather only a means towards achieving broader aims of planning and management of our ecosystems, environment, water resources, and other relevant earth systems and resources. However, watershed classification certainly allows us to study catchments more effectively and efficiently and develop more appropriate strategies in terms of simplification in models/model development, generalization in our modeling approach, and improvement in communication both within the hydrologic community and across disciplines, as much as possible.

Decrease of aquifer recharge, Increased pumping through deep wells for agricultural purposes, increases in temperature and evapotranspiration, climate change and change the type of precipitation induced reduce of water level and water table which is called Groundwater Drought. Identifying, monitoring and characterization of drought is very important for water resources planning. The object of this study is investigating temporal and spatial variations of groundwater drought using Groundwater Resource Index (GRI) and Standardized Water Level Index (SWI) in the plain area of Sari-Neka. For this purpose, groundwater data of 40 piezometric well from 1364 to 1394 were analyzed. Thus, GRI and SWI indices for time scales of 3, 6, 9, 12, 18, 24 and 48 months in Minitab and M.S Excel was calculated. Spatial extent of groundwater drought in the plain using IDW in ArcMap 10.3 was obtained. The results show that the severest drought in 3-month time scale using GRI index in Shahrivar 1394 in the amount of -93.3 and SWI index in Mehr 1394, with value of 86.4 occurred. Drought spatial changes in northern parts of the plain are related to Mordad 1384. Zoning maps indicated that Mordad highest amount of drought and Bahman has lowest value; the most important for this is pumping water from groundwater aquifers for agriculture.

Water, along with issues such as preserving the environment and eradicating poverty and hunger, is a fundamental issue in sustainable development and is an essential element of human survival and well-being. The lack of water in the arid and semi-arid regions of the world has caused the environmental conditions to be fragile. Therefore, the purpose of this research is to identify areas susceptible to rainwater harvesting in order to rehabilitate water resources in different ecosystems using a hierarchical decision making method based on spatial analysis in the GIS environment.
In this research, the factors affecting rainwater penetration and storage in the soil profile of the Ghiran and Khosrowabad watersheds of the city of Sangar, Kermanshah Province, were identified and entered the hierarchical analysis process. At first, by using expert opinions, relevant faculty members and experts, by means of paired comparison and in accordance with the method of time, the tables of value were completed and then analyzed by special vector method. For each matrix, the result of the division of the inconsistency index into the random matrix inconsistency matrix, then the matrix, is a suitable criterion for judging the incompatibility, which is called incompatibility rate. If this number is less than 0.1, the system compatibility is acceptable. Then, their importance coefficients were determined and the paired comparison tables completed. In this regard, the weight of 11 variables of vegetation, canopy, percentage and direction of gradient, rainfall, lithology, land use, soil hydrologic groups, geomorphology, elevation and erosion classes were calculated using MATLABR2009a software and based on the ArcGIS10.3 environment. Which were respectively 0188/0, 0254/0, 1365/0, 048/0, 2509/0, 0608/0, 0575/0, 1539/0, 0589/0, 0808/0, 1084/0 Came out. After determining the weight of each of these criteria, the susceptible areas of rainwater storage were identified and in the GIS environment, five levels were classified as very suitable, appropriate, moderate, unsuitable, and unsuitable, respectively, for the areas of beer and Khosrowabad, respectively (% 33, 32/41, 46/8, 47/7 and 47/5, 08/41, 53/37, 31/8, and 64/5 of the area of ​​the basin. 59 benchmarks were expressed in general, of which 11 were the main criteria and 48 sub-criteria were considered. The selected indicators were used by the questionnaire and by experts, experts and experienced experts by group method during the process of engineering value and Individual and comparative method was double-valued. Tables (1 to 9) show the results of pairwise comparison of the parameters and weights obtained after the formation of a pair comparison matrix. In the AHP method, the criteria are first qualitatively and then are presented quantitatively using the table. In this process, the ratio of incompatibility is determined and if its value is less than 0.1, then there is an indication of the acceptable level of compatibility of the pairwise comparisons. In this study, the degree of inconsistency for each of the main criteria and its sub-criteria is indicated separately in the tables below given.
The results of this study showed that, in addition to the rainfall factor which is the main factor, two slope factors and soil hydrological groups as the other main factors for collecting rainwater from the rest of the factors have more and more impact. According to the results obtained and the tables shown, the lowest inconsistency rate related to the gradient direction, which is equal to 0.123 (Table 8), and the highest is related to erosion, which is equal to 0906 (Table 1). The results also showed that slopes of 20-30%, which are mostly pasture and pastures, are suitable places for storing runoff. Areas with Ptanicyle have a very good harvest area that is best suited to store atmospheric precipitation in terms of coverage, slope and permeability. According to the obtained map of Figure 2, the total area of Khosrow Abad watershed (1819.68 hectares) has a total of 26.26 hectares, has a very suitable potential, 769.79 hectares suitable, 696.59 hectares average, 154.27 hectares inappropriate and 77/104 hectares are very inappropriate for collecting rainwater.
Discussion and The results of this study indicate that the method used has high credibility in zoning the suitable areas for implementing rainwater harvesting projects and using the process of analyzing hierarchy in the GIS environment as an effective spatial decision system in the location of areas susceptible to rainwater harvesting.

This study aimed to evaluate the temporal change and accuracy of interpolation techniques used for spatial zonation of two groundwater quantity parameters including water table and depth to water table over 11 years. The study was conducted based on the data collected from piezometric wells of Sari-Neka Plain in Mazandaran Province, Iran. The investigated methods included a set of geostatistical approaches involving simple Kriging, ordinary Kriging, Radial Basis Function (RBF), and a deterministic interpolation method called Inverse Distance Weighting (IDW) with powers of 1 and 5. Subsequent to quality control and data normalization, the most appropriate variogram was chosen based on low RSS and high r2 while the most suitable interpolation technique was determined regarding the cross validation, Mean Absolute Error (MAE), and Mean Bias Error (MBE). The results demonstrated that Simple Kriging was the most suitable method for zoning the depth to groundwater over the years 2001, 2006, and 2012. Meanwhile, the most suitable methods for zoning the water table included IDW with a power of 1for the year 2001, RBF for the year 2006, and IDW with a power of 5 for the year 2012. The important finding was that the interpolation methods showed a lower error for estimating water table than estimating depth to groundwater. This study also revealed a drop in water table in the study area over the 11 years’ period. Meanwhile, new water table classes have been added and extended between the years 2006 and 2012 that had not existed five years earlier. The highest water table losses were observed in three points at 13m depth to water table in the middle and northern parts of the study area.

To analyze surface water quality in the Haraz River, 12 water quality variables accompanied by hydro-climatologic parameters analyzed by Mann-Kendall Non-parametric test during the period of 1991-2015. To detect probable effects of land use changes, these changes also analyzed by GIS in 1991, 2006 and 2015 years. The results showed that most of time series of water quality have significant increasing trend that represents severe reduction in water quality of Haraz river. According to the results of Mann-Kendall test (trend analysis of hydro-climatic parameters, detection of abrupt change point and Kendall τ correlation test) and also land use changes trend, it was concluded that both climatic and land use change can be effective on reducing the quality of water resources so that temperature increase and precipitation decrease on one hand can be led to decrease of some parameters such as Ca2, HCO3- and TH, and on the other hand, these changes together with land use changes can be the main reason of increase in most of parameters such as TDS, EC, Na, Cl-, SAR etc.

Climatic parameters in time and space scales of change are for many reasons of Changes and how they should be based on observations using a statistical method to be determined. Analysis of the most widely used statistical methods that assess potential climate change on hydrological time series, such series of precipitation, temperature and flow rate used. This study of 11 synoptic,rain gage and climatology stations with 30 years during the years 1979 to 2009 period is Charmahal o Bakhtiari province.Mann-Kendall non-parametric and  sen estimate tests were used for the purpose of the study.The results showed that 11 stations were the only station in sepid dasht 95 and 99 percent had significant levels decline and changes in the slope is negative and other gage stations does not have significant trends. The results of this study can be in the long-term planning for water resources management, irrigation scheduling and prediction of future droughts in the province can be used

The study of drought has important significance in water resources studies. Meteorological drought indices that are calculated directly based on meteorological data, such as rainfall, In the absence of such data, will not be useful in monitoring drought. The remote sensing techniques can be considered a useful tool in monitoring drought. In this research, using MODIS sensor data, Normalized Difference Vegetation Index Change during the years 2000 to 2008 were reviewed. In addition to vegetation, NDVI index can also be effective for drought monitoring, especially for dry farming.Considering this indicator, the vegetation cover was classified into 4 groups and areas were calculated for each class. Finally, SPI and NDVI were compared. The result of calculation of SPI shows severe droughts in 2008 and moderate drought in 2000 and 2008, respectively. NDVI index in the three years indicated that the poor vegetation cover is significantly increased. High level Pearson correlations (.704) observed between SPI and NDVI in significant level of 0.01. However, the results of the effect of precipitation on NDVI index showed, there is no simultaneous occurrence of meteorological and agriculture droughts for all year. For 2006, despite the fact that precipitation was higher than average rainfall, but in this year, agricultural drought (reducing the value of the index (NDVI) occurred. Conversely, in 2002 and 2004, which precipitation less than 2006, but dry farming and pasture conditions were better than in 2006. And also in 2003 by a margin of 2 mm in precipitation than 2002, NDVI index value dropped too much. The results emphasize on the definition of the index that show all of this issue.

Snow is one of the major sources of water in most parts of the world. Hydrology and climate studies determine that the snow cover surface area to be one of the important parameters of snow. One of the tools that has lots of uses in the watershed snow cover survey and hydrological properties is remote monitoring by satellites images. MODIS imageries compared with other images like NOAA has better spatial resolution and more bands and is better for this surveying. Therefore in our study for mapping of snow cover we used MODIS images and NDSI indicators. In the snow mapping algorithm, at the first stage the NDSI index snow was isolated but for discrimination between snow and other wet lands we used the thresholds in 2, 4 and 6 bands. The results showed that the NDSI index in conjunction with the thresholds has appropriate effects for this purpose. In this research, the average error of snow cover maps including the error NDSI index was less than 20 percent.

In this research, an investigation on the changes of two major climatic parameters i. e., temperature and precipitation is done in the Mazandaran Province and west of Golestan Province with emphasi s on part of coastal line of Caspian Sea and its comparison with changes of these two parameters in scales of northern hemisphere and global. For this purpose, the time series of annual precipitation and mean, maximum and minimum temperature in three the Gorgan, Babolsar and Ramsar sites, were analyzed during statistical period of 1956-2005 and in five decades and also nine other sites with various statistical periods from 19 years to 36 years. In this research, used from non-parametric tests of Mann-Kendall and sen ׳ s estimator of slope to detect trend qualify and quantity respectively. Results indicates that Changes in mean of five decades than long mean and also relationship of temperature and precipitation changes in three sites of Gorgan, Babolsar and Ramsar is observed that with decrease in temperature, is seen a decrease in precipitation and with increase of temperature, an increase in precipitation is observed. This concept, only in five the 10-year periods is seen as separate and trend in these two parameters during the 50-year period is to the other form and in three stations is different; so that average temperature is increased and precipitation is decreased in Ramsar site and regional average, and in two Babolsar and Gorgan sites is observed increase and decrease of these two parameters respectively. Also in two global and northern hemisphere scales, is observed increase of average temperature and decrease of precipitation that take place opposite of each other and is similar to changes in these two parameters in Ramsar site and regional average. Also investigation of minimum and maximum temperature in these three stations, in general, showed stronger increase in minimum temperature than maximum temperature, and it can be in relation to increase in greenhouse gases that has more impact on increase of minimum temperature. Generally, increase in temperature is observed in all of case study sites with the exception of the Gorgan site and also precipitation in different sites has various changes that this condition can be result of increase in greenhouse gases in local, regional and global scal e s and also distance from voluminous reservoir of Caspian Sea.

Because of urban rapid growth of Iran, some problems such as propagation of environmental pollutions, urban inundation and flood hazards due to lack of appropriate drainage systems and irregularity of conduits & streams are the major difficulties in urban watersheds. Because of hydrological & hydraulic processes complexities in urban area, using of computer models would be effective. In this study, EPA-SWMM model applied for quantitative simulation of flash flood in some parts of Babolsar urban watershed.12 hour's simulation was done for 2 hours design storm with 2, 5 and 10 years return periods. Quantities simulation results shows that among the 259 junctions in the drainage network of study area, 32, 57 and 60 junctions for 2, 5 and 10 years return periods were inundated respectively. Peak discharges for 10 junctions of study area drainage network, estimated by rational method compared with simulated ones shows good linear correlation. Field investigations, Elevation maps of conduits and conducted simulation implies that the main reasons of inundation are small cross section area of conduits and also low bed slope & invert slope in some places. Conformity of flooded junction's simulation results due to rainfall with historical events in study area verifies the model simulations.

Nowadays, the accurate estimation of rivers suspended sediment load (SSL), from various aspects, such as water resources engineering, environmental issues, water quality and so on is important. In this regard, because of various roles of fixed and dynamic variables of watersheds, the watershed hydrological models have not showen a proper efficiency in statimation of SSL. Also, the most SSL studies are based on only flow discharge variable whereas the results of the present study have proved that the efficiency of these modeles is very poor. On the other hands, the parameters such as rainfall type, year seasons and flow hydrograph shape have important role in watershed sediment yield that were ignored in the most SSL simulations. In the present study, multi layers perceptron neural network and hydro-meteorological data (daily flow discharge, suspended sediment concentration, daily rainfall and temperature) of Karaj dam watershed in a 30-year period (1981 to 2011) were used to estimate daily suspended sediment concentration of Sierra station. Due to the role of seasonal changes and flow conditions in sediment yield and sediment transport of the watershed, based on rainfall regime, hydrograph condition and runoff type, the data used in this study were first seperated into 5 groups and then for each group, a separate model was designed. In order to increase the generalization ability of the neural network models, self-organizing map (SOM) and Silhouette coefficient were used for data clustering and determination of the optimal number of clusters respectively. The research results showed that the use of daily precipitation and temperature variables along with flow discharge and data separating based on watershed time and hydro climatic conditions has had an important role in increasing the accurate estimation of the river sediment. In this regard, among the models, the maximum calculated error is when only a single model is used for all year seasons. The research results and its used structure can be used as a pattern to estimate and to forecast many environmental variables of watersheds.

Soil erosion is a serious environmental problem in Vazroud watershed, which is located in the centre of the Mazandaran Province, Iran. Unfortunately, Vazroud watershed like most Iran watersheds don’t have recorded data and erosion and sedimentation gages to research, monitor and model soil erosion at large watershed. In order to assess the soil erosion risk, soil erosion modeling at the watershed scale are urgently needed to be undertaken. This study integrated the Revised Universal Soil Loss Equation (RUSLE) with a Geographic Information System (GIS) to estimate soil loss and identify the risk erosion areas in the Vazroud watershed. Multi-source (map-, space- and ground-based) datasets were used to obtain factors of RUSLE, and an integrated analysis was carried out in raster format of GIS and it was classified into five categories ranging from minimal risk to extreme erosion risk. Extensive field observations verify soil erosion risk map and total accuracy (90%) obtained. The soil erosion map was linked to land use, elevation and slope maps to explore the relationship between soil erosion and environmental factors and identify the areas of soil erosion risk. The slopes between 25 to 45 degree, the altitudes between 1180 to 2180 from sea level and bare lands have the high and extreme erosion risk in this study area. The results allow decision makers to implement management strategies to prioritization area and soil erosion reduction in Vazroud watershed. The integrated approach presented is relatively easy, fast, and straightforward, showing good potential for successful application in other areas.

Climatic parameters in time and space scales of change are for many reasons of Changes and how they should be based on observations using a statistical method to be determined. Analysis of the most widely used statistical methods that assess potential climate change on hydrological time series, such series of precipitation, temperature and flow rate used. This study of 11 synoptic,rain gage and climatology stations with 30 years during the years 1979 to 2009 period is Charmahal o Bakhtiari province.Mann-Kendall non-parametric and  sen estimate tests were used for the purpose of the study.The results showed that 11 stations were the only station in sepid dasht 95 and 99 percent had significant levels decline and changes in the slope is negative and other gage stations does not have significant trends. The results of this study can be in the long-term planning for water resources management, irrigation scheduling and prediction of future droughts in the province can be used