JOURNAL OF WATERSHED MANAGEMENT RESEARCH
Year:2018 | Volume:9 | Issue:17|Papers Count:26

IIntegrated watershed management is known as a new pattern of planning which emphasizes importance of the sustainable development and management of on watershed: water and soil. Therefore, the goals of watershed management will be fulfilled when an integrated management is employed on watershed’ s resources. In this study, Ghotorchay watershed is located in West Azarbaijan province, Iran was prioritize according to the health rate. The study area with 6800 ha the study watershed is divided into 11 sub-watershed. Toward this purpose, indices are defined that play main role in the health rate of watershed and show the importance of watershed components. Communications and interactions of each sub-watersheds constituent parts are considered to evaluate the indices. The sub-watershed are divided into five categories: biological condition (species richness), continuity (the number of structure per unit length of river), geomorphology (sensitivity of soil to erosion and climate), hydrology (perennial vegetation and impervious surfaces), and water quality (point and non-point sources). Eventually, the sub-basins were prioritized in terms of each index and the final map was obtained by combining all the calculate criteria. The results show that the health rate of watershed is medium (50-60%), sub-basin 11 has the highest watershed health with 60. 39 score rather than other sub-watershed and sub-watershed 6 has the lowest watershed health with 50. 71 score with respect to other sub-watersheds. The cause of reduction of health was assessed in each sub-watershed and solutions to improve health and prevent the decline was proposed that these results can prioritize actions to improve and strengthen watershed services should be considered.

Construction of Reservoir dams on the river, in addition to change and decrease the river’ s regime in downstream, cause environmental problems for ecosystems. This issue can be more severe by dumping pollution into rivers. Therefore, estimating the minimum environmental flow for river systems and other aquatic ecosystems is necessary to keep environment and water resources. In this study, the environmental flow of Dez River was determined using optimization of Dez outlet on upstream. For the purpose, a safe range of environmental flow, with 10 to 100 m3/s, was firstly defined. Then, simulation of river water quality for mentioned ranged was done by QUAL-2K model. Next, by using Nash's theory of conflict resolution, the optimization of the dam release, under three scenarios of relative weights for quantitative and qualitative aims, was determined that 66, 57, and 74 m3/s were obtained respectively, the average concentration were 2. 926, 3. 237, and 2. 727 respectively for each scenario. Each of this value can provide different percentages of quantitative and qualitative needs, so the prioritization of these aims was given decision makers.

Kashafrud Watershed Area is the part of the Great Plains Gharehghom in the northeastern province of Khorasan Razavi with area of 8996 square kilometers and considered the main drain Mashhad plain. to determine flooding potential of Kashafrud watershed used of modified SCS Method, the GIS system according to classification of map watershed and Tamab grade 4 in the digital elevation model, mapping the distribution of precipitation, precipitation losses and land use. Meteorological data, including precipitation statistics and rainstorms (28 stations) related to the period received of the relevant organizations and reviewed. After calibration data based on a common time base for 25 years (1989-1988 to2013-2012) and remove of suspicious data, in some cases rebuild the lengthening period. Layers of information is used such as maps: weather stations location, topography, land use, soil, vegetation, Political divisions of province and divisions watershed of Tamab. receiving DEM and making any necessary modifications basin boundary and physiographic characteristics calculated such as area, perimeter, height, slope, time of concentration. value of CN calculated by using the land use map and soil hydrology groups performed. Analysis Storm determined by using the software SMADA and standard distribution function (Pearson type 3) and value of of rainfall and storm return periods of 2 to 100 years. After calculation of weighted average height of the runoff in each subwatershed (sub 86), to determine the flood zones watershed, estimates maximum flooding (Qmax) caused by rainfall effective and drawn flooding potential map of watershed. Of the total area of watershed is, 68. 25% of the normal flooding potential, 25. 5% of of critical and is 6. 25%. supercritical flooding potential. Cities Chenaran and Mashhad are flooding potential than other cities. From a total of 658 villages and population center recognized in watershed, 78% of the villages due to their placement in plain areas and low-slope are in the zone of potential flooding normal, 17% of the villages in the area with the potential flooding of critical and 5% of the villages due to the inclusion in the Highlands and steep with the potential flooding zone supercritical.

For modeling, the concept of the system and the system boundary is necessary. The system is defined as a group of objects that in order to fulfill a specific purpose in the framework relationship or interdependence of regularly are interconnected. Systems rainfall-runoff from rainfall in the basin is started and after applying the types of losses (evaporation, infiltration, etc) it will become runoff. In the study of the HEC-HMS model for show the effectiveness of the sub-basin in runoff of the watershed is used; so SCS curve number method for losses method and SCS unit hydrograph method for transmission method were used. In beginning distribution basin model with three sub-basin then as an lumped basin model was run. The results show that the accuracy of the model in the watershed by taking sub-basin is more than lumped basin model.

By increasing the intensity of rainfall, runoff, which is considered as a very important factor in soil erosion process, occurs. Climate, geometrical characteristics of watershed, geological formations, soil, vegetation and land use are among factors affecting runoff generation. Although in plots under rainfall simulation, the experiment time is more limited and the effect of rainfall duration on the results is more tangible, this effect has been less considered. The present study was therefore conducted to evaluate the effect of rainfall duration in 6 levels of 5, 10, 15, 20, 25 and 30 minutes with 3 replications under constant rainfall intensity of 40 millimeter per hour on runoff parameters including commencement time, volume, coefficient and end time and sediment concentration. The field plots under rainfall simulation located in an eastern highland slope of Kojour Watershed were selected to achieve the study purposes. The Results indicated that the runoff parameters were significantly increased (p≥ 0. 05) with increasing rainfall duration while the rate of increase was not the same in different rainfall duration levels. In other words, under the present study conditions, the turning point of hydrological response to rainfall duration was occurred between 25-30 minutes, where the gradient of runoff parameters with rainfall duration was considerably increased. The results also showed that the sediment concentration decreased with increasing rainfall duration.

Accurate simulation runoff process can have a significant role in water resources management and related issues. The inherent complexity of this process makes difficult the use of physical and numerical models. In recent years, application of intelligent models is increased a powerful tool in hydrological modeling. The aim of this study was the application of the Gamma test to select the optimal combination of input variables for runoff modeling in Sofi Chay. Streamflow modeling was performed based on the optimum number of the selected variables using the artificial neural network (ANN) and Support vector machine (SVM) methods. Gamma test results showed that monthly runoff with six antecedent runoff values provide better results to predict. Runoff simulation using support vector machines and artificial neural network models also showed that the best input structure will be delayed until six to predict of next month runoff. Among to models with the same input structure, support vector machine have relatively high efficiency compared to artificial neural network.

Floods are one of the most common natural disasters which causing financial and life losses, yearly. Therefore, to reduce the harmful effects of flood occurrence, it is necessary to prepare vulnerability maps for flood management. The aim of the present study is flood inundation mapping of Jahrom Township, Fars Province using multi-criteria decision making techniques such as AHP and TOPSIS and a statistical model namely weights-of-evidence (WOE) and comparison of their performance. A total of 53 flooding locations were identified in the study area, 35 locations were randomly assigned for modelling process and the remaining 16 locations were used for validation aims. Nine factors that affect the occurrence of flooding were considered and their maps were prepared in ArcGIS software. These factors are slope degree, plan curvature, elevation, topographic wetness index (TWI), stream power index (SPI), distance from river, land use, rainfall, and lithology. After the flood susceptibility mapping using the mentioned methods, results were evaluated using recivier operating characteristic (ROC) curve. The area under the curve (AUC) of applied models shows the accuracy of 68, 70, and 86 percent for AHP, TOPSIS, and weight of evidence statistical models, respectively. Also, results showed that statistical models have a better accuracy in comparision with MCDM models and expert approaches. The results of present study could be useful to managers, researchers, and designers for better managing the flood affected areas and to reduce its damage.

Flood as a rapid and destructive event causes great human and economic losses in Iran and around the world, annually. This study aimed to assess the temporal trend and spatial changes of flood coefficient of Ardabil Province rivers using daily discharge of 22 hydrometric stations over a 22-year (1991 to 2011) of recorded data. The flood coefficient amount was calculated after subtracting the defined base flow resulted from the local minima technique. The non-parametric Mann-Kendall test was used to detect the temporal tend in the time series values. The recorded data length were divided into 5-year periods and the variations of changes of flow rate in different periods were analyzed. The significant differences were determined by using the Kruskal-Wallis statistical test. The results showed that changes of flood coefficient was significant (p<0. 05) between different periods. The spatial changes of flood coefficient variation coefficient showed a similar spatial pattern in different studied periods and the highest variability were defined at North-East and West parts of the study area. The highest rate of flood coefficient was observed in Akbardavood station with the value of 0. 8 in the fourth sub-period. According to the results of trend analysis, there is an increasing significant temporal trend in 6 stations, and one station had decreasing trend, while other stations had increasing trend with no statistical significance. The increasing trend of flood coefficient can be related to rainfall variations and land use change along with intensified use of extensive rangelands areas which increases the potential runoff and surface flow resulting increase in the flood coefficient in the studied statistics.

Rain gauge stations that measure fine scale rainfall are mainly limited in number or in the length of the recorded data. Therefore, temporal disaggregation models have been considered because of their ability in generating fine scale data from coarse scale measurements of rainfall. In this study, microcanonical cascade model, which is based on the scaling properties of rainfall and constant volume of rainfall was used for the disaggregation purposes of rainfall. To this end, a software package was primarily developed based on the existing theory and then applied to rainfall data from two weather stations located in the Zanjan Province. In order to evaluate the performance of the microcanonical cascade model, comparisons were conducted between the observations and model results using some statistics including percentage of zero-values, volume of individual values, duration of events, volume of events and length of dry periods between events of rainfall. It was concluded that the use of microcanonical cascade model for disaggregation of daily rainfall to 12, 6, 3 and 1. 5-hour rainfall will bring favorable results.

Rainfall variability and its impact on water resources are important climatic issues. Intra-annual variations in rainfall are characterized as precipitation concentration index (PCI). Another feature that directly correlates with the concentration of precipitation is the rain erosivity (Modified Fournier Index MFI). The aim of this study is to investigate the PCI and MFI indices and map their spatial variations. The Modified Fournier and precipitation Concentration indices were calculated using rainfall data from 55 meteorological stations located in Khuzestan province. To produce the spatial variations map, point information is converted to regional using geostatistical and deterministic methods. The results indicated that the ordinary and simple Kriging with Gaussian type have highest accuracy for interpolation of the PCI and MFI indices, respectively. According to the spatial variation map of the PCI, the highest values of that index are seen in the southern region and the lowest values are in the north and northeast of the Khuzestan province. The PCI values ranged between 20 and 31 indicating severe seasonality. The MFI values vary from 49 to 224 in which the highest values are for the northeast region of the province and the lowest ones are for the south and southwest zones. Generally Rainfall limited in a certain months. alues are for the northeast region of the province and the lowest ones are for the south and southwest zones. Generally Rainfall limited in a certain months.

In this study, the predictive performance of three Artificial Neural Networks (ANNs), i. e. Co-Active NeuroFuzzy Inference System (CANFIS), Multi-Layer Perceptron (MLP) and MLP integrated with Genetic Algorithm (GA) in the Zoshk-Abardeh watershed were compared. In this study, three scenarios were considered and simulated in each model. In order to simulate the scenario S1 water flow were fed into the network as input. Daily water discharge and rainfall depth were considered as the input for the scenario S2. The scenario S3 was simulated based on the water discharge, daily rainfall and temperature as the inputs. In all scenarios daily sediment load was considered as the network output. Results showed that the optimum architecture for the S3_CANFIS (as the best network) was based on the Bell membership function, hyperbolic tangent transfer function and the Levenberg-Marquardt training algorithm. The S3_CANFIS with the lower MSE and NMSE acted better as compared with other scenarios during the testing process. This scenario based on the NSE equal to 0. 743 and the AM equal to 0. 806 showed better performance, as well. The results also suggest that the S2_MLP with 5 neurons in two hidden layers, sigmoid transfer function and the momentum learning algorithm with NSE and AM equal to 0. 604 and 0. 626, respectively acted better as compared with other MLP scenarios. Since the MLP network compared with CANFIS showed weaker performance in sediment yield simulation, the GA was integrated with MLP to determine the optimal network architecture parameters for the S2_MLP. Results showed that GA-MLP with NSE and AM equal to 0. 658 and 0. 655, respectively led to a higher capability for sediment load simulation in comparison with MLP network. Totally, the S3_CANFIS according to the criteria MB equal to-0. 043, NSE equal to 0. 743 and AM equal to 0. 806 showed better performances in predicting sediment yield than the other networks in the studied watershed. However, both networks did not show a satisfactory power in sediment load simulation which could be arisen from the lack of data (especially extreme data) in the training series and also the existence of systematic error in observed records.

The landslides impose serious damages to the economy, environment and human throughout the world. Identification of areas susceptible to landslides is necessary to avoid risks. In This research for Landslide hazard zonation in sarkhoon karoon watershed have been used Shannon’ s Entropy Index and Information Value Methods. For this purpose, at first, landslide locations were identified using satellite images and field surveys and then landslide inventory map was created for study area. In the next step, 10 Effective Factors in Landslide occurrence include altitude, slope, aspect, distance from road, distance from fault, distance from river, lithology, land use, stream power index, topography wetness index, Plane Curvature and Profile Curvature were identified and mentioned maps will be digitized in GIS. In order to determine the weight of factors used Shannon’ s Entropy Index and to determine the weight of classes used Information Value. The final Zonation map in the five classes include potential risk of very low, low, moderate, high and very high were prepared. The ROC (Receiver operating characteristic) curves and area under the curves (AUC) for landslide susceptibility map were constructed and the areas under curves were assessed for validation purpose and its value showed that the hybrid model has a higher efficiency (0. 781) for landslide hazard zonation. Results showed that land use and distance to road factors have the greatest impact on landslides. According to the results of landslide maps 14. 45% (11220. 4 ha) of the area are ranked as very dangerous areas and 6. 11% (4744. 1 ha) as dangerous areas. The results of this research can help planners to choose favorable locations for development schemes, such as infrastructural, buildings, road constructions, and environmental protection.

Slope instability and mass movement of soil are the most important concerns of road construction scientists and experts as well as environmentalists. Soil is the main material of forest road construction and forms the road bed. In this research in order to avoid time and cost waste in mechanic soil laboratory, the region was divided into same units based on landform in GIS software. 10 soil samples were taken through systematic randomize sampling method from 20 land units. Totally, 200 soil samples were taken and the soil moisture, bulk density and texture were analyzed. New homogenous units were produced using the classification of soil experiments results. Therefore, in optimizing process of sample numbers the sampling intensity dramatically decreased to 100 samples without changing accuracy and reliability. Atterberg and shearing resistance tests were done on these samples. Results showed that the percentage of Fine-Grained Soil at both depth (10-30 and 70-90 cm) of instable units was more than that of stable units. Liquid index in instable and stable units were 0. 38 and 0. 09, respectively. Plastic index in instable and stable unites was recorded as 45. 88 and 19. 07. Moreover, the mean of shear resistance of soil in instable units was lower than that of stable units. Drainage services are proposed for instable units with plastic properties.

Mudflow erosion is a pervasive problem with adverse consequences for natural ecosystems in most parts of the world. The main factors creating Mudflow erosion are heavy rains, snow and ice melts and flooding rivers. In this study, the effects of slope position and land use type on Mudflow erosion at hill slopes with three different land uses were investigated. For this purpose, three hill slopes with the same conditions were selected in the land uses. Thereafter, three profiles were drilled at the shoulder (the highest erosion), backslope (average erosion) and footslope (lowest erosion), respectively. After studying and determining the soil layers in each profile, soil samples were obtained from two layers of surface and subsurface. Some soil physical, mechanical and chemical properties were then determined in each sample with three replicates. The results showed that the greatest LL value in the forest land use was observed in the middle slope which was 28. 64 and 25. 90 in the two investigated layers, respectively. However, in the pasture, the highest LL values were 37. 07 and 33. 94, respectively. Furthermore, the land use type had a significant relationship (P<0. 01) with OM, CCE, clay, SM, LL, PL and PI. The sand, soil activity index, cation exchange capacity (CEC) and the ratio OM/Clay had significant (P<0. 05) relationships with land use type while the silt and CEC/Clay parameters had no significant relationship. Forest with an average OM of 1. 149 percent had the greatest organic matter content and the degraded pasture had the lowest value (0. 47 %). Also the degraded pasture with an average clay content of 16. 6 % and silt content of 47. 37 % had the highest clay and silt values. The soil activity index in this land use type was 0. 36. Liquid and plastic limits in the degraded pasture were higher than the pasture, and the pasture was greater than the forest. The results of this study reveal that the degraded land uses have more potential for the occurrence of this type of erosion due to the high fine materials and saturation moisture percent and also poor soil surface cover.

Every year, due to population growth and economy development, land uses and land covers are changing. The various types of land uses have significant roles on components of water balance of a watershed. The simulation modeling has the capability to predict floods, to evaluate land use impacts on floods, and to make decision in watershed management. In this research, the effects of land use change scenarios such as current state, deforestation, 100-percent growth of urbanization and the combination of two scenarios (i. e. deforestation+ urbanization) have been evaluated on the water balance using the WetSpa model in the Ziarat watershed, which covers an area of 95. 15 km2 and located in Golestan province. In order to execute the WetSpa model, the hourly hydro meteorological data including rainfall, evapotranspiration, temperature, and discharge are used as inputs for a four-year period (from 2007 to 2011). The result of the simulation shows a good agreement between the simulated hydrograph and the observed one. Then, the scenarios of deforestation, urbanization development and the combined scenario of deforestation with urbanization have been designed in GIS environment, and the simulation was performed using the calibrated model. The finding showed there were increases in surface runoff and subsurface flow, groundwater and total flow rates; the maximum change was for runoff rate that increased 5. 2 in first scenario to 18 mm in fourth scenario. The decrease of land surface roughness and vegetation canopy lead to decrease in evapotranspiration and leaf interception in the study area.

Agricultural hillslopes with susceptible loess enters a large amount of runoff and sediment into the Gorgan city annually, due to the inappropriate drainage system which cause a lot of financial losses city. The purpose of this study was to investigate the effect of different vegetation scenarios on the runoff and sediment discharge from three hillslopes of catchment of 5. 9 hectares. The runoff and sediment of the catchment were simulated for one year using WEPP model. In addition, eight vegetation scenarios include present condition, extremum potential vegetation scenario, existence and lack annual and permanent vegetation were simulated and compared in pairs. The total runoff volume and sediment yield for the current condition of the catchment was estimated at 1945 cubic meters per year and 1. 5 tha-1, respectively The scenarios comparison indicated that the runoff and specific sediment rates were increased respectively from 1487 m3 meters per year and 0. 4 tha-1, in the maximum potential vegetation scenario (more than 80%), to 5032 cubic meters per year and 64. 5 tha-1 in the minimum vegetation scenario (fallow whit tillage). The difference of specific sediment rate between two scenarios of permanent vegetation cover and agriculture cover is equal to 8. 1 tha-1, and this amount was calculated of 10. 2 tha-1 for two scenarios of the lands under cultivation and fallow condition.

The most important factors affecting soil erosion and runoff include climate, soil erodibility, topography, vegetation cover and land management. In this article, an assessment of topography, slope and climate effects on the runoff production within marly lands in Zanjan province by using an artificial rain simulator. In this regard, by overlying slope, climate, and marly units of geological formation maps, by incorporating a rain simulator and an overall of 220 plots were tested. Data, collected from field operations, were analyzed on the basis of Randomized Complete Block Design with Factorial Treatment Structure. The upper red marl units (Mu) has the highest volume of runoff With volume of more than 20 liters per square meter marl and marl units Pliocene (PL) The minimum With volume of 1 liter one liter per square meter respectively. The Pliocene marl units (PL) has the highest infiltration rate of 12. 5 cm and lower red marl (OL) had the lowest infiltration rare is about 2 cm. The F-test results of Marnie units on volume and run-off coefficient were statistically significant, while the effect is not significant for the slope and climate on these two features. But in cases of double and triple combinations of these three variables in all cases have a significant effect on runoff generation and runoff coefficient. Statistical data analysis shows the significant effects of the Marl units, Slope and climate on the volume and run-off coefficient (p<0. 05). Marly unit can be classified in to four groups, based on the Volume and run-off coefficient, so that Marls of Pliocene (PL), Qom (OM) and lower red (OL) are in a separate class and upper-red (Mu), and Eocen (EM) Marl units are in a unique group. Accordingly, it can be said that the four groups differed in volume and run-off coefficient are significantly different from each other. The results of the slope and climate effects on these two traits showed significant effects on volume and run-off coefficient of the marl units.

Designed and undersigned fires in rangelands affect vegetation and soil, and then are necessary to give enough knowledge about them. Infiltration is one characteristic that have predict had affected by fire but had not studied enough yet. So spot fire have been seen in Artemisia aucheri type in Charat sub watershed at Mazandaran province, in this research were investigated primary, final infiltration and infiltration rate in different intensities and seasons. For this prepuces first were established tree 100m transects randomly and then tree 2m2 plots on each transect. Fire treatments in plots following without fire, light surface fire as much as direct burning and without flammable material of plants and surface litter (without ash product) and intense surface fire as much as direct burning of flammable material of plants and surface litter (with ash product). In the next stage was measured infiltration in different seasons using double rings. Data analysis of primary, final infiltration and infiltration rate in different intensities and seasons was carried out using two ways ANOVA and compare means test in SPSS software ver. 20. Results were shown that primary, final infiltration and infiltration rate are more in summer than the other seasons and are 5. 224, 15. 534 and 7. 756 cm/hr respectively. Infiltration in area without fire had no significant different by area with light fire but amount of final infiltration in area with intense fire was fewer than other seasons as was reduced from 3. 946 to 2. 447 cm/hr.

Babolroud watershed and Mazandaran province of such as are that in recent years, different extreme events have been happened. On this basis, emphasize necessity to investigate further on impact of climate change on watershed runoff. This work is done by climate change and rainfall-runoff models that able to simulate and calculate of climate changes impact on hydrologic components Including precipitation, temperature, evapotranspiration and runoff. In this study, using this method, the data model HadCm3 general circulation of the atmosphere with the use of LARS WG model according to A2 (pessimist), B1(optimist) two scenarios for the time periods 2046-2065 and 2080-2099 be downscaled. Then predicted variables were introduced to SIMHYD rainfall-runoff model. The simulated daily runoff in the period 1982-2011, were selected the best period of calibration and verification with regard to the duration and optimizing statistical parameters and model sensitivity analysis process, in order to minimize the simulation error. The results showed a reasonable match of the runoff changes pattern between the observed and simulated. So that relatively high values of coefficients of determination (R2=0. 73) and Nash-Sutcliffe (0. 53) during calibration, validation, indicated the model efficiency to simulating common and minimal flow. The results, showed some changes in the average annual rate SIMHYD, +23 to +58 percent that the highest increase rate in October and November and the largest decline in July and August in the future years are. The situation of low rainfall months will be shift to more drought and rainy months toward the flooding.

The impacts of climate Change, more than being influenced by the change in precipitation amount, is affected by the changes imposed by this phenomenon on rainfall regime (intensity and frequency); it means that climate change can cause extensive droughts/floods due to impact on temporal and spatial rainfall distribution, and hence, conducting some studies on return period of extreme rainfalls seems to be necessary. Current paper investigates and analyzes the effect of climate change on extreme regime in WFD catchment at three time horizons (2036, 2060, and 2090) under A1B, A2, and B1 emission scenarios. Investigations (performed by the authors during previous researches) show that the most accurate which is capable of simulating the trend of precipitation variations in the studies catchment, would be MRI-CGCM3 Downscaling was performed using Change Factor (CF) method. The results are representative of reduction in rainfall amount in future time periods, So that the predicted rainfall reduce between 4. 12 to 11. 69 percent compared to observed baseline precipitation. In addition the result of extreme rainfall analysis show that by moving towards the distant future, the amount of annual extreme rainfalls decrease for a specific return period. However intensity and return period of a specific extreme rainfall increases significantly and therefore, applying adaptive measures for urban flood prevention in the catchment appears to be necessary. Also the probability of extreme rainfall occurrence with a given value in distant future is greater than near future.

Flood control, artificial recharge of aquifers and attempt to optimize the utilization of the natural resources are some of the most important measures in the arid and semi arid zones that occurs by flood spreading projects. At the current study the impact of flood spreading on downstream qanat discharge at Myankooh area of Mehriz (Yazd province) was investigated. To gain this goal after collecting the discharge Statistics from 1997 to 2013, Standard Discharge Index (SDI) was calculated. The amount of flood water entering the aquifer areas and precipitation figures were used to calculate the Standardized Precipitation Index (SPI). The correlation between the SDI and SPI and flood volume was extracted. Also, the operators’ comments were collected by using the designed questionnaire. According to the results, the SDI increased at the same time as wet period and flood spreading time. But the share of each one on this invreasing wasn’ t clear. The correlation with SDI and SPI in different qanats was significant (1%) with 12, 6 and 3 months’ delay. Close to 28% operators assessed the project’ impact high, 43% very low and others moderate.

Incorrect management in Watersheds causes disorder of natural balance in groundwater resource and problems from water drawdown and consequences caused by non-optimum use of these water resources. In this research, in order to investigate the effect of construction of Alborz irrigation canals network on water table of Qaemshahr-Juibar Watershed and determination of maximum permissible water withdrawal from groundwater by water users associations of the region, in the condition of the performance Alborz network, the MODFLOW model was used. Besides the seepage water conveyance canals, recharge and discharge from the aquifer by Talar and Siahrood rivers, wells, return flow, rainfall and evaporation were all considered in the model. The model was run for a period time octobr 2004 to September 2004 in unsteady flow condition and was calibration with comparing observed and simulation water level. For model validation observations data for octobr 2008 to September 2008 was used the amount of RMSD was 0. 2. after examined the model, the aquifer was evaluated in three scenarios: 1) Aquifer condition before alborz irrigation and drainage network performance, 2) after performance and 3) withdrawal groundwater optimal conditions. The results showed, after Alborz design performance, Rise of water table it was 3 meter for one year. And the possibility of creasing withdrawal from ground water resources was 96 million cubic meter per year.

In recent years, with excessive extraction of groundwater resources, Hamedan-Bahar-plain’ s ground water level dropped severely. So it is important to apply appropriate management strategy for the optimal utilization of this resource. In the economic management of water resources, the main issue is a balance between supply and demand for water. In creating this balance, an important role is the economic value of water, like the prices of other inputs are. For this reason, to keep the sustainability of water resources in agriculture, water pricing method is used as an indirect method. The aim of this study was to estimate the economic value of water using spatial econometric approach. Because of the relationship between farms and groundwater resources, this study tried to answer the question of how this relationship affects the welfare of farmers. By accepting this issue, the use of spatial econometric approach is recommended. The correlation coefficient of the estimate showed that the use of spatial regression is superior to the classical regression model. The required data in this study were collected through field research and a questionnaire to farmers in 2016. The results show that the real price of water in potato production is 2040 rials per cubic meter. Therefore, controlling water consumption and balancing of supply and demand for water can be generated from the existing price gap for water pricing policies.

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.

Generally, Climatic extreme events, like the heavy rainfalls and sudden changes cause the greatest range of damages to water resources, agricultural and even human daily life. Therefore, correction and regular monitoring reduces their negative effects. Climatic signals represent changes of between temperature and pressure in ocean that they are one of the most influential parameters on climatic patterns. This study evaluates the effects of large – scale climate factors on rainfall extreme indices in Sistan-Baluchestan province as symbol of arid land in Iran that it has sever climatic oscillations. In order to at first step we use data of daily rainfall 6 synoptic stations at 1987-2014 period from meteorological organization and 19 Teleconnection indices from NCEP/NCAR. Then we calculated extreme indices. In continue correlation of extreme indices and teleconnection calculated. In next step we analyzed affecting teleconnection by regression model. The result of the correlation between teleconnection indices and extreme rainfall indices showed that TSI, TNI, AO, WP, WHWP, TNA, NINO1, EA, NINO4, PDO, PNAو NAO have correlation with rainfall extreme indices but this effects are different in station to another as in Khash station the most correlation occur with R50 and in Chabahar station occur with R10. So determined that teleconnection identify about 30 percent of changes.

The purpose of this study is analyzing the trend of drought characteristics in Hamedan Province In this regard, the corrected standardized precipitation index (SPImod) was calculated based on the monthly precipitation data from 11 synoptic and rain gauge stations during the period of 1985-2013. Drought characteristics, including severity, duration and interarrival time were defined and extracted based on the SPImod. The Sen’ s estimator was used to estimate the slopes of trend lines. The results show that in most of the stations, drought duration had a non-significant decreasing trend, while the drought severity in over half of the stations had a non-significant decreasing trend. The drought interarrival time witnessed a non-significant decreasing trend in all of the stations, except at the Varayeneh station, which experienced a significant increasing trend at 1%. The monthly rainfall experienced a non-significant increasing trend in most of the stations except Keyto which experienced a non-significant decreasing trend.