IRANIAN JOURNAL OF ECOHYDROLOGY
Year:2018 | Volume:5 | Issue:2 |Papers Count:28

Current research presents a systematical water allocation scheme for Bukan reservoir located in the northwest of Iran. In this scheme، the agricultural demands reduced by application of some fallow to satisfy other sector demands، when the system faced with a water scarcity. For this، the monthly water deficit ratio calculated for the historical period of 1995-2013. To determining water deficit thresholds in the reservoir it classified to five groups by k-means clustering method. For determining the optimized amount of fallow genetic algorithm used to optimize the operation of the reservoir for each crop year from 2007-2013. For assessment of the irrigation efficiency also consideration of the environmental demand effect to the fallow amount، six scenarios are applied. Results revealed that by increasing of irrigation efficiency it needs less fallow. Applying optimized fallow leads to deliver downstream demands at an acceptable level. So increasing irrigation efficiency should be as a priority of water managers.

The landscape metrics are used to quantify the spatial properties of landuse patches and classes as a useful tool in assessing effect of human activities on flooding processes. This study aims to evaluate the efficiency of HEC-HMS model in flood simulaion of Amoughin watershed and exploring the relationships of landscape metrics and the flood components. The HEC-HMS model was runned with SCS-CN (loss module)، SCS-Unit hydrograph (rainfall-runoff transformation) and Muskingum (routing). The model parameters were optimized using 6 events considering Nash-Sutcliffe objective function and three excluded events used during validation. The components of simulated hydrographs were defined by 25-year design rainfall. The landscape metrics were quantified using Fragstat and appropriate landscape metrics slected by PCA. The correlation and regression analysis were performed in R programming. The value of Nash-Sutcliffe criterion was 0. 63 in validation which proves the accuracy of model in flood simulation. The results showed a positive relationship between Qp، runoff volume and base time with total area (TA) and MESH metrics. Relationship of Qp with TA، patch density (PD) and slope were evaluated as positive (p-value<0. 01). While، the Qp had negative relationship with rangeland area. Also، the hydrograph Tp had a positive correlation with PD and river length.

Unit Hydrograph is a method for flood hydrograph simulation resulting n response to a unit of excess rainfall on the basin. The theory for unit hydrograph is based on two systematic principles called superposition and proportionality. So far several methods of unit hydrograph has been developed which show different responses and functionalities under local conditions of the basin. In this study we used a continuous hydrologic simulation from HEC-HMS model to compare the performance of three unit SMA algorithm and linear reservoir were selected as loss and base-flow functions of the basin، respectively. The flood hydrograph and its specifications including peak discharge and runoff volume were derived using three ways of Snyder، Clark and SCS methods. To compare the performance of models the Nash-Sutcliffe Efficiency was considered as as the objective function. Parameterization and validation of the hydrological parameters were done by changing parameters manually and a applying a trial-error method. Results showed for all three methods the percent of differences between the simulated and observed volumes for runoff was quite very close to each other. While in term of peak flows، the Clarke unit hydrograph method showed the best agreement between the simulated and observed peak discharges.

Kelale mountainous region is located in the east of the Golestan province. There are several karstic springs such as Zav، Aghsoo، Yal-cheshme in the region due to the existing karstic limestone and relatively high average precipitation value. The development of karstic formation in Kelale area and catchment area of four major springs has been investigated in this study based on geology، hydrogeologic and hydrochemical factors. In this area، springs are discharged from Lar، Tirgan، and Mozduran karstic formations and Sarcheshmeh shale formation. Different karst features such as closed depression، sinkhole، joint and fractures were observed in Lar formation during field investigation، then the Lar formation proposed as catchment area. The types of flow in all springs are conduit and diffuse flow. Zav and upper Yal-cheshme with three recession coefficient، are fed by a well-developed karstic aquifer; while the recession curve of Aghsoo and lower Yal-cheshme have one recession coefficient، indicating weaker karstic development in the basin. All the springs have the same origin and mainly have Ca-HCO3 water type. Cation exchange also affects the hydrochemical characteristic of the springs. All springs are super-saturated with calcite and dolomite but under-saturated with gypsum and halite.

The aim of study was set to evaluate components of the hydrological cycle in Tilabad Watershed during future periods as affected by the predicted land use change. For this purpose، using MSS (1986)، ETM+ (2000) and OLI (2015) Landsat satellite images a land use map was produced in seven categories. Then، two likely future land use maps were predicted based on Markov chain modeling and cellular Automata approach for the years 2025 and 2040. Simulation for 2000-2014 years and by using SWAT model and SUFI2 program was done. The results of maps assessment of the years 1986، 2000 and 2015 with the kappa index 0. 9553، 0. 8655 and 0. 9612 respectively، shows destruction trend overall. The match assessment between simulated and actual land use for 2015 showed a kappa coefficient 0. 7993. In the analysis of land use was determined with degradation of the region to runoff، sediment، the water، subcortical flow، and evapotranspiration increased and the amount of groundwater flow، backflow from the aquifer surface، deep aquifer recharge، and permeability and Hydraulic conductivity were reduced significantly. Also، the value of peak and medium was increased and base flow as reduced. Generally، the effects of changes in 2040 Compared to 2025 was more.

Due to the importance of climate change phenomenon، “ Urmia Lake Basin” ، as one of the most important basins in Iran from environmental، economic، social، etc.، aspects، was selected to study climate change and its effects on surface flow. In this study، the outputs of HadCM3 were downscaled by SDSM downscaling model، under A2 and B2 emission scenarios and then، the future stream flow data were simulated by the use of IHACRES model for the period of 2041-2070. The results showed that the amount of precipitation will decrease 0. 1 mm under the A2 scenario and will increase 0. 03 mm under the B2 scenario in future. Using HadCM3 model revealed that the mean temperature will increase 1. 2 and 1. 1 ° C under A2 and B2 scenarios، respectively. The results of stream flow simulation revealed that the surface flow will increase 24. 6 % under the A2 scenario and will decrease 4. 6 % under scenario B2 in future. Based on the climatic scenarios assessment، climate change will impact on water resources of the Basin and studying these effects by different methods will provide better results for decision-makers of the Basin.

Rainfall-runoff modeling is one of the key items that considered in hydrology to achieve flood characteristics. In this study، HEC-HMS model performance was evaluated using the SCS-CN، Green-Ampt and Initial and Constant infiltration methods in predicting runoff volume، peak flow and time to peak، in simulation of rainfall-runoff hydrograph at Gharasoo watershed، located in Kermanshah province. Eight rainfall– runoff events were simulated by HEC-HMS model and compared with the corresponding observations events. Results shown a well accuracy in predicting runoff volume (R2=0. 84، E=0. 81 and CRM=0. 06) was achieved using the SCS-CN method (after calibration). However، Peak flow was better estimated using the Initial and Constant method (R2=0. 96، E=0. 95 and CRM=0. 01). Furthermore، shape of the calibrated hydrographs were very similar to the observations hydrographs for both SCS-CN and Initial and Constant methods. However، adopting the Green-Ampt method، showed low reliability in total runoff volume and peak flow estimating. Model accuracy in estimates of modeled the time to floods peak، were evaluated by comparing observed and simulated values through the selected approaches، so that the results of time to floods peak showed the highest reliability in SCS-CN method (6. 36%).

Due to lack of data، using of rainfall-runoff models with high accuracy that do not need to large amounts of data is an important issue. The IHACRES model is a semi-conceptual rainfall-runoff model. This model does not need to large amounts of data and calculates effective rainfall. Then this model simulates the value of runoff. The case study of this research is the Navrood watershed in the Gilan province. For simulation of rainfall and runoff in this research، IHACRES model utilizes daily flow discharge data in the Kharjgil hydrometric station and daily precipitation and temperature data in the Khalian synoptic station. The Kharjgil hydrometric station locates at outlet of watershed and the Khalian synoptic station locates at center of watershed. The model uses from data of time period 1391 to 1394 for calibration and time period 1387 to 1389 for cross validation. Nash-Sutcliffe model efficiency coefficient (E)، mean of total error (BIAS) and average relative parameter error (ARPE) criteria are utilized evaluation of results of model. The value of E is 0. 55 and 0. 46 for calibration and cross validation respectively. These values show that results of this research are acceptable in comparison with previous researches.

Scouring and variations of bed topography in meandering river is one of the most interesting issues in river engineering. Vegetation is a significant feature of rivers. Various studies have shown that the presence of vegetation may have an important impact on flow field and river morphology. Due to the complex geometry and hydraulics of flow in natural rivers، physical or mathematical models are often useful to evaluate morphological variations. The purpose of the present study is to investigate the morphological changes in alluvial meandering rivers with compound cross section to gain insight into the physical processes involved. Hence، the bed topography in an alluvial meandering asymmetric compound channel is assessed with vegetated and non-vegetated floodplain conditions. Cylindrical rods of 10 mm diameter were used to simulate rigid vegetation. The rods were installed over the floodplain in two parallel patterns with one row and two rows of vegetation، respectively. The results showed that the point of maximum scour depth was located near the outer bank. Due to high flow velocity entering the bend، the scour depth at section entrance of the bend was greater than other sections. Also، the thalwege was moved away from the interface after planting the vegetation.

Drought is a consequence of fluctuations in climate conditions that their effect on human societies is more than another phenomenon. For drought investigation، monthly data of precipitation in 9 synoptic stations of Fars province during twenty years period (1995-2014) was used. After calculation of drought severity using run theory، suitable index among DI، PNPI، SIAP، RAI، SPI and BMDI indices was selected. Then time series of drought severity fitted on different distributions and after selection of best distribution for each station، drought severity with duration 2، 4، 6 and 8 months in return periods of 2، 3، 5، 10، 25 and 50 years calculated and related table was prepared. Also using cluster analysis studied stations divided into different groups. At least، drought severity zoning map in 2 decades plotted in GIS. Results showed that Standard precipitation index (SPI) as the best index could be a proper interpret of drought computing. Generally، in study area drought severity increase in the recent decade.

Irregular groundwater consumption and not replacing it has reduced groundwater level in many of aquifers at Iran. So determination of suitable areas for artificial recharge is very important as a solution to this problem. The goal of this study is determination of artificial recharge basins location by fuzzy logic and then optimal design of these basins. The ratio of income to expense was used to selection of the basins best design. So، five height scenarios were defined. All of scenarios were simulated by HEC-HMS model and their income was determined as infiltrated water volume. Also، the expense of scenarios was calculated based on materials used in building basins. The results showed that the suitable areas for artificial recharge plan implementation are 0. 86% very efficient and 4. 7% efficient by fuzzy logic method. Also the best scenario is 2. 5 m based on the benefit to cost ratio and 2m based on the benefits view.

Recently، copula functions have attracted great attention of hydrologists as a practical tool for multivariate frequency analysis of climatological phenomena. In this study، we focus on the joint frequency analysis of two dependent characteristics of rainfall، including depth (mm) and duration (hr) using copulas for 522 events recorded in Sangdeh rain gauge station located in Kasiliyan watershed. To join the marginal distributions and constructing the joint distribution، seven copulas including Clyton، Ali-Mikhail-Haq، Farlie-Gumbel-Morgenstern، Frank، Galambos، Gumbel-Hougaard and Placket were used and evaluated. By comparing the mentioned parametric copulas with an empirical copula، we found that the Placket is the the best fitted copula on the considered variables. Finally، the joint probabilities، joint return periods and conditional joint return periods were calculated and plotted. For example، joint probability values for two events with duration of 12 and 24 (hr) given rainfall depth that exceeds 15 (mm) were calculated as 0. 2663 and 0. 7693، respectively. Also، conditional return period was calculated equal to 9. 19 year for an event with depth of 30 (mm)، given rainfall duration that exceeds 24 (hr) and equal to 14. 94 year for an event with duration of 24 (hr)، given rainfall depth that exceeds 30 (mm).

Allocation of rivers environmental water right as missing link in sustainable water resources management in Iran is undeniable necessity to preserve existing ecosystems in its catchments and preventing the death of wetlands and lakes which have been feeding by the rivers. In this paper environmental Water right for Ghoturchay River، important sub basin watershed of Aras river، have been studied using 4 hydrological Methods (Tennant، Tessman، flow duration indicators، Smakhtin)، and 2 eco-hydrological methods (Flow Duration Curve Shifting (FDCs) and Desktop Reserve Model (DRM)). Among these methods، FDCs in ecological class C has been chosen as an appropriate method because it’ s had more adaptation to hydrological and ecological conditions of studied region than other methods and considering ecological limitations and its flexibility in wet and dry months. In order to maintain the Ghoturchay River at minimum acceptable environmental status (i. e. Class C of environmental management)، average annual flows of 6. 94 m3/s (48% natural flow of the River) are to flow in it. This study showed that، average annual flows of 6. 5 m3/s arrives at the Aras River، which is approximately equal to the environmental water rights.

The river is a dynamic phenomenon that is constantly changing. Estimating the resistance of sediment particles against erosion will identify stable and unstable points in different areas of the bed. Study area of this research was of Masiel Mouchan River in the Astaneh city. In this study, we investigated threshold of (transformation and deposition of bed sediments, in 4 cross sections. the critical shear stresses and the critical unit discharge calculated for four particle sizes D16, D50, D84 and D95 in all sections, and results shows, sediments in D16, D50, D84 and D95 diameter moves at bankfull discharge in sections 2 and 4, therefore sedimentary conditions of the river bed will change at bankfull discharge. At cross sections 1 and 3, particles with a diameter of D84, D95 will remain stable in bed, and other particles smaller than this size was unstable. Sediment particle are unstable in cross section of 2 and 4, because Slope of cross sections 2 and 4 are greater than 1 and 3 cross section. Finally, the results of both methods (critical shear stresses and the critical unit discharge) have high confection and confirms these methods are useful for stabilization studies in other rivers.

This research assessment ability of entropy theory and Gamma test for input variable of Artificial Network and Support Vector Machine as evaporation estimation for Rasht, Astara and Anzali in Guilan province. According the results, for Rasht synoptic, Astara and Anzali, Entropy Theory is determined that existence all variables are effective for modelling. Gamma test, for Rasht station two variables contain maximum and average humidity, for Anzali station three variables, contain minimum and average temperature and average humidity and for Astara station one variable contain wind speed eliminated form optimal composition. According to results two model’ s Artificial Neural Network and Support Vector Machine performance have been acceptable. For determination of single input data in Rasht station Entropy Theory method and in the Anzali station Gamma test method have had good performance. For Astara station both of them have had good performance. Generally, according to the results, it can be said that Entropy theory had the stronger performance than Gamma test. But at the look of managerial, because the a few input variable selection than the Entropy theory, the Gamma performance has been acceptable than Entropy theory.

Soil erosion is one of the most important issues that human is facing now. The purpose of this research is to estimate the soil erosion in Iran using the RUSLE model and use of geographic information systems (GIS) and remote sensing data (RS). In the present study, after collecting and gathering various information including the digital elevation model (DEM) layers, Statistics on weather stations and rain gauges, satellite images and soil characteristics were used as research tools and Soil erosion was estimated using the RUSLE model. The average annual values of P, K, C, LS and R factors are 0. 65, 0. 04 (t h MJ-1 mm-1), 0. 46, 3. 6 and 195 (MJ mm ha-1 y-1 h-1), respectively. The results of this study showed that the average annual soil erosion in Iran is about 24 tons per hectare per year. Also, the results of the study showed that about 4 billion tons from soil the country eroded and partial entered the system of water in the stream and the sea which reduces the quality, water pollution, reduces of soil fertility and reduces the amount of cultivated land and ultimately leads to soil degradation.

Study of the spatial variations of sediment and its influencing factors, is essential to control it. In this study, the spatial variations of production characteristics and sediment concentration in a seasonal stream located in an erosional pediment, studied. The location of plots at the 50 meters intervals selected and experiments done in 10 locations (with 3 replications). Then a rainfall with rainfall intensity of 1. 4 mm/min and duration of 10 minutes, created using rainfall simulator and in the vicinity of each plot, surface soil samples were taken. The statistical analysis performed then using the cokriging method, the spatial distribution of characteristics prepared. The results showed that for sediment concentration variable among 10 locations, was no significant difference, but for the sediment load variable it was significant. The results of fitting experimental models on semivariograms, showed that the best fitted model to the spatial pattern of sediment concentration was gaussian and for sediment load was exponential model, respectively. Also two mentioned variables had strong spatial patterns. The results of the validation of applied model showed that the point-cokriging method has low accuracy to estimate sediment concentration, but for estimation of sediment load, the method has higher accuracy.

Iran as a country with extreme consequences of climate Faced with severe water stress. It is predicted that by 2064 the state of the country's water scarcity and climate change will still be affected. The effort to modify these changes has helped the technology to begin a few years ago with the help of technology Started a few years ago. In this paper, with the help of the Expert Panel and the Delphi process, Effective Key factors the development of these technologies in Iran has been investigated. And by being determined driving forces, we can, the scenarios for developing these technologies are outlined in Iran. By identifying three drivers with the highest uncertainty, we arrived at four different scenarios. The factors that have the most impact and uncertainty about Iran's access to Haarp technology include: a) political relationships with the countries affected by the implementation of the plan (due to the military-security dimension), b) financial support by the government, and c) access to specialized knowledge Primary Based on this, four scenarios were obtained: 1-continuation of 2-Haarp 3-misery 4-alternative strategies.

Using mulch is one of the ways which has been used so far to reduce the amount of evaporation. Accordingly, in this research, mulch effectiveness has been investigated in increasing the direct recharge of groundwater due to increased rainwater percolation. For this purpose, eight rainstorms with different durations and depths were tested. The depth of percolation of these rainfalls in the soil of 4 lysimeters with similar condition and different mulches, including gravel mulch, sand mulch, mixed 50% sand and 50% gravel mulch were tested as well as in non-covered soils. During the two months of the experiment, 192 data were collected for each soil moisture and rainfall percolation depth. The results showed that the mean rainwater percolation depth by gravel mulch, sand mulch and mixed sand and gravel mulch was respectively 19. 52, 2. 45 and 16. 60 percent increased comparing to the soil without mulch. It was found that mulching can increases rainwater penetration as one of the main sources of groundwater recharge, by reducing the amount of rain water evaporation and therefore the results of this research can be used to aquifer restoration.

The main objective of this study was to determine the contribution of sub-basin sediment yield using geochemical and radionuclide tracers in Ashan drainage basin. In view of this, 30 sediment samples were collected from 5 sub basin outlets and radionuclide tracers including 210Pb, 228AC, 226Ra, 137Cs and 40K and geochemical traces including calcium, iron, potassium, magnesium, Mn, Na and organic carbon were measured. The optimum set of tracers was determined using Kruskal Wallis test and discriminant function analysis. The relative contribution of sub-basin sediment yield was determined by using Bayesian uncertainty un-mixing model based on the optimum set of tracers. The tracers including 226Ra, 137Cs and 40K, Mn and Ca were selected as optimum set of tracers with 80% correction of determination. The results showed that the sub basin of Heris (3) has the highest amount of sediment yield (70. 1 %). The most lithology of this sub basin is pyroclastic and clay stones and soil conservation plans in order to reduce sediment yield should be focused on this sub-basin.

This study was conducted in chegeni mountainous basin, with an area of 1836 Km2. It is sub-basin of Doab Kashkan, that located in the north of the Lorestan province So that Landsat 7 Satellite ETM+ imagery sensor, selected for studies and correction of missing lines was conducted and albedo Surface amount, calculated by using Sebal algorithms. Since the except snow, two phenomena yellow and white sand and water have greater than 0. 3 albedo, then the snow cover map were provided for α > 0. 3, α > 0. 35, α > 0. 4, α > 0. 45, α > 0. 5 and α > 0. 55 albedos. To extract snow cover with sufficient precision, with this assuming, that snow cover is unknown, unmonitored classification was conducted for the albedo, then with applying of monitored classification on primary corrected image. The snow cover amount, was estimated, and kappa coefficient selected for evaluate the results of monitored classification and unmonitored classification for the mentioned albedo. The results showed that kappa coefficient for α > 0. 45 albedo, has highest value 0. 85. So α > 0. 45 albedo can extract snow cover to an acceptable level for us.

In this research, Sandia method, which is a statistical method, produces climatic sample data as a climatic file of real measured data for a period of ten years (2015 to 2005) for the synoptic meteorological station at Kermanshah Airport. Is. Then for validation another climatic file was created and compared with the literature software for Kermanshah. The results were compared with the average real data of the three main parameters of relative humidity and relative humidity, and the wind direction was compared and the climatic file was validated. The results show that the Sandia method is better compatible with the actual data of the synoptic meteorological station at Kermanshah Airport. Also, the analysis of the analysis of the temperature range (psychometric) analysis of the city of Kermanshah, the output of the software of Climate Consultant, which is depicted using the Sandia prepared climatic file, shows that in more than 17% of the year, the thermal comfort conditions in the city Kermanshah has been shown to indicate an increase in its range from previous studies, which generally indicates the warming of the city's climate.

The northern coast of the Persian Gulf has undergone severe morphological changes due to its oil and gas reserves and its connection with free waters more. it is essential to determine the coastline at different times. Landlord satellite data from 1996 to 2016 was used to survey the changes in the coastal area of Asalouyeh to the Bandar Deir, and to prepare a five class including vegetation, water, man-made, rangeland and no agriculture. For each user, the area of calculation and changes were revealed and compared with the obtained data. The statistical analyzes for the 20-year were supervised by maximum likelihood and were used to determine the changes in the comparison method after classification and the maximum probability algorithm. The results showed that the area of human land was built and no agriculture increased from 1996 to 2001, and the area of vegetation, water and rangelands decreased during the period from 1996 to 2016, which coincided with the development of the South Pars oil field, and overall, the largest increase in total use was with %393. Between 1996 and 2016, vegetation use decreased by a total of %47 and a large amount of vegetation was made into human use.

According to the capabilities of fuzzy method and its applications in a variety of engineering problems and decision-making under uncertainty, in this study, we compared the conventional methods is definitive and Mamdani fuzzy inference model. In this study, data from 30 deep and semi-deep wells in the year 1390 _ 1389 to assess the water quality of drinking plain water is used. And design a Fuzzy Inference System using membership functions and combines these functions according to the rules "if-then" fuzzy final quality of drinking water is determined. And later extended to the fuzzy and deterministic values, zoning groundwater quality index showed. The largest area dedicated to unacceptable quality for fuzzy inference method and 50. 83 percent to 51. 45 percent, is the definitive method. The desirable category in the definitive method and fuzzy 28. 76 and 26. 85 percent respectively and floor acceptable in certain ways and fuzzy, respectively, 19. 79, 22. 32 percent respectively. Fuzzy inference can be drawn that a suitable alternative method for assessing water quality associated with the uncertainty that has been taken into account.

The present study was conducted to calculate the amount of erosion in monthly, quarterly, six-month and one-year time scales. Three erosion pin networks in three aspects of north, northwest and eastern slopes in control subwatershed of Khamsan representative watershed were selected in order to measure erosion during the period of October 2015 to September 2016. Due to the monthly records of erosion pins, the possibility of erosion analyzing in the intervals of less than one year (monthly, quarterly, and sixth) was used to determine the contribution of these periods in annual soil erosion. Therefore, considering pin records, the average changes in the height of the soil and, finally, the average amount of annual erosion was calculated about 17. 22 t ha-1. Also, the participation of monthly, quarterly, and six month intervals in annual erosion was calculated to be 5. 81, 7. 33 and 9. 52 t ha-1, respectively which are about 34, 43 and 55% of annual erosion. Despite significant differences in the average amount of erosion in different time periods and their participation in annual erosion, the results of one-way ANOVA showed that the effect of time scale on soil erosion is not significant.

Today, rehabilitation of rangelands in terms of range management plans is an important step towards sustainable development. It seems that managing any rehabilitation program in rangelands will not be successful without participating the stakeholders. This study aimed to investigate the factors influencing participation of stakeholders in range management plans and evaluate the performance of biological operations in terms of range management plans in summer rangeland of Sjadrud watershed basin. For this reason, research had done in two parts; qualitative research (questionnaire) and quantitative (field operation) in 6 saman with or without range management plan. The questionnaire was conducted 117 stockholders, 34 indicators using factor analysis. Quantitative part evaluated for investigating the effectiveness of biological treatments in estimating and comparing forage production and canopy cover in the sites. In order to ensure the integrity of the variables and their suitability for factor analysis, KMO and Bartlet tests were used. Results showed that after carrying out biological operations production had increased in total sites. But the difference was not significant. KMO coefficient were 0. 781 and Bartlet coefficient were 81. 23 with 99 percentage meaningful level. results showed that economic, social, environmental and executive factors determined 81. 68 percentage of stakeholder's participation in biological treatments.

Groundwater is the most important source of water in coastal areas. Recently, due to overexploitation of the aquifer and seawater intrusion, a correct management in coastal aquifers must be applied. In this study, GALDIT and SINTACS models are used with geographic information system (GIS), in order to identify Gharesou-Gorganroud vulnerability areas. To generate, classify, weight and overlay vulnerability maps according to these two models, GIS environment is used. Geographic information system (GIS) is a useful tool to identify and assess vulnerability areas. The Pearson correlation coefficients is used to achieve an optimal model. To compare correlation results of GALDIT model and SINTACS model, GALDIT model has a higher correlation with TDS concentrations. In addition, Single parameter sensitivity analysis used to modify the GALDIT model to observe effect of each parameter on the GALDIT result model. In the study area, the result illustrated that the effective parameters in aquifer vulnerability assessment were hydraulic conductivity, depth of groundwater level, distance from the shore, type of aquifer, thickness of aquifer and impact status of existing saltwater intrusion, respectively.

Destruction of oak forests in Zagros and its impacts on the economy of Iran have motivated experts of natural resources to study its affecting factors. Researchers have found the most important of destruction is climate changes. Because of the importance of the subject، a proper method for data analyzing، decision making and recognition of potentials of the oak forest decline is needed. In this study، to map the respective susceptible zones، RS/GIS and hierarchical-fuzzy analysis techniques were applied. For this purpose، the slope، aspect، elevation classes، temperature، rainfall، dust and soil were considered as governing factors. Hence، physiographic and climatic maps were initially prepared. Due to the different impact of each factor، they were valued based on the expert judgements and and FAHP. The fuzzy maps were developed using the linear ascending and descending fuzzy and Gaussian distribution functions. Also، through the overlaying of various layers، the areas exposed to drying were mapped and classified. This research suggests that the map prepared by the fuzzy gamma distribution with a precision of 70% has the highest correlation with field data. Furthermore، southern and western areas are most susceptible to severe forest drying.