فهرست مطالب kaka shahedi

During the recent years, the occurrence of environmental hazards and the occurrence of harmful damages and significant losses caused by it has become a major challenge in most parts of the world. In order to reduce the effects of environmental hazards, consideration has been given to the resilience approach. Resilience is considered as one of the effective measures in the risk management process. It is also a community-oriented approach that improves the preparedness of local communities against instabilities caused by hazards. By knowing and understanding the level of resilience, it is possible to help reduce injuries and destructive effects with proper planning. Natural disasters reduce resilience in three ways. physical damage; including damage to residential, commercial uses, equipment and facilities. Economic damages; including loss of employment, business interruption, repair and reconstruction costs. Social harms; including the impact on people who need medical assistance and shelter. Among these natural hazards in Golestan province, we can mention facing natural disasters such as the flood of 2018. Therefore, the present research was carried out with the aim of determining the effective indicators in measuring the resilience of rural settlements in the Gorgan-rud watershed and determining the extent and importance of the social, economic and ecological resilience of the surveyed villages against the floods of the mentioned year.

The studied area is Gorganrood watershed, located in the heights of Golestan forest.  The current research is applied in terms of purpose and descriptive-analytical in terms of method. This research was done using two documentary and field methods using a questionnaire tool. The statistical population includes native residents, which consists of 126 villages and a total population of 22,942 households. Among the most populated villages in the upstream, central and downstream parts of the region, some villages were selected by two-stage cluster random sampling method based on the Cochran method. Finally, 10 populated villages and 200 heads of households were selected. The research questionnaires include three social-cultural dimensions (19 components), economic (5 components) and environmental-management (7 components). The content validity of the questionnaire was also confirmed by asking the opinions of the professors related to the subject, and then data was collected by using interviews and questionnaires. In the descriptive findings, only the individual characteristics of the respondents have been investigated. In the analytical findings, a sample t-test was used. To make statistical inferences, the mean resilience of the components was compared with the optimal mean. Kruskal-Wallis test was used in order to investigate the internal relationship between the effective macro-dimensions of the resilience of rural settlements in the face of crisis. The Kolmogorov Smirnov test was used to check the normality of the data distribution, the Friedman test was used to rank the items related to each index, and the Spearman test was used to analyze the correlation coefficients.

The results of the examination of 21 components in three economic, social and environmental dimensions showed, the social index with an average of 2.89 impact and the environmental index with an average of 2.30 had respectively the highest and the lowest impact on the resilience of the villages. Also, the highest mean of social index (3.09) was observed in Sadegh Abad village and the lowest mean (2.69) was observed in Bahlke Sheikh Musa village. The highest average of the economic index (3.36) was observed in Sahne Sofli village and the lowest average (2.49) was observed in Bahlke Sheikh Musa village. The highest average of the environmental index (2.42) was observed in Sadeghabad village and the lowest average (2.02) was observed in Aghabad village. Totally, the resilience of Sahne Sefali village had the highest level (2.89) in terms of the investigated indicators. The results of T-test samples and Kruskal Wallis of the studied villages indicated the existence of significant differences in all social-cultural, economic and environmental-management indexes (P<0.05). Also, the findings showed that the total resilience with a value of 2.65 was lower than the average and there was a significant difference between the villages (P<0.05). The results of prioritizing dimensions of resilience using Friedman's test also showed that socio-cultural factors had a higher priority than other indexes and environmental-management factors was in the last priority.

According to the results, it can be suggested that one of the most necessary activities for planning the current situation is to pay attention to the indicators that lead to increasing the level of resilience of the local watershed community. Therefore, considering that the calculated value of the resilience number is lower than the base limit (3) in different indexes, especially from the environmental-management aspect. Therefore, considering that the calculated value of the resilience number is lower than the base limit (3) in different dimensions, especially from the environmental-management aspect. Therefore, it is better to move towards creating resilient societies with high adaptive capacity by relying on crisis management. It will not be possible without recognizing and rooting the weaknesses of the society and the continuous communication of the responsible institutions and organizations with the local communities by social facilitators. At the same time, considering that the resilience of local communities against floods is a time-consuming and gradual process; establishing continuous interaction between villages with a higher resilience coefficient and villages with a lower rate in order to benefit from each other's experiences. It is suggested to hold workshops and training courses on preparedness to deal with possible floods to describe and implement them in the studied villages.

Drought as a climatic phenomenon is considered as one of the most important natural hazards, which is known for its slow onset and may have multiple effects on hydrology, agriculture and socio-economic conditions. Drought monitoring includes its severity, spatial distribution, and duration, and becomes an essential input for establishing drought risk management and mitigation plans. Many drought indicators have been introduced and applied in recent decades in regions with different climatic characteristics.

In this study, the meteorological and hydrological drought of Tajan watershed in Mazandaran province was evaluated and monitored using standardized precipitation index (SPI) and standardized streamflow index (SSI). For this purpose, firstly, the data of six stations Rain gauges and eight hydrometric stations were used in the period of 1990-2020, after removing the statistical deficiencies and completing the data of rainfall, flow rate, homogeneity and normality of the data. Finally, the meteorological and hydrological drought process was analyzed with the mentioned two indicators using Mann-Kendall test and Sen slope estimator in MAKESENS software.

The results showed that the SPI index has the highest response to rainfall on a one-month scale, so that its lowest value was at Kordkheil station with a value of -3.31, the most severe drought that occurred in April 2011. On the other hand, droughts have occurred in all rain gauge stations and their intensity has increased over time. According to the SSI index, hydrological drought has also occurred in all hydrometric stations with different intensities. The trend of these indicators also shows the increase in intensity and frequency of drought with the passage of time in the studied watershed.

In Darabkola and Kordkheil stations, the SPI index has the highest number of years of occurrence and the highest intensity of drought. In Darabkola station, the frequency of moderate, severe and very severe droughts are relatively high. Very, very severe drought in Edareh Sari station has the highest amount in terms of frequency, which indicates that there is the greatest risk of drought occurrence in the plains and plains of the basin. The results of the trend with the Mann-Kendall test indicate an increase in drought and a decrease in rainfall in the Tajan watershed. Due to climate changes, increase in demand due to increase in population and decrease in rainfall, the occurrence of drought in the future may occur with more frequency and intensity, which can cause great damage to agriculture and other parts of the region. The SSI index in hydrometric stations indicates the decrease in flow and the occurrence of hydrological drought in the basin.

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.

Drought leads to water scarcity for people and potentially causes challenge for many countries. Its effects does not just limit in arid and semi-arid This research tries to take one step identifying impacts of meteorological drought on groundwater resources in Haraz Watershed downstream region. In order to evaluate meteorological drought were used SPI index according to data which has been extract from 15 rain-gauge station in six time scale of 3, 6 9 12, 18 and 24 months and in order to evaluate changes in groundwater level according to data has been extract from 35 water wells pizometric level with mutual 29 years priod (1985-2013). All stations experienced drought event. Major drought was near to normal, moderate and less occurred sever and very severe drought in the region. In this study it was found that drought affected with a 3-month delay on groundwater resources. In this study, the highest correlation between standardized precipitation index and average groundwater level in 24 months' time scale in rain-gauge stations Nemarestagh, Miandasht and Babolsar at 95% and in the other rain-gauge stations is significant at 99% level. Regression relation between the mean level of the water table and SPI-24 of rain gauge station showed that the between study area rain gauge station, Sorkhrood station greatest effect is explained by a factor of 42.3 percent of the variance at the mean level of the water table in this study area allocated and 57.7 percent was affected by other factor.

Evaluating the sustainability of watersheds is important since it reveals the change in the status of ecosystems in spatial and temporal dimensions. Regarding this importance, current research focuses on sustainability in Sarab Seydali Watershed located in Lorestan province, Iran. For this reason, the Watershed Sustainability Index (WSI) and the conceptual framework of HELP, whose criteria are based on hydrology, environment, life and policy, were applied. Considering different variables such as water availability and its changes, acidity and electrical conductivity of water, development of sewage systems, environmental pressure index, vegetation cover, expansion of protected areas, net annual income, human development index and its related changes, level and progress of education, study and implementation of comprehensive water resource and watershed management plans and emphasis on an interactive and logical relationship with the indicators of pressure (P), state (S) and response (R), the sustainability level of the study area was evaluated . The average scores of pressure, state and response indices were estimated as 0.81, 0.6 and 0.37, respectively. Also, the average scores of hydrology, environment, life and policy criteria were 0.41, 0.58, 0.66 and 0.75, respectively. The results of index evaluation pressure, state and response showed that the watershed's stability score with a value of 0.6 is in the medium level of stability, that the two factors of hydrology and environment cause a weak level of stability, to improve and improve the stability. It is necessary to think of measures for water resources from increasing productivity, saving and building sewage systems and habitat management through extensive management of areas focusing on pressure, state and response indicators.

Sustainability of groundwater resources means ensuring the permanent availability of essential groundwater services for a long-time. This research was conducted to investigate the sustainability of groundwater resources in the prohibited plain of Behshahr- Bandar-e-Gaz by using water expoliation and green water scarcity indices. Initially, the green water deficit index was calculated based on the concept of water footprint. The water exploitation index was obtained according to the long-term average of annual fresh water resources based on the components of well and qanat discharge, total recharge and return flow. The indices were calculated for the common cropping pattern of the region (spring wheat and rice) for a 33-year period (1982- 2015). The green water deficit index was 2.68 and 2.54 for spring wheat and rice cropping system, respectively. Also, the water exploitation index was 18 percent and 17.8 percent, respectively. Increase in evapotranspiration under spring wheat cropping reduced soil water content and ultimately led to excessive instability of groundwater resources in the study area. Based on the results, the use of water expoliation index can improve the sustainability of groundwater resources in Behshahr Bandar-e-Gaz plain rather than the green water scarcity index.

Simulation of the rainfall-runoff process in a watershed is highly important from the point of view of hydrological issues, water resources management, river engineering, flood control structures and its storage. Rainfall-runoff estimation using a distributed hydrological model and the technique of GIS has become possible, practical and common. The Wetspa model is a distributed model simulating runoff and water balance that is performed at different time scales including hourly or daily basis. In this research, the discharge is simulated using Wetspa model in the Ghorichay watershed. This watershed (as one of the sub-watersheds of Gorganrood) with an area of 2481.5 ha is located in the south of Ramian city in Golestan province. The data used by the model are land use maps, soil texture, digital elevation model, precipitation, evaporation, temperature and discharge (for calibration and validation of the model). Calibration of 13 parameters was performed manually and automatically for 7 years at the beginning of the statistical period and model validation was performed for a period of 5 years. The results of the model evaluation show the accuracy of discharge simulation and very good agreement between the simulated data and observations based on the Nash-Sutcliffe criterion of 67.21% in the calibration period and 76.34% in the validation period. Also, the discharge calculated by the Wetspa model for the whole watershed was 28.31%, which in comparison with the observed discharge of 30.12% indicates a good simulation of the model.

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.

In fact determine a reliable models and selection of inputs with proper temporal delay for river flow forecasting is a key topic for watershed managers, hydrologists, river engineers. In recent decades use of intelligent algorithms and fuzzy collection theories for modeling of hydrological phenomena that have complexity and uncertainly, has been noticed by researchers. In this regard, in the present study was used adaptive neuro-fuzzy inference system (ANFIS) and different input patterns of flow discharge (with daily time steps up to 7 days ago) in order to river flow forecast of Kasilian catchment. Then in order to further investigate of this process artificial neural network (ANN) model was used and the results were evaluated using quantitative statistics including coefficient of determination (R2) and root mean square error (RMSE). In ANFIS model the results of river flow prediction was improved up 4-day step and afterward decreased while in ANN up 5-day step improved. Evaluation of quantitative statistics values for the best patterns of two models applied during validation period indicated that ANFIS (R2 = 0.60, RMSE = 0.64) had high accuracy than ANN (R2 = 0.51, RMSE = 1.74) in river flow forecasting.

Agricultural drought has become a major concern worldwide due to the severe impact on crops and the indirect impact on occupation as well as per capita income. The use of reflective remote sensing techniques to evaluate the effects of drought is recognized as one of the most efficient methods. Therefore, the purpose of the present study is to analyze agricultural drought in Mazandaran province using Remote sensing and meteorological indicators. At the first, SPI, ZSI and EDI indices were calculated at different time scales and the best index was selected based on the normal distribution method. Then, using Landsat 5, 7 and 8 satellite images, NDVI, EVI and VCI remote sensing indices were extracted and the best index was selected based on the highest correlation with appropriate drought index. Finally, using the best meteorological and remote sensing indices, the agricultural drought in Mazandaran province was evaluated in two very dry (89) and very wet (92) years for different seasons. The results showed that based on the normal distribution method, the sum of the difference from normal distribution for the SPI index is lower than the other indices. The results also showed that the highest correlation was observed between VCI spectral index and SPI meteorological index with time delay of three and six months. The results also showed that the mean VCI in all seasons of very dry year (89) for all stations was below 0.50 and maximum stations had a VCI value of less than 0.35 but in all seasons of very wet year (92) for most stations is above 0.5

The sedimentation, sediment transport, erosion and sedimentation problems are important discussions in the planning of wisdom and macro watershed strategies and management of watershed basins. The sediment collection in lower areas causes regional damage, the destruction of the pathway of the waterways, the flow of water pollution, the accumulation of streams of sediment and reducing the capacity of reservoirs of dams and environmental bottlenecks. The sediment resulting from the watersheds erosion, in addition to soil loss and its degradation results in a decrease in water quality and endangers the useful life of dams due to the accumulation of deposits in their reservoirs. In this research, Spatiotemporal variations of suspended sediment load were investigated at three hydrometric stations of Sefidchah, Gelevard and Ablou located on the main channel of the Nakaroud Basin using sediment rating curves and linear regression model through applying MINITAB and EXCEL softwares. In order to determine the best model, determination coefficient (R2) was used. The results of this study showed that in seasonal variations of spring season in all three stations with a determination coefficient of at least 82% and a maximum of 89% as the most suitable model for estimating suspended sediment load among the models studied. In spatial studies, the Ablou station located at the outlet of the watershed has the highest determination coefficient (0.934) between sediment discharge and streamflow discharge.

Soil erosion is one of the processes that directly and indirectly threatens our country's water and soil resources. Although this phenomenon is natural and it is not possible to prevent it, but it is very important to know all the erosion processes and factors that are involved in the production of sediment and the rate of erosion of watersheds. Main objective of this study is to evaluate the effects of conservation operations on the change of erosion and sedimentation class in Morid Valley Watershed in Kerman Province.

The study area is located in Darreh Morid watershed, which is located below the Halilrud basins in Baft city, central part, Kiskan village, Darreh Morid village, Kerman province. In this study, the method of recalculation of some parameters of the MPSIAC model before and after the implementation of conservation operations was used. After determining the locations of conservation operations, maps of experimental model factors were prepared before and after conservation operations, and then the amount of sediment before and after conservation operations in each sub-basin was calculated.

the amount of sediment in sub-basins 1, 2, 3 and 4 decreased from 1094.05, 697.60, 670.25 and 576.88 to 516.79, 386.70, 398.47 and 444.81 cubic meters per square kilometer, respectively. Meanwhile the amount of sediment in the whole basin reduced from 932.42 to 663.35 cubic meters per square kilometer. Regarding sedimentation class, the results showed that in sub-basins 2, 3 and 4, it was reduced from Ⅳ to Ⅲ. There is no change in sub-basin 1 and the whole basin.

After ensuring the normality of the data by Klomo-Smirnov method using descriptive statistical indices and paired t-test in SPSS17 software, the results were analyzed and significant changes were performed. The results indicated that the difference between the means is not zero and therefore the zero assumption is rejected. In other words, according to the averages, the implementation of conservation operations had a positive effect on reducing the sedimentation class and the amount of erosion, and the data had a correlation of 79%.

Prioritization of sub-watersheds and different areas has an important effect in watershed management. The purpose of prioritization of sub-watersheds is to provide a pattern for control and decrease flood hazards and evaluating the role of each sub-watershed in peak discharge of outlet flood hydrograph. In this study, Talar watershed was selected as study area, because of several floods was occurred in it and then factors affecting floods like rainfall hyetograph for different return periods, flow length, slope percentage, land use, soil hydrological group, amounts of CN and time of concentration were recognized. By combining ArcGIS software and ModClark hydrological model, the potential of flooding in Talar watershed classified into five classes: Very Low, Low, Medium, High and Very High within three return periods of 25, 50 and 100 years. The results showed that the contribution of sub-watersheds in flooding potential will be not only affected by its area but also the location of each sub-watershed and flood routing in main reach have remarkable effect on flooding regime of the watershed. Runoff production potential maps indicate that runoff production potential from downstream to upstream of the watershed is increasing and Chashm sub-watershed in Southeast of the watershed is considered as the most effective area and unit in flooding of the whole watershed because of heavy rainfall, high slope and large curve number (CN).

In this study, to simulate streamflow time series in ungauged catchments, the parameters of two HBV and IHACRES hydrological models were transfer from gauged (donor) to ungauged catchments using three main regionalization methods including Physical Similarity (PS), Multiple Regression (MR), Spatial Proximity (SP) and an integrated method (IDW-PS). This study was carried out using daily data including precipitation, temperature and evaporation related to at 21 sub-catchments in Hamoun-Jazmourian River Basin in southeast Iran over a 14-year period (2004-2016). Regionalization methods were studied under three modes: temporal (transferring across different periods), spatial (transferring between same calibration periods but different sites) and spatiotemporal (transferring across both different periods and sites). The results indicated that: (1) the more complex HBV model showed better results than the simple model, so that the average NSE coefficients in two different periods in the HBV model were 0.625, 0.57 and 0.5 for calibration, validation and the most appropriate regionalization method (physical similarity) respectively, while these values for IHACRES model were 0.57, 0.51 and 0.46, (2) multiple regression method with mean NSE coefficients equal to 0.2 and 0.24 for HBV and IHACRES models showed the worst regionalization results and (3) the HBV parameters related to snow and runoff components, were associated with highest and lowest uncertainties respectively, while for the IHACRES, the most and least robustness parameters were plant stress threshold factor, f and the proportion of slow flow to total flow, vs respectively.

Due to the urban expansion, preparing of comprehensive and detailed information, is an unavoidable necessity for urban watershed systems and also its dominant conditions in hydrological cycle to gain an integrated urban watershed management. The urban runoff pollution caused by heavy metals is the major types of pollutions in surface runoff which may cause serious health risks for biosphere and also urban watersheds. This article examines the changes in runoff quality and the amount of heavy metals such as lead, zinc and copper in Bojnoord urban watershed in two reaches of autumn and spring seasons. For this reason 52 samples were collected for the mentioned period. After preparing the samples, using atomic absorption, the amount of heavy metals were measured in terms of Pbb. The results showed that the reducing trend of these metals is as Zn>Cu>Pb and the maximum concentration of lead, zinc and copper is related to the autumn season. The location of high concentrations is in residential and commercial areas and for the samples taken from the runoff pathways and drainage network (FB2). The Pearson correlation test results showed that there is a high positive correlation between lead and copper in the autumn (R=0.954) and also between lead and zinc in the spring (R=0.641). This correlation is certified by using factor analysis and Varimax rotation.

Optimal management of water resources in a plain with land uses requires proper prediction of water resources response using efficient models. In this research, Soil and Water Assessment Tools (SWAT) model was used to simulate surface and groundwater resources in Behshahr - Bandar-e-Gaz Plain. After analysis the sensitivity, calibration and validation of the model was performed based on river flow data of 2007- 2013 and 2014- 2017, respectively. Groundwater table simulation was done by simulating the recharge rate per hydrological response unit (HRU). The results of sensitivity analysis showed that the parameters GW_REVAP, GW_DELAY, SHALLST, DEEPST, RCHRG_ DP, ALPHA_BF, SOL_AWC, CN, HRU_SLP, ESCO, USLE_P, OV_N, FILTERW and EPCO were the most sensitive parameters. In order to evaluate of the model, the performance criteria of Nash- Sutcliffe (NS) and Correlation coefficient (R2) were used. In the calibration stage, these coefficients ranged from 0.56 to 0.93 and 0.74 to 1.00, respectively, and in the validation process were in the range of 0.56 to 0.84 and 0.66 to 0.92, respectively, indicating the acceptable accuracy of the model in river flow simulation. Comparing the observed and simulated water table depths, NS (0.81) and R2 (0.91) coefficients indicated the capability of the model to simulate groundwater level. According to the results of the water balance analysis, the most of the total water input to the plain, it’s 60% was used for evapotranspiration and it’s small parts as 18% and 22% allocetaed to surface runoff and infiltration, respectively.

Changes in plot size can be determine its effects on parameters changes of runoff and soil loss. On the other hand, the generated runoff in eroded soils is one of the most important obstacles and challenges of human in conservation of water and soil resources and it is also a threat to well-being and life. One of the most important of controlled factors of surface runoff and increasing soil infiltration is the application of conditioners or amendment materials on soil. But it should be noted that the size change can also control the runoff and soil loss variations. Therefore, the present study was carried for the effect investigating of size change in laboratory plots in two sizes of 0.5 × 0.25 and 1 × 0.5 m2 using application of organic manure with rates of zero (control treatment) and 62.5 and 125 g m-2 (conservation treatment) on changing time to runoff, runoff coefficient, soil loss and sediment concentration. The obtained results showed that the plots with size of 0.5 × 0.25 m2 and the application of organic manure with rate of 62.5 g m-2 had the little effect on the increasing time to runoff compared to control treatment. But, time to runoff increased with increasing plot size and also rate of organic manure. The effect of plot size on parameters of runoff coefficient, soil loss and sediment concentration, organic manure on parameters of time to runoff, runoff coefficient and soil loss and interaction effect of size change and organic manure on parameter of soil loss was significant at level of 99 percent. Also, in plot with area of 1.0 × 0.5 m2, the changes of time to runoff and runoff coefficient, soil loss and sediment concentration for organic manure with rate of 125 g m-2 toward 62.5 g m-2 were 72.83, 53.52, -212.27 and -142.92 2.12 percent, respectively. While, the changes of studied parameters for plot of 0.5 × 0.25 m2 were 594.24, -212.63, 4.06 and 13.70 percent, respectively.

Iran is one of the countries in the Middle East that is facing a shortage of renewable water resources. As one of the governmentchr('39')s socio-economic policies, the emphasis has been on the optimal use of renewable resources, in particular refined human and industrial wastewater. One of the limiting factors of using these wastewater is the presence of heavy metals in them. Therefore, soil remediation is important to reduce this pollution or to deactivate heavy metals.  This study was conducted to investigate the effect of bentonite modification on soil elements concentration irrigated with municipal wastewater under cultivation of Alfalfa and clover in a completely randomized design. In this study, essential and toxic elements of the plant, soil properties and elements in soil under different effluent ratios (0%, 25%, 50%, 75% and 100%) were investigated. Also, due to the presence of heavy metals in wastewater, bentonite modifier was used as immobilizer of heavy metals in soil at two levels of 1% and 3%. The results showed that 100% effluent-3% bentonite treatment had the highest amount of soil organic carbon, organic matter, lime, pH and EC for both alfalfa and clover species (p<0.05). Also, increasing the level of effluent application significantly increased the concentration of essential elements (NPK) in soil and plants. On the other hand, application of 3% bentonite resulted in a significant decrease in the toxicity of lead and cadmium in plants and soils. In general, it can be concluded that application of proper wastewater treatment can be used as a potential source of water to enhance plant growth and yield, as well as the use of bentonite as an immobilizing agent of heavy metals in wastewater in forage production methods.

Landslides are one of the major types of slope instability which cause enormous financial losses and casualties; therefore, it is imperative to consider them in the study of geomorphology, erosion and sedimentation in important watershed. The aim of the present study was to investigate and rank the landslide susceptibility using a random forest method in the Sadat Mahalleh Watershed, Sari. Elevation from the sea level, geology, land use, slope (degree, direction, shape and length), distance from linear elements such as faults, streams and roads, normalized difference vegetation index and slope form were considered as effective parameter in the landslide occurrence. Zoning landslide sensitivity was achieved by coding in the R and GIS10.3 soft wares. In order to determine the weight of each of the factors and classes effective in zoning the landslide sensitivity and validation of landslide potential prediction maps, the abundance ratio method and the receiver operating characteristics (ROC) were used. The results indicated that among the effective factors, vegetative cover and land use, had the most paramount impact on the landslide occurrence in the study area. A landslide sensitivity map was prepared using the random forest method by dividing into five class, namely: very low (3.85%), low (5.38%), moderate (23.08%), high (50%) and very high (7.69%) sensitivities. Validation of the results of the landslide sensitivity zoning maps, using the relative factor characteristics index diagram, indicated that the area under the curve (AUC) for random forest method was 0.709 and its standard error was 0.10. It is reasonable to claim that the forest method provided an acceptable accuracy for mapping the landslide sensitivity. A landslide sensitivity map provides prone complete and accurate information for natural resource managers to detect the landslide areas.

Assessment of metals absorbed to suspended solids in urban floods, allows managers to take measures to improve the quality of the urban environment. This article examines the changes in the concentration of heavy metals such as lead, zinc and copper in suspended load of runoff from the Bojnourd urban watershed in autumn and spring seasons. For this reason, 52 samples were collected. After preparing the samples, separation of suspended sediment using the Whatman filter paper and then weighing the amount of sediment in runoff, using atomic absorption, the amount of heavy metals dissolved in runoff and heavy metals absorbed to suspended solids in runoff were measured in terms of ppb. The results showed that the amount of suspended sediment weight is higher in spring than autumn. Results indicated that the maximum concentration of insoluble heavy metals and attached to sediments is more than soluble heavy metals in runoff. On the other hand, the results revealed that the mean maximum concentration of zinc and copper, except lead attached to sediments, is higher in the spring than autumn and the spatial concentration of zinc and copper in samples of runoff suspended sediments from Sandalabad Stream (FC3S) is higher. While on the lead, concentration for the samples taken from the runoff pathways and drainage network (FB2S) was higher. However, the difference in location of data for heavy metals absorbed to suspended sediments is not statistically significant. The Pearson correlation test results showed that there is a positive but low correlation between lead and zinc (r =0.166) in the autumn and the lead and copper (r=0.271) in the spring. Significance of this correlation is certified using hierarchical cluster analysis method.

The presence of water is an important and fundamental factor for life. In addition, water supply is a principle in the development of societies. The unfavorable trend of water resources in the world and predictions reported the critical state of water, prompted researchers and international institutions to conduct extensive studies on water resources and related management. Due to the special sensitiveness of water resources management, various indices have been developed and presented to evaluate the current situation. In this study, Falkenmark index have been used to examine water scarcity using population rate and water consumption per capita in the Gorganroud basin. Gorganroud region is one of the lushest regions located north of Iran on the east side of Caspian Sea. According to Falkenmark index, which obtained to be more than 3000 in this area, shows that this basin is in good condition and no water scarcity is observed in it. Agriculture part consumes most of water supplied in this region which is followed by urban use or drinkable water and industrial use almost needs very low source of water.

Landslide is an important geological hazard and one of the natural disasters that are constantly happening around the world. The factors that cause landslides are numerous and complex. Today, due to the importance of landslides and the effects of not paying attention to this issue, risk prevention has become an important tool in land use planning and management. Given the sensitivity and importance of this issue, the preparation of zoning maps of landslide sensitivity is very important and should be considered. These maps show landslide-prone areas and safe areas. Effective use of the landslide map can reduce the potential damage to the event and thus avoid many hazards. Landslides are natural events, but they can become dangerous and cause casualties and damage to man-made and natural structures.

The study area is the Neka Watershed located in the east of Mazandaran Province. To study landslides in this study, from nine maps including land use, slope, geology, slope direction, land curvature, distance from faults, communication routes, sewage from the river, and rainfall were selected and each map was extracted to produce the final landslide map. Finally, the maps were finalized in GIS software and the final map was prepared using the fuzzy logic method. In the fuzzy model, each of the pixels in the map is given a value between zero and one. To perform fuzzy in ArcGIS software the fuzzy Membership tool was applied. In this research, the Shannon entropy method was also used. Finally, the landslide map was extracted and evaluated. According to the final map and its studies, landslide-sensitive areas were identified.

Various factors, in relation to each other and in relation to local characteristics, cause domain instability. Instability factors with different contributions to the occurrence of mass movements, especially in the occurrence of landslides. To study landslides in this study, from 9 maps including land use, slope, geology, slope direction, land curvature, distance from the fault, communication paths (sewage from the road), sewage from the river and rainfall, and the map of each separately The final landslide was extracted to prepare the map. The maps were prepared in the final GIS software and the final map was prepared using the fuzzy logic method. The fuzzy model was performed using Arc GIS software and each of the pixels in the map was given a value between zero and one. The Shannon entropy method was used in this study. Finally, the landslide map was extracted and evaluated. According to the final map and its studies, landslide-sensitive areas were identified.

Based on the knowledge-based approach, the evaluation of several parameters such as geology, slope, land cover, slope direction, land curvature, rainfall, distance to flow, distance to road, and distance to fault were overlayed and the landslide map was extracted. A numerical scale (1-5) from very high to very low impact was used. Areas with high and very high sensitivity have been recorded in areas without vegetation and with high slopes and high rainfall. Sub-watersheds N2 and N1 are ranked 1st and 2nd, respectively, in terms of high landslide potential. The reason for the high intensity of landslides in these two sub-watersheds is low vegetation and a high slope.

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.

Soil is the main factor in food production, but it has always been under the destruction influence, therefore the reduction of soil loss is more important. In spite of numerous studies in prevention field of soil loss, the full understanding of this phenomenon and its reduction has a long way to come. Studies showed that today the various conditioners are used with aim of water and soil conservation in worldwide. Organic conditioners are the materials that these can cause the increasing infiltration and decreasing runoff and soil loss. Runoff and sediment yield is affected by spatial changes of soil properties and soil ability in runoff and sediment yield are not constant over time. Therefore, the innovation of present study conducted the study of poultry manure effect in process of soil and water conservation on parameters of time to runoff, runoff coefficient, soil loss and sediment concentration in time period of 24 h, 3, 6, 9 and 12 months.

In present study for measuring the runoff and soil loss amount used from 28 plots using dried-air poultry manure in laboratory conditions. The poultry manure applied with two amounts of 5 and 10 t ha-1 that this was directly distributed with hand on surface soil. Then, the experiments was conducted in control treatment (before application of poultry manure) and conservation treatments (after application of poultry manure) with three replications. The experiments simulated in control plots and conservation plots using rainfall simulator for rainfall intensity of 50 mm h-1 and slope of 20 percent for collection of runoff and sediment.

The results showed that the poultry manure with two amounts of 5 and 10 t ha-1 in time periods caused the increasing time to runoff and decreasing runoff coefficient, soil loss and sediment concentration. The poultry manure of 10 10 t ha-1 and time period of 12 month had more effect on increasing time to runoff with rate of +19.6 percent, also the most decrease amount in runoff coefficient and soil loss with rates of -14.11 and -19.00 percent, respectively. While, the treatment of poultry manure with rate of 5 t ha-1 in time period of 24 h presented the most decrease in soil concentration with rate of -9.93 percent. The results also showed that the separate effect of poultry manure on time to runoff and soil loss was significant in level of 95 percent. Also, the separate effect of time period on time to runoff was significant in level of 99 percent and on runoff coefficient, soil loss and sediment concentration was not significant.

Organic conditioners can cause the reduction of runoff and soil loss. However, the material role of organic amendment of accessible and environmentally friendly less has been attention. Also, use from organic manure is one of the most desirable methods in reducing use costs from chemical manure and also these destructive effects on soil and environment.

Flood is one of the natural hazards that causes numerous financial and life damages each year. Therefore, flood potential prioritizing is crucial to reduce the damages caused by it. The aim of this study was to evaluate the efficiency of the Analytic Hierarchy Process (AHP) in flood potential prioritizing of Barajin sub-catchments. So, flood potential of sub-catchments was determined using AHP and the results are compared with the outputs of the HEC-HMS model as observed data. The results showed that in addition to full compliance of the two maps, there is a significant correlation (0.9299 and 0.934) between flooding potential ranks and peak flood discharge ranks with the return periods of 25 and 50 years of sub-catchments. The weights of AHP were also showed that in the flood of sub-catchments, generally, hydro-climatic criteria (weight = 0.65) is more important than morphometric criteria (weight = 0.35); and the rainfall intensity is the most important sub-criteria (weight = 0.373). Based on the final ranking, sub-catchments of 5, 3, and 4 that are located in upland and mountainous areas, have high flood potential due to the high weight of tow sub-criteria, one rainfall intensity, and the other 25-years rainfall. The results of this study could be a good guide for controlling floods of the study area in addition to understanding the processes governing the watershed.