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

Arsenic, one of the most critical environmental toxins, accumulates in plant and animal organs through root absorption in plants and subsequent ingestion by humans via the food chain or direct consumption of contaminated water. Reports have highlighted the contamination of regional drinking water sources in Bijar city, Kurdistan province, with arsenic and its adverse effects on local residents. Therefore, this research aimed to investigate the distribution of arsenic in the water and soil sources of the region and evaluate the capacity of native pasture plants to absorb and accumulate this element.

Arsenic concentrations were measured in surface and subsurface waters of a 360 km2 region using the atomic absorption-graphite furnace method. The distribution of arsenic in the contaminated area was mapped using the ArcGIS program. Three sampling areas with varying pollution intensities (A > B > C) were selected. Soil samples and aerial parts of 13 plant species were collected and analyzed for arsenic concentrations, enabling a comparison of different plant species' ability to absorb arsenic.

The intensity of arsenic contamination in surface water, soil, and plants studied in this research exceeded typical concentrations of arsenic in water, soil, and plant sources. Total arsenic concentrations in water samples ranged from 4.5 to 280 μg l-1 and correlated with electrical conductivity, total dissolved solids, and total hardness (p < 0.001). Arsenic concentration in the soil of area A (Ali-Abad village) exceeded 2059 μg g-1 of dry soil, with contamination decreasing with distance from area A. A high correlation was observed between the intensity of water and soil pollution (R2=0.84). Arsenic concentrations in the aerial parts of 13 plant species with three replications varied depending on the plant species and the intensity of soil contamination (0 to 47.8 μg g-1). The intensity of soil contamination was on average 27.66 times higher than the amount of arsenic accumulated in the plant, indicating the high resistance of native pasture plants in the region to arsenic toxicity.

Field monitoring revealed that 45% of water resources in the sampling areas exceeded the national drinking water standard for arsenic (50 μg l-1), reaching 78% according to the World Health Organization standard (10 μg l-1). Concentrations of parent materials containing arsenic compounds were higher in areas A and B than in area C, with decreasing concentrations further from area A. The sampling region significantly influenced the average arsenic concentration in water and soil samples (P < 0.05). Arsenic uptake by the plant samples exceeded typical concentrations (0.1 to 3 μg g-1), with the highest mean arsenic concentrations found in the leaves of Astragalus bisulcatus, Chenopodium album, and Mentha longifolia, accumulating more than 47.8, 35.5, and 22.5 μg g-1, respectively. The study demonstrates heavy contamination of water, soil, and plant resources in the region, with most surface water resources utilized for agricultural irrigation, animal consumption, and occasionally drinking water for village residents. The entry of arsenic into the human body, directly or through the food cycle, poses a severe health risk to the region's residents, necessitating immediate intervention measures.

The source of many qualitative and quantitative problems of water resources is the activities that are done in a watershed. Therefore, reviewing the planning strategies of watershed can lead to the reduction of these challenges therefore it is necessary to assess the effects of operating of these strategies before implementing them.

This research is carried out in the Hashtgerd basin is located in the central part of Alborz province. After making the semi distributed hydrological model (SWAT), this model has been developed to convert quantity and quality of surface water resources. For this purpose, the statistics of hydrometric stations Fashand, Dehsomeh and Najmabad and qualitative data of nitrate of the index station were calibrated and validated as control points. After model sensitivity analysis, its calibration process was conducted using SWAT-CUP software with SUFI2 algorithm and 500 iteration and the best values of selected parameters were obtained. Then, impact of implementing management scenarios are required such as modifying cropping pattern and improving irrigation methods to enhance the agricultural efficiency for improving agricultural state and reducing the contaminations. At last assessing the vulnerability of the Hastgerd aquifer using seven DRASTIC parameters by overlaying layers, ranking and weighing was assessed.

The results of the monthly surface runoff simulation were tested by Nash-Sutcliffe indicators and coefficient of determination. The results above 0.7 which showed that the simulation was done with good precision showed that simulation was done with proper precision(results over 0.7). The results of the Nitrate calibration and validation show that the NS was 0.83 and 0.7 and the R2 was estimated .87 and 0.89. These values indicate the proper performance of the model and approve high correlation between the observed and simulated data. After determining the vulnerability map of the Hashtgerd aquifer along the density of wells correcting the weights of the model layers, the central part of the plain is the most vulnerable.

Two management scenarios were modeled including the change in the cropping pattern and improvement of the irrigation efficiency to assess the quality and quantity variation in surface resource. It was indicated, by modifying the cropping pattern and reducing water exploitation, the amount of surface runoff was increased. However, the density of Nitrate was reduced by 5 to 20 percent in different months. With implementation of scenarios, the water consumption in the agriculture sector will be reduced from the 85.3 MCM to 59.8 MCM. The final vulnerability index of the aquifer varied between 44 to 90 by using DRASTIC method.

Rainwater harvesting systems is an effective method for the utilization of surface water resources in rural and agricultural areas especially and can be considered as a factor for the development of these areas. However, since site selection and identifying suitable places to implement this technology in rural areas is one of the most important and basic steps of using these systems, the main purpose of this study was to determine the location of rain water harvesting systems for sustainable rural development in Northern Savadkooh county. This research was carried out using remote sensing technology and using satellite images, meteorological organization data and geographic information system and Analytical Hierarchy Process. For this purpose, data were collected through pair wise comparison questionnaire by 16 samples among water sources and the paired matrix of criteria and the weight of each was estimated. Then the layers of each criterion were combined and the final layer of susceptible areas was determined. Based on the results, this county was classified into four categories: unsuitable, medium talent, good talent and suitable talent. According to the talent of the region, this city is classified into four categories: unfit, medium talent, good and suitable, and the suitable and good areas cover a total of 57.2 percent of the study area. Applying appropriate methods of rainwater extraction can be used to store rainwater and optimal management to prevent wastage of surface water.

The salinity of irrigation water resources combined with improper irrigation and drainage management is considered one of the most important threats to the sustainability of the agricultural sector in irrigated lands of the country. According to an overall estimate, about half of the country's irrigated farms have salinity problems at different levels. Given that no up-to-date and accurate report on the salinity status of agricultural water resources of Iran has been prepared so far, this paper decided to do this with the help of the latest statistics and information available at a national scale. For this purpose, the quality (salinity) data of agricultural water resources related to Iran Water Resources Management Company and also the results of previous studies on the quality of surface and underground water resources were used. The results of data analysis, which was conducted on 44.5 billion cubic meters of groundwater used in the agricultural sector, show that the average electrical conductivity of these resources is around 2.0 dS.meter-1. of which, about 31% (equivalent to 13.8 bcm), as well as about 20% of the surface agricultural water resources (equivalent to around 3.6 to 4.4 bcm) have salinities higher than the average. Concludingly, the possible effects of salinity on crop yield have also been provided, as well as proper solutions to overcome the salinity problems of irrigated agriculture.

In this study, a fuzzy multi-objective planning model was used for the optimal allocation of irrigation water and land use under multiple uncertainties. The effect of effective rainfall for determining the irrigation requirement of cultivated crops and also the limitation of surface water and groundwater resources were taken into account in the developed model in the Talash study area, which is located outside the Sefidroud irrigation and drainage network. The study area of Talesh was divided into three irrigation areas: Astara, Talesh, and Rezvanshahr. Then, the results of the optimal model were investigated at different levels of α-cut (0, 0.2, 0.4, 0.6, 0.8, and 1). Allocated amounts of surface water and groundwater showed that maximum shortages occurred in June and July in Talash area, So that the shortage of Talash area in the upper and lower bounds of a-cut=0.8 was 1.7 and 2.7 times more than Astara area as well as 1.2 and 1.8 times more than Rizvanshahr area, respectively. The optimal ratio of groundwater consumption to the total allocated water in Astara, Talesh, and Rezvanshahr areas were 13.4%, 58.1%, and 28.5% respectively. Also, 100% of the allowable groundwater is consumed in most of the dry months of the year. Due to the unavailability of surface water resources to many farmers in this area, proper approaches should be given to the farmers for more access to surface water. Therefore, the results of this study could be a warning for the regional manager and planners to consider this issue in future planning to select the best decision regarding the use of the type of irrigation water resource.

Changing rainfall patterns and increasing population in Mazandaran province has caused the correct use of surface water resources in various sectors, especially agriculture is inevitable. Despite appropriate rainfall potential in Mazandaran province, there is no regular plan for the management of surface resources. While using the ab bandan, some of the problems of the water sector in this area can be solved. To evaluate this issue in the present study, the SWAT model was used in the Tajan watershed from 2000 to 2017. First, the efficiency of the model and its results were evaluated as the current situation, then the scenario was implemented without considering the ab bandans. The SUFI2 algorithm in SWAT CUP software was used to analyze the uncertainty, calibration and validation of monthly discharge and sediment at six selected stations. The performance of the model was evaluated by coefficient of determination and Nash Sutcliffe. R2 coefficient in runoff and sediment simulation was obtained in the range of 0.68_ 0.87 and 0.62 _ 0.79, respectively. Also, the NS coefficient for runoff was in the range of 0.52 _ 0.72 and sediment was in the range of 0.58 _ 0.74. The results showed that the model had a satisfactory performance in simulating discharge and sediment. The findings of the scenario show that in the absence of ab bandans, runoff discharge and sediment output will increase by 16.3% and 17.5%, which indicates the inhibition of discharge and sediment by these structures. Also, by examining this scenario, during the floods, these structures had an effective role in flood control by inhibiting 17% of runoff and 27% of sediment. Due to the capacity of ab bandans in controlling discharge and sediment, it can be planned to manage surface water resources control floods by increasing the surface area and volume of these structures.

Hydrological models are useful tools in water resources planning, but some of them do not have satisfactory performance on a regional scale. Hydrological models are appropriate for a specific spatial scale and the lack of input data is a limiting factor in the modeling. One way to overcome this limitation is by using a flexible comprehensive model in different watersheds. Since surface and ground water have dynamic interaction in environmental ecosystems and form a combined water resources system so, the application of two general methods including fully integrated and coupled regions has been evaluated in this research. An investigation of these methods showed that the major focus in most studies is on increasing the accuracy of recharge and evapotranspiration rates in simulation. The results showed that the simultaneous use of SWAT and MODFLOW models to understand the hydrological conditions in a region has been able to cover the defects associated with the semi-distributional and distributive constraints of two models, simulating the surface-groundwater and the interaction between the aquifer and river. This method can provide useful information about the water balance of the basin and help to plan water resources more accurately

In this study, optimization of location of sampling stations for water quality of river system using information entropy theory in Lavasanat and Tehran-Karaj catchments with 11 sampling stations for 12 water quality and quantity variables for a statistical period of 21 years has been considered. First, using the discrete transinformation entropy theory, a T-D diagram was drawn for each variable, which indicates the distance between stations and transinformation. Then, using analytical hierarchical process (AHP) method and according to water consumption for agriculture and drinking, the weight of all variables was determined using Expert Choice software. The optimal distance between monitoring stations was obtained based on the total weight of each qualitative variable at its optimal distance of 14.1 km. Also, the optimal distance was calculated by fuzzy AHP method, which was 13.83 km. Then different scenarios were performed to eliminate or increase the number of sampling stations. The results show the efficiency of discrete entropy theory in combination with multi-criteria decision-making method in optimizing the number and distribution of water quality monitoring stations in river systems.

In recent years, toxic and chemical effluents from agricultural and industrial activities have entered into surface waters without considering environmental considerations, which has caused water pollution, contamination of river sediments and many environmental hazards. In this study, the concentration of four heavy metals of arsenic (As), chromium (Cr), cadmium (Cd), and lead (Pb) in water and sediments of Haraz River in Mazandaran province was investigated using Contamination Factor (CF), Pollution Load Index (PLI) and Geoaccumulation Index (Igeo). The results showed that the concentration ranges of arsenic (AS), chromium (Cr), cadmium (Cd), and lead (Pb) in water are 3.03- 3.99, 2.55-3.92, 1.94-2.42, and 3.96-5.3 mg/lit, and in sediment are  2.12-5.15, 29.91-32.71, 1.02-1.03, and 6.62-9.46 mg/kg, respectively. The concentration of heavy metals in downstream sites (S7 and S8) were higher than the standard drinking water, due to the disposal of waste, untreated effluents from various industries and excessive agricultural activities. The pollution load index (PLI) of  heavy metals in sediment samples was in low and medium pollution level and the Geoaccumulation Index (Igeo) in sediment samples was in the level of no and medium pollution. This study suggests a continuous monitoring of heavy metals in water, sediments and other aquatic biomasses, which is crucial in Haraz River to ensure the environmental safety adjacent to the river.

The most important causes of water shortage in today's world are population growth, reduced rainfall, land use change and urban development. Water is essential for many aspects of economic and social development, agricultural, urban and industrial uses and is an important component for the environment. In other words, water is considered as one of the most valuable natural resources and the most important issue and challenge in this century. Increased water demand due to population growth, development of agricultural and horticultural lands and in general the quantitative and qualitative limitations of harvestable water resources as one of the most important challenges in water resources management and planning, led to the combined use of surface water resources and Groundwater seems to be essential as the two main sources of water supply. Integrated management of surface and groundwater resources is the combined exploitation of two sources in which surface and groundwater resources are used together. The main goal of integrated management is to achieve sustainable development. Therefore, the principles of integrated management are based on the combination of supply management with demand management, which also considers environmental, social and economic aspects. Considering that most of the water needs in our country are met through aquifers, so knowing the status of aquifers can help in proper management of water resources in the region. One of the solutions to deal with the issue of over-extraction from groundwater resources is the use of integrated surface and groundwater management. Due to the decrease in precipitation, especially in recent decades, the reduction of surface and groundwater resources and the uncontrolled abstraction of aquifers and the increase in demand have resulted frome this. In such situations, the need for accurate management of water resources is strongly felt, and the tools of this management and careful planning are the extraction of relationships between factors such as rainfall, groundwater level, consumption, and so on. Marand plain is one of the forbidden plains of East Azerbaijan province, which lacks permanent surface water resources. Therefore, excessive exploitation of groundwater resources has caused a sharp drop in water levels in the region. Therefore, the study of surface and groundwater in this area in order to achieve a proper management approach seemed necessary. In this research, the consumptions of Marand plain were evaluated by using the simulation model of WEAP and GMS. The calibration and validation of these two models respectively were done based on a ten-year-period of 2002-2011 and a of 3-year period of 2012-2014. Then, different managerial scenarios were considered providing the drinking water in Marand. The scenarios were defined through limitations in using wells, increase the efficiency of irrigation in agriculture section, construct a sewage system, and two combinations of the above mentioned scenarios, in order to reduce the water demand and improve the condition of aquifers. Predictions were made for a 23-year-period according to these scenarios and its effects on the studied water sources. Results indicated that simultaneously utilizing different methods of water management is better than using a single method, which leads to the improvement and revival of aquifers and reduction of water extraction from different sources. The reliability index of providing water in the compound method, for different sections of urban drinking water, rural, agriculture, and industry was calculated at 100, 100, 64.7 and 74.6, respectively. By the compound scenario, the water level would have 16 meter reduction, while the aquifer could be improved with the yearly recharge of 0.29 million square meters and have a relative balance between withdrawals and recharges of the aquifer.

The study of infiltrated solutes and their pathways toward the rivers is very important in water quality studies of rivers and groundwaters well as the management of fertilizers and pesticides in the farms. In this research, the transport of infiltrated solutes toward the connected groundwater and surface water was experimentally studied. The concentration of solutes and the discharges were measured separately in the groundwater and surface water, using a creative modification in the current experimental model of 150 cm length, 70 cm high and 20 cm width. Potassium permanganate was used to observe the pollutant cloud movement and sodium chloride was used to measure the amount of transported solute. Potassium permanganate was injected in places of 15, 35, and 55 cm far from the river while NaCl was injected in places of 15, 35, and 65 cm far from the river. In all experiments, the hydraulic head difference was 33 mm in the model. The tracer study showed that the capillary zone affects solute transport and the tracer starts to move horizontally above the groundwater table. When the NaCl injection starts, due to changes in the boundary condition, the river discharge decreases while the groundwater discharge increases. Continuous measurement of EC in groundwater and surface water showed that the river is affected more than the groundwater by receiving 60% of the injected salt.

During the last decades, arid and semi-arid regions has faced a severe problem of depletion of groundwater resources due to the over-exploitation of the aquifer. Moreover, groundwater and surface water are not isolated components of the hydrologic system, but instead interact in a variety of aspects in which development of one commonly affects the other. Additionally, the interaction is often complicated by agricultural activities including surface water diversion, groundwater pumping and irrigation. This study presents an integrated SWAT-MODFLOW model that couples land surface hydrology and groundwater hydrology to determine spatial groundwater percolation patterns considering allowable groundwater pumping rates for the Neishaboor watershed, Iran. Within the integrated model, the pumped groundwater is applied as irrigation to the cultivated fields within the SWAT model, with deep percolation from the soil profile bottom applied to the MODFLOW model as recharge. The model is tested against observed stream flow and water table elevation, with model output then used to assess and quantify spatial-temporal patterns of groundwater recharge to the aquifer.

The recently developed SWAT-MODFLOW modeling code simulates spatially-distributed hydrologic processes in the coupled land surface / aquifer system, with SWAT simulating land surface, soil zone, and stream flow routing processes and MODFLOW simulating groundwater flow and groundwater/surface water interaction processes. Modifications which is done to the modeling code includes: 1) Linking pumping from MODFLOW cells to SWAT HRUs for groundwater irrigation and 2) Imposing shallow water table percolation and lateral flow conditions for SWAT HRUs when the MODFLOW-simulated water table is within the soil profile of the HRU. The integrated SWAT-MODFLOW framework is tested in the Neishaboor watershed (9157 km2) for the 1998 to 2011 time period. Climate of the region is classified as semi-arid, with an average annual precipitation of 265 mm that varies considerably from one year to another. The mean annual temperatures changes from 13°C in the mountainous area to 13.8°C in the plain area and the annual potential evapotranspiration is about 2,335 mm. The main crops that are grown in the watershed is irrigated and rain fed wheat during fall and winter and corn silage during summer. Regarding previous studies, about 93.5% of the groundwater withdrawals in the Neishaboor watershed are consumed in agriculture, mostly for irrigation. Therefore, irrigation practices play a crucial role in the water resources balance in the study area. Within the integrated model, the pumped groundwater is applied as irrigation to the cultivated fields within the SWAT model, with deep percolation from the soil profile bottom applied to the MODFLOW model as recharge. The SWAT model was calibrated and tested in SWAT-CUP for the 2001-2009 and 2010-2011 periods, against stream flow and developed model was calibrated manually against groundwater level data.

Annual average recharge, calculated from the daily recharge values pass from SWAT to MODFLOW, demonstrating higher recharge rates in the alluvial fans and upland plain. Observed and simulated stream discharge in four hydrometric stations demonstrate good similarity results with the observed hydrograph. The NS values for monthly discharge rates are considered acceptable, however, the field-estimated stream flow estimates contain a high degree of uncertainty. Simulated cell-wise groundwater hydraulic head at the end of the simulation is compared with observation values with the highest water table elevation occurring in the north east and low water table elevation occurring in the outlet. Comparing observed and simulated average groundwater levels at the 48 monitoring wells, the deviation from the 45-degree line is less than 2.5 m for over 73% of the circles. The manual calibrated model can capture the main temporal trend. Overall, the model well captures the long-term characteristics of the regional groundwater level.

In this study, a new coupled model, referred to as SWAT-MODFLOW was used to model a dry and semi-arid region with a complicated irrigation system with groundwater pumping. A comprehensive model, will enable accurate simulations of stream flow and water table fluctuations in watersheds and aquifers respectably. In short, surface water infiltration is passed from SWAT to MODFLOW based on the contributing areas of the HRUs to the groundwater grid. Pumping agriculture water is then calculated and passed back to SWAT. The need for such a model is highlighted by the Neishaboor basin, where the agriculture is completely based on groundwater pumping. The case study in the Neishaboor basin demonstrated the applicability of the model for large, dry basins. The model will be used to determine best management practices for groundwater pumping in the region.

In this study, water exchange in normal and severe drought conditions was also investigated. Based on the historical time series of zayanderood stream flow in Sadtanzimi, the water years 1373-1374 and 1379-1380 were selected as normal year and severe drought condition, respectively. By derived equations, outflows of three reaches were obtained under normal and drought condition. Based on the results, in normal condition net exchange of surface water was negative in three reaches, and only a small amount of 5 million cubic meters per year has been added to surface water in the second period. The results in normal year showed that surface water was fed by groundwater in the first reach and in the other two reaches fed groundwater. Compared to the normal water year, significant changes were observed in the exchange of surface water with groundwater and atmosphere in severe drought conditions. In the first reach, surface water gain by groundwater was observed, which this increase is 17% of outflow of this reach during drought conditions. During the drought, only the first period has not faced with shortage. The flows and water exchange in this situation have been such that the observed outflow of the three studied reaches is reduced by half the inflows. Surface water of the first reach has net gain in drought conditions. While under normal conditions, this interval was purely water withdrawal. Duo to the lack of accurate data on withdrawals and return flow, these components of the surface water balance were considered as annual average. However, the obtained results and their comparison with the data and information in the previous studies showed that the proposed method is a suitable toll for assessing the exchange of surface water with groundwater. Therefore, in future studies it is suggested studying this method with more accurate data on exploitation and return flow. Keywords: Surface water and Groundwater Interaction, Streamflow, Mass balance, River reac

As urban agglomerations grow, they face management challenges in terms of providing water and sanitation services to an ever-growing population, the impact of urban development on natural resources and the effects of extreme weather events. Simulation scenarios of future climate change using Global Circulation Models showed that the surface water supplies in Central Asia will be reduced due to reduced thickness of glaciers. Iran is also one of those arid regions. Therefore, the performance of management operation on water resources is mandatory. Coordinated management of the surface and groundwater resources guarantee the water supply in face of water stress situations. One of the most important instances of management plans is to estimate the relationship between these two sources of water. The groundwater recharge methods vary from small-field scale to large irrigation schemes and from simple water balance estimations to complex recharge models. In this research, for the first time, the isopotential map and Lohman method have been used for calculating the recharge and discharge between Zayandehroud River and the Isfahan aquifer. The semi-arid Zayandehroud River Basin is one of the most strategic river basins of Iran. The Zayandehroud River, as one of main river in central Iran is selected as the domain for the present study. Originated from the Zagrous Mountains, the Zayandehroud River with an average flow of 1400 million cubic meters (MCM) per year is the most important available water resource for domestic, industrial and agriculture consumptions in the basin. The study area includes an unconfined aquifer which its slope is from the South to the North and West to East. The elevation of Isfahan is about 1570 meters above sea level and its annual rainfall is about 160 mm. Zayandehroud River enters in the west area of the city, with water level of height around 1587 meters and exits in the East of Isfahan with water level of height 1560 meters. Over recent years in Zayandehroud basin, excessive amounts of surface water and groundwater have been used for different consumptions. Therefore, Zayandehroud River is alternately dry and wet periods. This phenomenon has been significantly affected the hydrologic balance of the basin and resulted in marked decrease in groundwater level. In this study, in both dry river and wet conditions of the Zayandehroud River in the Isfahan reach, the groundwater table was measured at 23 points. Then, using the geophysical and geotechnical data sets, the hydraulic conductivity of the aquifer was determined. Finally, using the Lohman equation, the amount of water transported from each aquifer section was calculated. The difference between flow rate for mentioned periods (i.e. River water less and River wet periods) is the role of Zayandehroud River in recharging the Isfahan aquifer. The results show, when the river was dry, the recharge point almost is relevant to southern part of Isfahan and the discharging point is related to the north western and north eastern parts of the city. In this situation, the river plays no role on Isfahan aquifer. In the river wet period, the river recharges Isfahan aquifer in both sides, from upstream to Shahrestan Bridge area. After Shahrestan Bridge, the recharging behavior of the river is the same as dry period. According to the obtained results in the dry period of the river, the groundwater flow rate in Isfahan aquifer in the area of Zayandehroud from southern part of the aquifer to its northern part is about 7356 m3/day. In contrast, when water flows in the river (i.e. river wet period), the above-mentioned groundwater flow rate has been increased to about 62384 m3/day. Therefore, the recharging rate of the river to the aquifer is about 55028 m3 /day. In other words, the recharging flow rate from the river to the aquifer in the region of the Isfahan city is about 0.64 m3/sec. Therefore, a perennial flow rate equal to 0.64 m3/sec in the Zayandehroud River can prevent hydrological imbalance and its impacts such as land subsidence, water shortage and salinization of groundwater. These results represent a strong and effective relationship between groundwater and the Zayandehroud River, which more emphasis on the role of recharging by the River to the groundwater, and wet period of the River plays a significant role on the aquifer of Isfahan city.

Surface water (SW) and groundwater (GW) are connected components of the hydrologic system with a dynamic interaction at different local or regional scales. In the first part of this study, the review of principles and general concepts of GW-SW, including the importance of interaction between these two water components is carried out. In the second part, a review of the scientific studies on the interaction of GW-SW at different spatial scales ranging from the point scale to the regional scale is presented. In each of these scales, the differences between the mechanisms of interaction with other scales are investigated and then regional modeling is specifically studied. Regional GW-SW is rarely examined in experimental field studies, which almost exclusively cover small areas. There are various modeling approaches and a few of them can be used in the regional scale but there are still uncertainties about using them. If GW-SW at the regional scale is essentially regarded as the sum of all hydrological processes in a region/catchment, then the most appropriate way to address this seems to be the use of fully coupled, physics-based models. These models attempt to acquire a holistic description of the hydrological cycle and have an ability to connect various processes over a range of spatial and temporal scales. Most authors agree that regional scale integrated modeling is constrained by data availability. Therefore, despite the attractiveness of fully complex schemes, coupling relatively simple models may still provide a suitable approach even if this means an oversimplification in the regional systems.

In the past decades, human activities changes the quality of water resources significantly so that water resources have been contaminated or to be contaminated in the future. In this way, agriculture has more contribution to reduce water quality and increase consumption of surface water than other activities. Agricultural management in river’s watershed is one of the main approaches to improve the quality of water resources. Water quality simulation models in the basin scale, are the practical tools to simulate the impacts of various activities such as agriculture on the quality and quantity of water resources. In this study, the SWAT model to simulate the salinity load under two cycles, heavy metals and nitrogen in the catchment basin Navrood who represents the West Guilan, was used. The accuracy of the model to simulate the salinity in the two methods was compared. Calibration and validation of SWAT was conducted by data series of salinity and discharge during 2006-2013. To assessment the efficiency of model, two statistical indicators R2 and NS was calculated. The values of the indicators in simulating river flow were 0.82 and 0.58 respectively. In salinity simulation, these indicators were 0.30 and -0.71 under heavy metals cycle and 0.61 and 0.54 under nitrogen cycle, respectively. Therefore, the use of the nitrogen cycle in simulation of salinity load of Navrood basin is recommended.

The impact of land use change in the water quality changes is major challenges in water supply for different expenditure. This article evaluates the land use change effects on Zayandehrood river water quality. In this study, the change of land use in two periods in 1997 and 2015 was performed by TM and ETM Landsat satellite. Then, change of water quality in the 18-year period was studied. The results showed a major decline in water quality in the river's profile with increased phosphate, nitrate, EC, BOD, COD and TDS in the study period. Pearson correlation test showed a significant correlation between agricultural land with nitrates, phosphates and electrical conductivity and between the city and electrical conductivity. Mann-Kendall test showed that the trend of the most variables is ascending. Results showed a decline in water quality as a result of land use changes on river basin to reduce rangeland, forest, water and increasing the bare lands, agricultural lands and cities. Thus, there is need to proper implementation of programs to control land use change in order to maintain ecological balance.

Plain water balance is one of the most important issues from the view of water resource management and decision-making and planning of natural resources, agriculture and environment aspects. On the other hand, a survey of the water balance due to diversity of input and output components and uncertainties in the estimation of some environmental parameters makes the calculations extremely complex. Simultaneous evaluation of ground and surface water balance due to increases of input and output components in the field and watershed scales can intensify this complexity. The purpose of this study is to introduce a comprehensive and simple water balance equation, including all parameters of ground and surface water balance. In order to be able to analyze the data and determine outputs and inputs of Tuyserkan plain water balance, the data of precipitation and runoff as well as the primary base map data were collected. Initially, ground and surface water balance components were investigated separately, and then a comprehensive and simple formula was introduced to determine the complete plain water balance. The simplicity of the proposed equation is an advantage as the water balance components have been considerably decreased, (6 input components have been decreased to 3, including incoming surface runoff, incoming subsurface flow and precipitation and 5 output components have been decreased to 3, including evapotranspiration, outgoing subsurface flow and outgoing surface runoff).The presented equation seems to be applicable for other plains.