IRANIAN JOURNAL OF ECOHYDROLOGY
Year:2019 | Volume:6 | Issue:1 |Papers Count:20

The construction of multiple structures disconnects the migration course of fish in the river. Fishways are the most effective solution to re-establish the longitudinal connectivity of the river. Nature-Like fishways are among of the structures constructed in the last two decades and now that the point of views of river engineers in the world have changed and they seek to rehabilitate the rivers, it is necessary that our country's engineers also seek to design Eco-friendly structures, such as nature-like fishways. The purpose of this research is to present the basics of nature-like fishways and to design it for one of Iranian river and to evaluate it with the mathematical model of PHABSIM. The bypass is planned using stone weirs with hydraulic loss of 0. 25 meters with pools of width 4 and 5 meters in length, and a volumetric dissipated energy of 98. 1 watts per cubic meter, and riffles with a width of 2 meters wide in design were considered. By using the PHABSIM mathematical model, the habitat suitability of the designed bypass channel was investigated and it was observed the fish in the riffles, unlike the pools, the channel sides were chose as a suitable habitat for more suitable speeds.

In the present study, nonlinear characteristics of the monthly flow of Zayandehrud River in both pre and post noise reduction were evaluated using chaos theory during 43 years (1971-2013) in four hydrometric stations. To determine the chaotic or randomness of the Zayandehrud River flow, the phase space was first reconstructed. Therefore, the optimal delay time and embedding dimension are calculated using the average mutual information and the nearest false neighbors. The possibility of chaos in the monthly flow, in the original and denoised time series, has been investigated using the correlation dimension. Based on the results, the correlation dimension for the denoised time series at Eskandari, Ghale Shahrokh, Pole Zaman Khan and Pole Koleh stations is estimated to be 5. 94, 4. 63, 2. 89 and 3. 30, respectively. The non-integer value of this dimension shows the chaotic behavior of monthly flow of the Zayandehrud River at these stations. The absence of correlation dimension in the original time series indicates the randomness of the system. Sensitivity to the initial conditions of the system, as a characteristic of chaotic systems, was investigated using the Liapunov exponent. Thereafter, the horizons of forecasting the current flow at the denoised stations were determined to be 36, 41, 45 and 44 months, respectively. One of the strategies for managing water scarcity and water crisis is to predict surface water discharge. By using the simulated monthly data of Zayandehrud River, it is possible to predict the flow by applying different methods, which was not possible for the original time series.

The purpose of this study is to assess land use change impacts on quality of surface water resources in sub-basins of Hableh rood watershed. In order to fulfill this task, and by using Principal Component Analysis (PCA) and Factor Analysis (FA), TDS was selected as an indicator of water quality parameter. In the next step, by time series models (ARIMA), TDS was modeled for 30 years and among different ARIMA models, a model with a lowest error and akaike (AIC) criterion was selected as an optimal model for TDS. Desirable models for Benkuh, Delichay, Gursefid, Keylan, Namrud, Marzdaran and Tangeh Rameh were (0, 1, 2), (0, 0, 1), (1, 1, 2), (4, 1, 0), (0, 1, 1), (1, 1, 1) and (1, 1, 1), respectively. The results of time series models (ARIMA) showed that Namrud, Keylan and Gursefid have maximum amount of TDS. Then, land use was studied that showed maximum area of agricultural lands, residential and roads in these sub-basins. On the other hand, Industrial areas are located in Keylan and Namrud. The results of this study showed efficiency of time series modeling andmultivariate statistics in the analysis of land use change impacts on water quality parameters.

It is highly important to identify vulnerable areas and protect groundwater resources in the Gharesoo-GorganRood coastal aquifer due to the overexploitation of groundwater resources in this area. Therefore, in this study, the GALDIT model and Entropy method in GIS environment was used to evaluate the vulnerability of coastal aquifer. The parameters of the type of aquifer, the aquifer hydraulic conductivity, the height of groundwater above the sea level, distance from shoreline, the qualitative impact of seawater intrusion, and thickness of aquifer were used in the GALDIT model, which influence the assessment of coastal aquifer vulnerability. The maps were arranged in the form of six information layers using ArcGIS software. To more accurately assess the vulnerability, the weights of GALDIT parameters were modified using the entropy method, and GALDIT-Entropy vulnerability map was obtained. The correlation coefficient between the TDS parameter and vulnerability indices in the study area was used to obtain the optimal model. The correlation coefficient between GALDIT-Entropy model and TDS parameter was obtained 0. 51, while the amount of this coefficient was 0. 43 for GALDIT model. According to GALDIT-Entropy model, the northwest, southwest and west areas of aquifer have higher vulnerability to seawater intrusion. The map of this model is classified into four vulnerability classes of low, moderate, high, and very high which compose 14, 33, 30, and 23% of the study area, respectively. The GALDIT-Entropy model reduced the errors from expert opinions in the initial GALDIT. The proposed method can be used to assess vulnerability in the coastal aquifers with the same hydro-geological conditions.

The decline of water table is very important in from a managerial point of view and might cause negative impacts such as land subsidence, raising costs and reducing groundwater quality. Groundwater is the most important source of water supply in Dehgolan plain. Increasing water requirements and extractions, has declined water table. This plain with an area of about 780 km2 is one of the protected plains of the Kurdistan province and with decrease in water table about 37 meters, it has the most decline between the plains of the province. The purpose of this study is to model the groundwater level and compare the performance of the method of Adaptive Neuro-Fuzzy Inference System (ANFIS) with Inverse Distance Weighted (IDW), Kriging and Cokriging methods. For this purpose, in September 2016, the water table data relating to the 44 Piezometer digged in Dehgolan plain has been used for modeling. The results show that the hydraulic head behavior is different across the aquifer, so the use of spatial data (h) for modeling doesn’ t lead to satisfactory outputs. The water table in Dehgolan plain has the highest correlation with topography conditions and the ANFIS with a RMSE = 0. 07, MSE = 0. 005, MAE = 0. 06, MBE = 0. 04 and = 0. 88 R2, has presented better performance than other methods.

One of the suitable strategies for run-off management in watershed areas is correct use of land according to its capability. A watershed manager could offer optimal land use between different combinations of land uses according to capability and limitations which exist in watershed. The purpose of this study is land suitability classification using Fuzzy-AHP method in the Kardeh dam watershed of Mashhad and its effects on run-off quantity using SWAT model. For this purpose, the present land use map of the study area was prepared using remote sensing and field surveys. The SWAT model was calibrated and evaluated using current land use map. Then, criteria and constraints were determined for rangeland, agriculture, forest, and urban land use. Land suitability map for the mentioned land uses was prepared using combination of Fuzzy and AHP methods by MCE in EDRISI software. The prepared land suitability map introduced into the SWAT model instead of the existing land use map and results were evaluated. Results showed that 13. 98 percent of the watershed area is suitable for forest and the area of rangelands has decreased in land suitability map. The results of the SWAT model showed with optimal land use in Karde dam watershed, mean and maximum of daily discharge have been reduced respectively 16. 25 and 4 percentages. Reduction of the discharge amount helps in flood declining and recharge of groundwater.

Shabestar plain is an active agricultural area and the utilization of groundwater resources is extremely important due to the shortage of surfaces water resources. Increasing of population and technological and agricultural activities possibly causes the aquifer contamination in this area. Therefore, assessing the groundwater vulnerability of this aquifer will be very useful for development, management and land use decisions, to monitoring of the groundwater resources quality and preventing the contaminations of groundwater resources. In this study DRASTIC and SINTACS methods were used to assess the vulnerability of the Shabestan plain aquifer. Considering that the ratings and weights of the DRASTIC and SINTACS models are somewhat expertly Wilcoxon rank-sum test (WRST) method was used to improve the ratings in both the models and in order to optimize weights, simple statistical (SS) and genetic algorithm(GA) methods were used. Finally, the optimized WRST-SS-DRASTIC, WRST-GA-DRASTIC, WRST-SS-SINTACS, WRST-GA-SINTACS models were made. In all optimization models, the determination coefficient between the nitrate concentration and the vulnerability index was increased relative to the original model. The higher determination coefficient of the WRST-GA-SINTACS model than other optimized models represents the better performance of this optimized model in the study area.

Snow avalanche is one of the phenomena in snowy and mountainous areas that may result in hazards and irreparable problems. The objective of this study is to determine the most important effective factors in avalanche events in Meigoun-Shemshak road. Meigoun-Shemshak road has been located in Shemshak drainage basin with an area of 37. 75 Km2 in Roodbar Ghasran district, Shemiranat County, Northeast Tehran. To assess avalanche corridors, effective environmental parameters on avalanche including length of valley, width of valley, azimuth, slope percentage, valley curvature coefficient, elevation, clay, silt, sand, roughness coefficient, vegetation and rock cover percentage, precipitation, temperature and snow were determined. In the studied area, three types of valley were identified: ephemeral avalanche valley, permanent avalanche valley, without avalanche valley. The environmental parameters comparison between ephemeral avalanche valley and permanent avalanche valley showed that slope percentage, roughness coefficient, clay, silt, sand, vegetation and rock cover percentage are significant in the valleys and also in comparison between the sections of them only valley curvature coefficient was significant. In comparison between three types of valleys, parameters: Azimuth, valley curvature coefficient, slope percentage, surface roughness, vegetation and rock cover percentage were significant. The results of comparison between sections of the three types showed valley curvature coefficient was the significant parameter. The most important parameters affecting the avalanche are Azimuth and surface roughness coefficient.

The climate of the land has always been changing over time but the current trend in climate change has become important due to the role of humans which has been unprecedented over the past years. In this study, The LARS WG and SDSM models are used to evaluate the climate change at Bojnourd station for downscaling climate and both models evaluate A and B scenarios but also used RCP new scenario in SDSM. The result of the status of the station showed temperature mean station is 13. 52 c but after 2000, the temperature of the station is higher than its long-term average. The results of the LARS WG model show that precipitation will increase at the station in year 2050. In scenario B1, the amount of precipitation increase almost 16 mm more than base precipitation to 2050 and all season’ s precipitation are increasing in this scenario. In scenario A2, the increase in this scenario reaches almost 256mm. In total, the SDSM model downloading to increase precipitation and this increase showed A1 and B2 scenarios more than RCP scenarios, therefore In the scenario A2 value is 289mm, the scenario B2 is 294 mm, the scenario RCP 2. 6 is 264 mm, the scenario 4. 5 RCP this is 273 mm and in the RCP scenario of 264 mm. In the case of temperature in the LARS WG model, the minimum temperature increases in both cases. The maximum winter temperature rise is 0. 8 c in the A2 scenario. In both scenarios, the maximum temperature in March, April and May is the highest increase compared to other months. The SDSM model shows that the maximum and minimum annual temperatures of this model are lower temperatures than the base period. But the monthly increase in the months of March, April and May is the minimum and maximum increase, which indicates the matching of the results of both models.

Underground water is one of the most important natural resources for societies, agricultural and industrial activities. One of the most important sources of Karst is its water resources. Understanding the factors influencing feeding springs can help us manage water resources and also, determine areas with high potential of Karst water resources. The purpose of this study is to determine the Karst water resources potential of the Parao-Bisetoun karstic mass. Hydro-chemical analysis of water was used to understand the origin of Karstic springs in the study area. Carbonate type, calcific facies, position in the left region of the Piper diagram and study of molar ratio, all indicate the Karstic source of springs in the study area. In this study, action is taken to determine the potential of underground water resources in the Parao-Bisetoun karstic mass, using the TOPSIS model and the study of 8 variables of lithology, fault density, rainfall, drainage density, slope, elevation, slope and vegetation. For this purpose, fuzzy logic is used to standardize the layers and used Analytic Hierarchy Process (AHP) to determine the weight of each layers. Eventually, with the implementation of the model, the map of Karst water resources potential of the study area was obtained. The review of the final map indicates the great impact of the two lithological factors and faults on the potential of Karst water resources, so that classes with high potential matches on the thick formations of the limestone layer with high density of faults and local fractures. As far as lithology is concerned, the class with a lot of potential matches with Bisetoun lime unit, having the purest type of lime, plus parts of radiolarities. In general, high water springs such as Sarableh, Bisetoun, Barnaj, Shah Hussain and Varmanjeh lie in the margin of many potential and very high classes. This illustrates the proper estimation of the model from high potential of Karst water resources.

One of the main variables in calculating the water balance and land surface energy is Actual evapotranspiration. Different methods for calculating actual evapotranspiration have been presented so far. Investigate and compare various existing methods for estimating actual evapotranspiration in the Urmia Lake basin in order to select an optimal algorithm was The purpose of this study. Using the ETLook, SEBAL, SEBS and S-SEBI algorithms based on the energy balance equation, the results obtained by comparing the results of different algorithms showed that the ETLook method has been able to utilize the latest methods of estimation of evapotranspiration. Many The weaknesses of other algorithms are covered. This two-source method analyzes vegetation and soil separately, by using soil moisture images, has not even been able to withstand its efficiency in calculating evapotranspiration, even in cloudy days. However, the commercialization of this algorithm and the great difference in the results of the global WaPOR product (produced with ETLook) with ground observations in the Urmia Lake basin has made it less and less convenient to use. Considering all the conditions, including having a suitable physical base, ease of implementation and comparison with ground values, it can be admitted that the SEBAL algorithm is the most suitable option for estimating the actual evapotranspiration of the Urmia Lake basin.

Uncertainty analysis is an inseparable step in the process of hydrological modeling. Quantitative assessment of the uncertainty in the simulation model outputs and its parameters lead to an increase of confidence in the results of modeling and understanding of the sources of uncertainty. Due to the increasing use of groundwater management model and predicting the behavior of the aquifer, this research is seeking to analyze the uncertainty in quantitative-qualitative aquifer simulation and its effect on optimization results. Using SWAT hydrologic model, the amount of recharge is specified and inserted into MODFLOW groundwater flow model and MT3DMS transmission model. In this research, the DREAM (zs) algorithm (based on Monte Carlo Markov chain algorithms) was used to examine the uncertainty of MODFLOW model parameters. Then by linking the model with MOPSO, the optimum head and salinity are obtained in the aquifer. The results show that the accuracy of the inputs of the model leads to the desirability of the results in relation to the intended purpose of reducing the water table.

Soil erosion is a serious environmental, social and economic problem. It not only causes severe land degradation and soil loss, but also threatens the stability and health of the society and, in general, its sustainable development. Soil erosion is related to different soil characteristics, measurements and its calculations. The soil erodibility factor (K) is one of the important factors in determining soil erosion. Different methods have been developed to determine of K using empirical models or field measurements. Currently, widely used equations that estimate K, on the basis of soil basic properties, include soil texture, organic matter, structure, and permeability. Therefore, in this study, three commonly equations were used to estimate of K in Shazand watershed such as Wischmeier and Smith (1978), Romkens et al. (1986), Torri et al. (1997 and 2002) with K1, K2 and K3, respectively. In this regard, field sampling was done at 140 points of Shazand watershed with an area of 1740 km2. The Shazand watershed has limestone with low organic matter and medium texture. In the following, one-way ANOVA was used to analyze of K1, K2 and K3 results under the impact of different slope and elevation classes and different land uses, as well as Kriging's method for generation their spatial pattern. The results of one-way ANOVA showed that K1, K2 and K3 influenced by different slope and elevation classes with a significant difference (P< 0. 05). But they had no significant difference (P ≤ 0. 318) in different land use. Also, the average of K1, K2 and K3 was calculated to be 0. 054, 0. 039 and 0. 035 t ha h ha-1 MJ-1 mm-1 respectively.

The aim of this study is to determine the most important geomorphometric indices and structural features affecting Submarine Groundwater Discharge (SGD) into the Persian Gulf coastlines. For this purpose, firstly, the maps of lithology, density of lineament, zoning rainfall and temperature, vegetation cover index (NDVI), drainage density, slope, elevation classes, abundance and distribution of springs, profile, length, cross section, general, plate, tangent, total curvatures, and surface ratio, topographic roughness, Vector Ruggedness Measure, Topographic Position, and Topographic Wetness, were prepared on three radii of 10 (buffer 1), 20 (buffer 2) and 30 (buffer 3) km from the coast to the land, using ENVI 5. 3, Arc GIS10. 3. 1, and SAGA GIS 2. 1. 0 software. Then, the most important factors and the contribution of them in presence the SGD areas were determined using multivariate regression analysis. The results showed that the plate and profile curvatures are the most important curvatures with opposite scores and values. Indicators affecting the presence of SGD areas for the cold season are: springs abundance on buffers 2 and 3, topographic wetness on buffer 3, drainage density on buffer 1 and 3, fault density on buffer 2 and aquifer surface on buffer 1, and for the warm season are: springs abundance on buffer 2 and 3, topographic wetness on buffer 1, cross section curve on buffer 2, total curvature on buffer 2, temperature index on Buffer 3, fault density on Buffer 3, and aquifer surface on buffer 1. In overall, the SGD mapping can be created by integration of several maps including springs abundance, topographic wetness, cross section curve, total curvature, temperature index, fault density, and aquifer surface.

In recent years, increasing salinity and reduction in the quality of groundwater have become one of the environmental challenges due to the penetration and mixing of pollutants. These challenges have created serious risks for the development of human societies and health. In order to prevent future risks and appropriate planning for preserving water resources, a qualitative study of groundwater resources is an essential requirement. In this research, a swarm intelligence approach based on election algorithm and gray wolf optimization algorithm is presented to determine the optimal values ​ ​ for water quality parameters such as TDS, EC and SAR. In order to evaluate the proposed method, data on the plain of Bostanabad city in the 10 years period (2003-2013) were used and the results were evaluated based on Wilcox, Schuler and Piper measures. The results of the experiments show that the underground water of Bostanabad city is modest to acceptable for agriculture and drinking and is suitable for industry due to corrosion and hardness. Most of the data were in the C2S2 class, which is suitable for agriculture. The correlation coefficient above 95% indicates the acceptable accuracy of the gray wolf optimization algorithm in comparison with the election algorithm in estimating the groundwater quality parameters.

Hyporheic zone is related to the saturated zone beneath the river which has an important role in ecology. In this zone, part of surface water, transfer oxygen and nutrients to the organism and then returns to the surface water after certain amount of time. Hyporheic exchanges between surface flow and flow in porous media can be created due to the different bed forms of river. Riffle-pools are topographical features found in straight, meander and braided rivers. Variation of pressure along these bed forms lead hyporheic exchanges. The precise estimation of hyporheic exchanges and residence time can be useful for rivers restoration projects. So, in this paper, in addition to laboratory investigation of hyporheic exchanges along riffle-pool bed forms, the variation of pressure along bed surface has been simulated numerically by Large Eddy Simulation (LES) model and then a groundwater model and particle tracking method have been applied to simulate the flow within the hyporheic zone. The results show that the interFoam solver with LES model is able to model laboratory conditions accurately. The mean percentage error of water surface profile was 1. 8% for present laboratory study, which leads to an accurate estimation of pressure along the bed form and as a result an accurate prediction of hyporheic exchanges. The results of hyporheic characteristics show that as Reynolds number increases, the hyporheic exchanges increase and the residence time decreases. The results also show that the residence time distribution follows generalized extreme value distribution. In this study, on average, 20 percent of surface flow exchange with sub-surface flow.

Environmental flow science is a current tool for assessing the outcome of changing the flow regime of aquatic ecosystems and providing a minimum flow of protection aquatic species. The purpose of this research is to provide the essentials in preparing the tools for the assessment and design of restoration and regeneration projects for Zarrin-Gol river habitats using ecohydraulic and hydromorphological indices based on the habitat suitability simulation. In this regard based on the research framework, after the field studies and the development of the habitat suitability model for the target species, the hydrodynamic simulation of the flow was carried out and eventually the ecological flow regime was extracted. The results showed that River2D model by connecting the flow requirement characteristics of C. Capoeta gracilis and using hydraulic and hydrological relations, would have the maximum and minimum flow regime required to maintain the Zarrin-Gol river ecosystem according to ecological needs in the months of April and October is estimated to order equivalent to 5. 09 and 0. 89 m3/s, with average 1. 79 m3/s (equivalent 84 percent of natural stream of the river). Based on the results of this study, in environmental studies of water resources and river engineering, the two-dimensional hydrodynamic River2D model is able to simulate flow, modeling habitat suitability of target species and predict the dynamics of habitats to protect the proper habitat of fish in river ecosystems. The calculation of the environmental flow can be an appropriate estimate for the ecological response of the river to the morphological changes caused by hydrological and hydrological processes.

In this research, based on the status of groundwater level in the region during the statistical period of 30 years (1365-1395), as well as field studies and drilling three borehole, study of the status of sediments in place and the chemical analysis of samples taken from the boreholes, the status of subsidence and Penetration of salt water in Minab Plain has been studied. The study of the status of groundwater level in the area indicates that the water level drop in this aquifer has intensified since 1380, and it has fallen an average of about 46 centimeters in a year. The drop in water level in the aquifer has caused the aquifer level to be lower than the sea level, and practically water flows from the sea to the aquifer. Geotechnical studies in the area show that in addition to the drop of water surface, presence of inflammable and soluble sediments in the area has increased the severity of subsidence complications in the plain surface. Finally, the area is classified into three general sections in terms of risk of subsidence. In the primary part of the aquifer, subsidence is often in the type of alluvial layers condensed, in the central part, the subsidence is often in the form of a pit and a crack, and in the end section of aquifer probability of subsidence is low. In general, this aquifer is at the same time faced with the phenomenon of subsidence and the advent of salt water and requires proper planning to prevent the destruction of the aquifer.

In this study, for the first time, the capture zone is determined and depicted in two confined and unconfined aquifers using a numerical method. The engaged numerical method is meshless local Petrov-Galerkin which is not used in this field and in this application. The confined aquifer has regular geometry with 4 extraction wells. After simulating the groundwater flow, capture zones of wells is depicted in 1-month, 1-year, 2-year and 5-year time periods. Then the effect of both hydraulic conductivity and storage coefficients is evaluated in order to see the changes in shape and development of capture zone. The results indicated that by passing the time the area and width of the capture zone get greater, in other words, when number-1 well is in extraction by itself, in the second year the width of the capture zone is 2. 82m and in the fifth year, it is 5. 8m. Also with increasing hydraulic conductivity and storage coefficients, the area and width of capture zone get smaller on the other hand the number of nodes which is located in capture zones is reduced. In another example, a capture zone depicted for a real aquifer. Birjand aquifer which is located in South Khorasan province has an unconfined type. Head is simulated and the results are compared with observation data. The RMSE errors for steady and unsteady condition are 0. 483 and 0. 757 respectively. This aquifer has 190 extraction wells. Two wells are chosen as a sample. Then capture zone for these wells is determined and depicted. The results show that extension of this region in a real aquifer is more influenced by hydraulic conductivity coefficient.

This paper aims to develop a profound framework that opts for the most techno-economic cooling system considering different climate zones of Iran, water and energy carrier prices, and the crop’ s cultivation conditions. Furthermore, it enables policy makers to come up with a water price to persuade the farmer to choose the least water consuming cooling system for the greenhouse. Three different cooling systems of fan and pad, direct expansion and absorption chiller are evaluated for five various climate zones of Iran. The evaluation takes place in three scenarios in which the first and second scenarios assesses all three cooling systems under the current and real price of water, while the third scenario obtains the optimal price of water that the cooling system get selected based on the least water consumption. Results show that the fan and pad cooling system, formerly believed to be the most economic one, is actually not the most techno-economic system for all climate zones of Iran but, the direct expansion system with the mean equivalent cooling cost of 0. 0427 and 0. 2733 $/kWh merits over the fan and pad system with the mean equivalent cooling cost of 0. 051 and 0. 8264 $/kWh in first and second scenario respectively. Finally, the third scenario suggests the policy makers should increase the water price by 17. 4% so that the farmer is persuaded to select the most water conservative cooling system in all the climate zones of Iran.