پژوهشی
RS
Mehdi Feyzolahpour
Abstract
Extraction of the water zone in the western parts of Afghanistan through remote sensing images is an efficient way to investigate and monitor water resources and its impact on the water resources of eastern Iran, especially the wells of Sistan and Baluchestan. In this research, from OLI sensor of Landsat ...
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Extraction of the water zone in the western parts of Afghanistan through remote sensing images is an efficient way to investigate and monitor water resources and its impact on the water resources of eastern Iran, especially the wells of Sistan and Baluchestan. In this research, from OLI sensor of Landsat 8 satellite and TM sensor of Landsat 5 satellite, Normalized Difference Water Index (NDWI), modified Normalized Difference Water Index (MNDWI), normalized difference moisture index (NDMI), automated water extracted index (AWEI), new water index (NWI), and water ratio index (WRI) have been used to extract water areas. In the worst case, the area of the Arghandab dam has decreased by only 2.44 km upstream and the NDMI index has shown an increase of 0.65 square km in the moisture resources of this dam. However, the surface of the well in the southern half of Zabul has decreased from 55.94 square kilometers to 17.82 square kilometers, which shows a decrease of 38.12 square kilometers. This shows a sharp decrease in the level of the semi-well. This has caused more heat to be emitted in the dry areas. But the minimum temperature has decreased from 17.47 degrees to 11.87 degrees Celsius, which has experienced a decrease of 1.95 degrees Celsius. The LST index has a negative correlation with all the indices and the highest correlation with the NWI index was -0.941 in 1994. The lowest correlation was also obtained at the rate of -0.65 related to the NDMI index.
پژوهشی
Hydrogeomorphology
Mohammad Hossein Rezaei Moghaddam; Davoud Mokhtari; Tohid Rahimpour; Vahideh Taghizadeh Teimourloei
Abstract
Azarshahrchai catchment area, located on the western slope of the Sahand mountain range, is formed by the connection of numerous tributaries flowing in deep valleys, and every year in the spring season, with the onset of rains, floods occur in these valleys. The purpose of this research is to evaluate ...
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Azarshahrchai catchment area, located on the western slope of the Sahand mountain range, is formed by the connection of numerous tributaries flowing in deep valleys, and every year in the spring season, with the onset of rains, floods occur in these valleys. The purpose of this research is to evaluate the performance of the weighted evidence (woe) function for preparing the flood susceptibility map of the Azarshahr Chai catchment area. In order to reach the mentioned goal, first, the location of 82 flood catch points using Landsat8.c2.l2 satellite images based on the flood of April 2016 was randomly divided into two groups of 70% (57 flood catch points) for training data and 30 percent (25 points) flood) was used for validation data. Then 14 effective factors in flood occurrence elevation, slope, Aspect, slope curvature, distance to river, distance to road, river density, TWI (topographic moisture index), lithology, soil type, rainfall, and NDVI in Arc software environment and land use in ENVI5.3 software environment, analysis, and location of flood catch points in all 14 factors were investigated. The ROC operating characteristic curve was used to validate and correct the results obtained. The results of the research indicate that 19.56% of the basin is in the very high sensitivity class, 19.18% in the high sensitivity class, 24.61% in the moderate class, 21.94% in the low class and 14.68% in the shallow class in terms of flood vulnerability.
پژوهشی
Hydrogeomorphology
Sayyed Hojjat Mousavi
Abstract
Problems of watersheds and their water resources require comprehensive planning and integrated management in this natural open system, which is necessary to be prioritized in national and regional plans to achieve the sustainable development goals, flood risk and crisis management, and solving water ...
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Problems of watersheds and their water resources require comprehensive planning and integrated management in this natural open system, which is necessary to be prioritized in national and regional plans to achieve the sustainable development goals, flood risk and crisis management, and solving water shortage issues. Purpose of this research is the evaluating and analyses of hydrogeomorphometric components in Bastam watershed systematically to understand environmental, flood and erosion issues. In this regard, parameters of the height distribution, average height, altimetry and hypsometry curves, slope, aspect, watercourse rating, branching ratio, drainage density, watercourse boundary, main watercourse length, concentration time, perimeter, area, basin shape, Gravilius coefficient and equivalent rectangle was evaluated. Results showed that study basin with an average height of 2085.341 meters and an average slope of 21.788% is a mature and relatively smooth basin, and its upstream slopes at altitudes of more than 2100 meters are exposed to exploration due to the roughness youth. Maximum extent of the basin with 24.53% belongs to the southeast aspect. Shape of the basin is like a rectangle with a length of 91.842 km and a width of 19.175 km, which has a medium to small flood capacity. Components of branching ratio 3.528, drainage density 0.2985 and compression coefficient 0.09352 indicate the low to moderate flooding of this basin. Its concentration time in the main waterway with a length of 62.675 km is equal to 6.066 hours, which has the maximum flood with 6-hour rains.
پژوهشی
Hydrology
zohreh khorsandi Kouhanestani; Fatemeh Taatpour
Abstract
Rainfall-runoff processes are among the most complex and nonlinear phenomena in hydrology. In water resources management, runoff forecasting faces challenges in ungauged watersheds.In this study, the efficiency of lumped models and machine learning methods was investigated in the Kabkian watershed, that ...
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Rainfall-runoff processes are among the most complex and nonlinear phenomena in hydrology. In water resources management, runoff forecasting faces challenges in ungauged watersheds.In this study, the efficiency of lumped models and machine learning methods was investigated in the Kabkian watershed, that is one of the principal branches of the Karun River. AWBM, Sacramento, SIMHYD, TANK, and SMAR Also, some algorithms in decision trees, artificial neural networks, and support vector regression were applied to simulate daily and monthly runoff in the Kabkian watershed. Monthly and daily discharge, precipitation, and potential evapotranspiration for the period between 1972 and 2022 were used,. The accuracy and efficiency of the methods were examined using R², the Nash-Sutcliffe coefficient, and RMSE. Results showed that SMAR and AWBM, in comparison to other lumped models, have the best efficiency in the simulation of daily discharge in the Kabkian watershed. The Nash-Sutcliffe coefficients for them in the test stage are 0.79 and 0.78, respectively, showing that these models have good efficiency in daily discharge simulation. Also, the SMAR and AWBM models' Nash-Sutcliffe coefficients are 0.71 and 0.72, respectively, and the R2 for the two models is 0.79 in the monthly time series. These values show that these models have good efficiency. In machine learning methods, in the daily series, the random forest algorithm's R2 is 0.61 and has the best efficiency in comparison to other methods. Also, in the monthly series, the random forest's R2 is 0.93, which illustrates good discharge simulation efficiency.
پژوهشی
Hydrology
Leyla Babaie; Hirad Abghari; Raoof Mostafazadeh
Abstract
The occurrence of low flow and high flow periods in watersheds is a part of a river's regime. In recent years, changes in river flow and its intensification have impacted the production and utilization of river flows as well as water management, making it an important area of study. Evaluating various ...
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The occurrence of low flow and high flow periods in watersheds is a part of a river's regime. In recent years, changes in river flow and its intensification have impacted the production and utilization of river flows as well as water management, making it an important area of study. Evaluating various characteristics of the flow regime of natural rivers can help understand how river discharge changes due to climatic. In this study, changes in high flow and low flow indices at the Bitas watershed, Mahabad-chai, which monitors a naturally flowing river upstream of Mahabad Dam, were assessed for the period from 1963 to 2020. The results indicated that the Number Spell index was 144 during high flow periods and 253 during low flow periods. The Single Longest index was 1,635 for low flow periods and 163 for high flow periods. The average peak flow and average duration of peak flow indices for high flow periods were 22.6, and for low flow periods, they were 0.33. Additionally, the mean duration was 29.6 for high flow and 54.82 for low flow. According to the results, the total duration index for high flow periods fluctuated between 3 and 163, while the total duration index for low flow was 241. The findings of this study can be used to better understand changes in the natural flow regime, variations in the timing and frequency of low and high flow events, and ultimately to optimize the management of inflow to Mahabad Dam.
پژوهشی
watershed
Mahnaz Saber; Bromand Salahi; Roghayeh Maleki Meresht
Abstract
The SWAT model was used in this research to simulate the hydrological conditions of the Aras River basin in the future period. The model was calibrated based on the data of 1987-2006 and its validation was done in 2007-2014 with the SUFI2 algorithm and the SWAT model was calibrated based on the monthly ...
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The SWAT model was used in this research to simulate the hydrological conditions of the Aras River basin in the future period. The model was calibrated based on the data of 1987-2006 and its validation was done in 2007-2014 with the SUFI2 algorithm and the SWAT model was calibrated based on the monthly flow rate of the selected hydrometric station. After selecting the optimal parameters and running the simulation in 350 simulator rounds, the values of the evaluation criteria were obtained in the calibration period and in the validation phase. To evaluate the water balance changes of the basin under the conditions of climate change from the downscaled data of the CNRM-CM6 climate model in the historical period (1985-2014) and the future period (2025-2100) under the SSP5-8.5 scenario were used as input data to the SWAT model. The findings showed that evapotranspiration of the Aras basin has wasted a large share of the precipitation of 272mm in the historical period and 351 mm in the future period of the basin, and the amount of infiltration and lateral flow, which are necessary to feeding underground and surface resources, is very low. Also in terms of land use, the minimum ET of the basin was calculated in the use of good pastures. Also, the findings showed that although in the future period the annual rainfall will be 79 mm more than the historical period, but a major part of it will be spent on evapotranspiration in the months of May to July.
پژوهشی
watershed
Ali Parvish; Hirad Abghari
Abstract
Watershed management, regardless of the role of local and state operators, will derail water and soil conservation policies and have many negative impacts and consequences in the long term. One of the water supply sources of Lake Urmia is the Baranduzchay River basin. Due to the increasing consumption ...
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Watershed management, regardless of the role of local and state operators, will derail water and soil conservation policies and have many negative impacts and consequences in the long term. One of the water supply sources of Lake Urmia is the Baranduzchay River basin. Due to the increasing consumption behavior of the population, sand mining and exploitation of this river is increasing day by day. Due to the need and importance of flood management and flood control to prevent social and economic problems, this research was carried out with the aim of studying the effects of non-standard sand mining on the hydraulic discharge of the river. The study area is located in the Baranduzchay River in West Azerbaijan Province, Urmia County. In this research, a section of the river from the geographic coordinates 490675 UTM and 4121955 UTM (upstream) to the geographic coordinates 490995 UTM and 4125550 UTM (downstream) is examined. In this research, topographic information is used before harvesting the riverbed and riverbank materials and the triangular irregular network (TIN) is extracted to verify the elevation features using the HEC-GeoRAS plugin, which is a bridge between the hydraulic model of HEC- RAS and ArcGIS: The effects of excessive sand mining on the hydraulic and hydrological properties of the river were studied. According to the research objective, the effects of extracting 1 to 2 meters of hydraulic runoff were simulated. This research showed that when the depth of the river bed increases by one to two meters, the cross section
پژوهشی
Hydrology
Raoof Mostafazadeh; Javanshir Azizi Mobaser; Shahnaz Mirzaei
Abstract
The river flow regime can be influenced by various climatic and anthropogenic factors, including land use changes, dam construction, flow diversion, and water abstraction, leading to changes in available water and environmental flow allocation patterns. This study compares the changes in flow regime ...
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The river flow regime can be influenced by various climatic and anthropogenic factors, including land use changes, dam construction, flow diversion, and water abstraction, leading to changes in available water and environmental flow allocation patterns. This study compares the changes in flow regime components between two rivers, one natural and one regulated by a dam, in Ardabil Province. Using R programming, various charts, change point analysis, and significant temporal trends were derived for flow statistics, including high flow, low flow, and baseflow. The results indicate change points in all three flow components (annual maximum, Q10, Q25, low flow, and baseflow) in both natural and regulated rivers, with more pronounced changes occurring in the regulated river after dam construction. In the natural Khiavchai River, high flow and peak discharge showed no significant trends, whereas in the regulated Balikhlochai River, all flow components exhibited significant decreasing trends. Comparison of flow duration curves and violin plots revealed substantial reductions in minimum flows and baseflows in the regulated river, with monthly discharge distributions strongly influenced by dam regulation. Comprehensive evaluation of river regime changes and flow components enables prediction of trends and effective water management for environmental flow allocation.
