Hydrology
Raoof Mostafazadeh; Mostafa Zabihi Silabi; Mohamad Kazemi
Abstract
The increasing human needs and changes in climate patterns have led to the construction of water storage structures to meet the water demand in many regions worldwide, including Iran. Consequently, the hydrological regimes of rivers in various parts of Iran, due to human activities such as dam construction, ...
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The increasing human needs and changes in climate patterns have led to the construction of water storage structures to meet the water demand in many regions worldwide, including Iran. Consequently, the hydrological regimes of rivers in various parts of Iran, due to human activities such as dam construction, have undergone alterations in recent decades. Understanding the effects of dams on river hydrological regimes is essential for river flow management and the preservation of river ecosystems. In this regard, the present study assesses the changes in the health of the Urmia's Shahrchai River flow during three periods: pre-dam construction, dam construction, and dam operation, from 1951 to 2017, through calculating different flow health related indices. The results indicate that the deviation of all hydrological health sub-indices in the post-dam construction period is higher than the pre-dam construction period. Moreover, the deviation of flow regime sub-indicators was predominantly low to moderate until 1998 and varied from low to very high after 1998. Additionally, the highest deviation of studied flow health-related indices occurred during the reference and dam operation periods for flood occurrence and minimum monthly flow, respectively, while during the dam construction period, it pertained to minimum monthly flow. Furthermore, the findings suggest that the hydrologic health of Shahrchai River flow decreased by approximately 16% and 45% during the dam construction/operation periods, respectively, compared to the reference period. The results of this study can be utilized in the understanding of flow alteration and the sustainable regulation of the Shahrchai River flow regime.
Geomorphology
Raoof Mostafazadeh; Fariba Esfandyari Darabad; Ahmad Naseri; Ahmad Abyat; Maryam Adhami
Abstract
Fractal dimension is a powerful and important index that reflects the physical and morphological characteristics of rivers and has a close relationship with geometric features of rivers. The fractal pattern was used to investigate the sinuosity of the Gharehsou River in Ardabil Province, using the box-counting ...
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Fractal dimension is a powerful and important index that reflects the physical and morphological characteristics of rivers and has a close relationship with geometric features of rivers. The fractal pattern was used to investigate the sinuosity of the Gharehsou River in Ardabil Province, using the box-counting method. The results show that the fractal dimension of the Gharehsou River varies between 2.068 and 2.186. The minimum fractal dimension is in the first category of meanders with lower areas of tangent circle, and the maximum number of circles falls into the eighth category (having high areas of tangent circle). Based on the correlation between the number and area of tangent circles (0.71 to 0.84), it can be said that the river reaches studied follow a fractal and self-similar pattern. The fractal dimension values in the Anzab village-Taleb Qeshlaqi village reach were calculated to be 2.23, indicating a higher level of self-similarity, which is related with the naturalness of this river reach, which is located within a plain area, and the river has undergone more evolution. On the other hand, in the Taleb Qeshlaqi village-Sabalān Dam reach, the fractal dimension value was found to be 1.85, which may be related to the river traversing steeper paths, limiting its meander development and making the fractal pattern less observable. Human interventions in the river's course, as well as the river's passage through agricultural lands in some cases, have led to changes in the width and depth of the river and restrictions on meander expansion.
Geomorphology
Amirhosein Ghorbani; Raoof Mostafazadeh; Mohsen Zabihi; Masoud Jafari Roodsari
Abstract
Landslide, as an important natural hazards, causes damage to infrastructure and leads to economic, social and human losses. In this regard, determining the critical zones of landslides occurrence can be used in planning for damage reduction. The aim of the current research is analyzing and identifying ...
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Landslide, as an important natural hazards, causes damage to infrastructure and leads to economic, social and human losses. In this regard, determining the critical zones of landslides occurrence can be used in planning for damage reduction. The aim of the current research is analyzing and identifying landslide hot spots using Getis-Ord algorithm in Gharnaveh watershed, Golestan province. Therefore, the frequency and characteristics of landslides has been analyzed in different classes of slope, aspect, soil and land uses. The area, length, width, depth and height of the precipice of landslide features have been considered as the basis in hot spot analysis. The results showed that the landslide hot spots are located in the eastern part of the study area, which includes high altitude classes, rangelands and moderate slopes. Results showed that the rangeland and forest land uses, loess soils and 50-75% slope class and the northern aspect had the highest number of landslides. Also, the non-significant landslide points using the Getis-Ord method and considering landslide area criterion located in the middle and downstream of Gharnaveh watershed. Determining the landslide hotspots and affecting factors through the spatial analysis in GIS provides the defining thresholds in the landslide’s occurrence. The analysis of the landslide hotspots can be a basis for spatial planning, and risk reduction. The implemented approach can be used in the evaluation of the spatial autocorrelation of natural hazards, and in combination with the areas prone to multiple environmental hazards can predict the risk and severity of damages in the future.
Zahra Sharifi; Raoof Mostafazadeh; Abazar Esmali Ouri; Zeinab Hazbavi; Mohammad Golshan
Abstract
Daily flow data are a prerequisite for water resources management, but it is not possible to measure it in many upstream watersheds. In this study, different optimization algorithms have been used to evaluate the efficiency of the SIMHYD model. Therefore, the discharge data of Kouzetopraghi rive gauge ...
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Daily flow data are a prerequisite for water resources management, but it is not possible to measure it in many upstream watersheds. In this study, different optimization algorithms have been used to evaluate the efficiency of the SIMHYD model. Therefore, the discharge data of Kouzetopraghi rive gauge station was selected as the study data (805 km2) located in Ardabil province. The daily data of rainfall, evapotranspiration of the meteorological stations in the study area were used to simulate the daily river flow data. Optimization methods including genetic algorithm, comprehensive competitive evolution, search pattern, multi-start search pattern, uniform random sampling, Rosenbrook, multi-start Rosenbrook optimization were evaluated based on statistical efficiency criteria. The mean value of discharge values by genetic algorithms, multi-year pattern search, uniform random sampling, multi-start Rosenbark, Rosenbork, comprehensive competitive evolution, search pattern were 0.031, 0.023, 0.085, 0.032, 0.024, 0.032, 0.031, respectively. The results showed that the change of optimization algorithms has a significant effect on the calibration accuracy of the model, so that the values of the Nash-Sutcliffe efficiency criteria for the employed algorithms were 0.42, 0.31, -8.55, 0.38, 0.56, 0.023, and 0.24, respectively. The Rosenbrook algorithm had higher accuracy in calibrating the SIMHYD hydrological model compared to other algorithms used. A part of the modeling error can be related to the inconsistency of precipitation and runoff data due to the multiplicity of stations.
Nahideh Parchami; Raoof Mostafazadeh; Abazar Esmali Ouri; Rasol Imani
Abstract
During the occurrence of hydrological drought, the river flow will be reduced and the quality of the river ecosystem will be degraded. Determining the temporal and spatial variations of the hydrological drought makes it possible to plan for the optimal use of river water. In this study, temporal and ...
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During the occurrence of hydrological drought, the river flow will be reduced and the quality of the river ecosystem will be degraded. Determining the temporal and spatial variations of the hydrological drought makes it possible to plan for the optimal use of river water. In this study, temporal and spatial changes of river flow index (SDI) in watersheds of Ardabil province were evaluated. In this regard, daily flow time series of 28 hydrometric stations in Ardabil province were analysed. River flow drought index was calculated using DrinC software and then hydrological drought characteristics were analyzed and spatial variations of SDI index were determined in 1-month, 3-month, 6-month and annual temporal scales in GIS software. 1-month SDI values (short-term droughts) showed that severe droughts were more common in rivers with low discharge values. However, most rivers with low and high amounts of river flow discharge have experienced severe seasons. The annual (long-term) hydrological drought index in most stations was in the range of -1.5 SDI greater than or equal to -1, which indicates the occurrence of mild drought. Spatial changes of SDI showed that the spatial variations of drought index on a 1-month scale are completely different from the annual scale. The lowest occurrence of hydrological drought was in upstream stations and flowing rivers in Sabalan hillsides. Severe and very severe droughts occur in low discharge rivers. The higher the river discharge, the lower the incidence of severe droughts, and the greater its flow stability than low-discharge rivers.
hydrogeology
Fariba Esfandyari Darabad; Zeinab Pourganji; Raoof Mostafazadeh; Maryam Aghaie
Abstract
Floods as destructive natural hazards need to be predicted in accurate way through evaluation of the hydrological response of watersheds to the effective input rainfall. Due to the variety of rainfall-runoff models, it is very important to choose a suitable model that can simulate the hydrological behavior ...
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Floods as destructive natural hazards need to be predicted in accurate way through evaluation of the hydrological response of watersheds to the effective input rainfall. Due to the variety of rainfall-runoff models, it is very important to choose a suitable model that can simulate the hydrological behavior of the watershed. In this study, various rainfall-runoff transformation methods have been evaluated, including triangular, broken triangular, variable triangular and SCS-curvilinear unit hydrograph methods in Nenekaran watershed, Ardabil province. In this regard, the Wildcat5 hydrological model have been used to this purpose. The precipitation amount at the 25-year return period was calculated using Cumfreq software. After preparing the land use map of the study area using satellite images, the area of each land use in the area has been calculated using ArcGIS software. The precipitation value and the time of concentration were considered constant during the simulation procedure. The results showed that the SCS method had the highest runoff of 44.50 cubic meters per second. The minimum time to the peak was 2.19 hours and the variable triangular method had the lowest peak flow rate. The simple triangular method has a maximum time to peak of 4.51 hours, which shows the great difference between the hydrograph of the SCS method and the other three methods. The difference in the nature of the methods, the watershed condition, and the suitability of estimating tc and CN parameters should be considered in rainfall-runoff transformation methods.
Khodayar Zeiaei; abazar esmali; Raoof Mostafazadeh; Mohammad Golshan
Abstract
1-Introduction Watersheds are physical boundaries that include natural ecosystems and all human interactions. Land-use change in watersheds has been one of the major challenges in the 21st century. According to the findings of some researchers, the effects of land use on water resources are more severe ...
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1-Introduction Watersheds are physical boundaries that include natural ecosystems and all human interactions. Land-use change in watersheds has been one of the major challenges in the 21st century. According to the findings of some researchers, the effects of land use on water resources are more severe than climate change. The estimation of streamflow in watersheds with different land uses is one of the important issues in hydrological studies. In recent years, one of the most widely used methods to facilitate computation has been the use of computer models that represent the watershed response with high accuracy. Restrictions on access to sufficient hydrological data make the role of watershed simulation models more important. This study aimed at modeling monthly runoff using the SWAT model and assessing the effects of different land-use change scenarios on runoff components. 2-Methodology The Ahl-e-Iman watershed with 7770.86 ha area is located in Ardabil province, which was selected to predict the effects of land-use change on hydrologic response. The SWAT model has been developed to simulate different parameters of the daily, monthly, and annual hydrologic responses. The curve number method in the SWAT model was used to estimate monthly surface runoff and output runoff yield. The main inputs of the SWAT model, including daily precipitation, minimum and maximum temperature, relative humidity, and wind speed, were obtained from available data centers to prepare a digital elevation map (DEM), land use map, and soil map. The SWAT CUP program was used to calibrate the model. The input of this program is observational flow data and the output file is the SWAT model. The statistical indices of Nash-Sutcliffe coefficient (NS), correlation coefficient (R2), and mean square error (MSE) were used to evaluate the simulation results of the model. 3-Results and Discussion Sensitivity analysis and the model calibration were performed in 2003-2010. The validation of the SWAT model showed that this model had a high performance for predicting the hydrologic effects of management scenarios in the Ahl Iman watershed. The results showed that the model had high performance in both periods. The obtained land-use map was given to the model to simulate the effect of land use change. The results of runoff simulation with both land uses of the study scenarios compared with the base flow are given in Figure 1. Figure (1): Comparing base flow with streamflow in the first and second land-use change scenarios 4-Conclusion The performance of the SWAT model was evaluated in both the calibration and validation periods; therefore, this model was used to investigate different land use management scenarios. The results of the first management scenario showed that the average streamflow discharge was equal to 0.3 cms, which showed 17% decrease in discharge compared to the base land use discharge (0.6 m3). The streamflow discharge increased 36% compared to the base flow in the second scenario. Therefore, this scenario will reduce the water resources of the region in a long time.
Fariba Esfandiyari Darabad; Rasoul Bakhshandeh; Masoud Rahimi; Khadijeh Haji; Raoof Mostafazadeh
Abstract
1-Introduction The changes in river processes due to river discharge and sedimentation as a primary principle driving force can affect the geometry of rivers. Determining the amount of sediment and floodplain and water quality study are prerequisites for river management operations. Any change in the ...
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1-Introduction The changes in river processes due to river discharge and sedimentation as a primary principle driving force can affect the geometry of rivers. Determining the amount of sediment and floodplain and water quality study are prerequisites for river management operations. Any change in the steady-state of the rivers will result in physical changes in the rivers and a new reaction to the rivers' behavior. Morphological studies to determine the quantity and quality of river response will predict future river behavior. The downstream river reaches of the Hamzekhanloo River basin is one of the most important agricultural areas of Germi city due to its fertile flood plains and sufficient water availability, which has undergone many changes in recent years. In this study, the Hamzekhanloo River was investigated based on the Rosgen stream classification scheme. 2-Methodology The Hec-Ras hydrodynamic model was used to simulate the Hamzekhanloo River cross-sections and floodwater capacity. The processing of the required data for modeling purposes was performed at the ArcGIS software; the classification of stream reaches was done using the Rosgen stream classification system. Rosgen classification system predicts river behavior based on morphology and hydraulic relationship and flow sediment with specific morphology. Based on Rosgen's method, morphological characteristics of rivers are investigated at four different levels but focuses more on two levels of general geomorphic properties and morphological description. Level 1 (General Classification): Describes the morphological characteristics of the river obtained by combining information on catchment, landform, and valley morphology. Level two (descriptive classification) of the river. 3-Results and Discussion The results of the Rosgen classification scheme showed that the studied river had been classified at the C class in some river reaches, which had high flood sensitivity, high vegetation control, high sediment recovery, and sediment supply potential. Also, these reaches had narrow to wide valleys, constructed from alluvial deposition with a well-developed floodplain. Meanwhile, some sections of the study river fall in the B class according to the Rosgen classification. These reaches exist primarily on moderately steep to gently sloped terrain, resulting in narrow valleys that limit the development of a wide floodplain. These streams display a low channel sinuosity, and streambank erosion rates are normally low. The sensitivity to flooding and sediment supply is high; the influence of moderate vegetation control and recovering potential is excellent. Moreover, the cross-section patterns in the river and the parameters affecting the classification and segmentation of reaches are consistent with the overall pattern on the Rosgen classification model. 4-Conclusions The river bed of the Hamzekhanloo River is a combination of rubble, gravel, and sand. Farmers and gardeners dig the riverbed and store water to irrigate the orchard fields and gardens during the summer, and crop cultivation is observed in the river bed and floodplain. Sand mining is a common activity in the river bed to carry out the development and construction purposes of the area. Sand removal from the riverbed has led to the formation of ponds within the basin, and such alterations have altered the bed and morphology of the Hamzekhanloo River. Thus, Rosgen's model can predict the geomorphic quantification of the Hamzekhanloo River and rivers with similar conditions. This type of river channel morphological classification can be used to develop engineering designs and management implications and river restoration.
Hassan Khavarian; Maryam Aghaie; Raoof Mostafazadeh
Abstract
1-IntroductionLand use change has significant effects on hydrological and ecological processes at different temporal and spatial scales. Many hydrological models have been developed based on the characteristics of the basin, available data and purpose of the study. To predict the characteristics of river ...
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1-IntroductionLand use change has significant effects on hydrological and ecological processes at different temporal and spatial scales. Many hydrological models have been developed based on the characteristics of the basin, available data and purpose of the study. To predict the characteristics of river flow, we need to develop the rainfall-runoff model to predict the flow for a long period of time. This study has been carried out for the modeling of monthly runoff using Temez model and then the effects of the different land use change scenarios on runoff components have been assessed.2-MethodologyIn this study the OLI-Landsat 8 satellite imageries, a digital elevation model (DEM) as well as meteorological and hydrological data were used for the modelling purpose. The land use classification was carried out using a support vector machine (SVM) method to create a map with 6 land use classes: dry farming, forest land, water body, pasture, built-up and irrigated agriculture. Then, the 10 management scenarios have been developed based on the field observations and taking into account the field characteristics, changes trend in the land use pattern, and the suitability of the study area for different land uses. In order to simulate the runoff, the Temez monthly hydrological model was employed. A 10-year (2002 to 2012) daily precipitation, temperature and runoff data were aggregated to monthly time scales. The calibration and validation steps were performed based on observed data. For calibration of the model, the first 6 years data and for model validation 4 years data were used. The parameters of the Temez model were calibrated based on the values obtained from the literature. First, the appropriate coefficients were found for each land use in the watershed and then the area of land uses in all scenarios were computed. Finally, the weighted average was calculated for the coefficients and appointment in Temez model. 3-Results and DiscussionThe accuracy of the land use map was quite high. A Kappa coefficient of 0.95 and an overall accuracy of 0.975 was obtained. The accuracy of the modeled runoff was presented using R2 coefficient, which was 0.77 and 0.65, for calibration and validation stages, respectively. The results of considering the land use change scenarios on the monthly runoff showed that land use reclamation scenarios of 3, 4 and 5 had a decreasing effect on the runoff by 3.4, 3.3, and 4.1 percent, respectively. Also the land use scenarios of degradation condition, 9 and 10 scenarios, caused an increasing effect on the monthly runoff to 15.24 and 4.5 percent, respectively.4- ConclusionThe monthly hydrological Temez model showed relatively good performance in estimating monthly runoff values based on the data used. The results can be considered in predicting the development and degradation conditions in the study area. Keywords: Land Reclamation, Land Degradation, Kouzehtopraghi Watershed, Land use Change Scenario, Monthly Runoff Feature, Temez Model5-ReferencesArceo, M.G.A.S., Cruz, R.V.O., TiburanJr, C.L., & Balatibat, J.B (2018). Modelling the hydrologic responses to land cover and climate changes of selected watershed in the Philippines using soil and water assessment tool (SWAT) model, DLSU Business & Economics Review, 28, 84-101.Andrade Abe, C., Lucialobo, F.O., Berhan Dibike, Y., Farias Costa, M.P.D., Dos Santos, V., & L.M Novo, E.M (2019). Modelling the effects of historical and future land cover changes on the hydrology of an Amazonian basin, Water, 10(932), 1-19.Feki, M. R., G. Gepple, A. Mille, G. Mancini, M (2018), Impact of infiltration process modelling on soil moisture content simulations for irrigation management, Water, 10(850), 1-20.Garg, V., Nikam, B.R., Thakur, P.K., Aggarwal, S.P., Gupta, P.K., & Srivastav, S.K. (2019). Human-induced land use land cover change and its impact on hydrology, HydroResearch, 1, 48-56.Gumindoga, W., Rwasoka, D.T., Ncube, N., Kaseke, E., & Dube, T (2018). Effect of land cover/land-use changes on water availability in around Ruti dam in Nyazvidzi catchment, Zimbabwe, Water, 44(1), 136-145.Hyandye, C.B. Worqul, A., Martz, L.W., & Muzuka, A.N.N. (2018). The impact of future climate and land use/cover change on water resources in the Ndembera watershed and their mitigation and adaptation strategies, Environmental System Research, 7(7), 1-24.Jain, S.K. (1993). Calibration of conceptual models for rainfall-runoff simulation, Hydrological Sciences Journal, 38(5), 431-441.Onate-Valdivieso, F., Bosque-Sendra, J., Sastre-Merline, A., & Ponce, V.M. (2016). Calibration, validation and evaluation of a lumped hydrologic model in a montain area in Southern Ecuador, Agrociencia, 50(8), 945-963.Temez, J.R (1977(. Modelo matematico de transformacion. Precipitacion. Aportacion. Asociacion de Investigacion Industrial Electrica ASINEL, 1-10.
