Hashem Rostamzadeh; Mir Kamel Hosseini; Saeed Jahanbakhsh asl; Mohammad Omidfar
Abstract
The aim of this research is to investigate the accuracy of the heavy rainfall data (rainfalls of 25 mm or more) of Tabriz weather radar in a period of 8 years (2014-2021) and compare them with synoptic station data in basin. To compare and evaluate between meteorological stations and radar data, statistics ...
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The aim of this research is to investigate the accuracy of the heavy rainfall data (rainfalls of 25 mm or more) of Tabriz weather radar in a period of 8 years (2014-2021) and compare them with synoptic station data in basin. To compare and evaluate between meteorological stations and radar data, statistics such as, correlation coefficient (R) and root mean square error (RMSE) were used. The comparison of the maps obtained from Doppler radar and rain gauge stations showed that the spatial distribution of precipitation from the two databases was not the same and the low and high rainfall areas did not match each other, so that the correlation coefficient between the radar and observed precipitation was 0.25. Also, the results of Kolmogorov-Smirnov test showed that considering that the obtained p-value (0.000) is smaller than the error value of the test (0.05), then the difference between radar precipitation data and ground observations is significant. In fact, the rainfall values recorded in the ground and radar stations do not provide a single result, and none of the statistical populations have a uniform distribution, therefore the radar rainfall data cannot be used instead of the rainfall data of the stations.
Saeed Jahanbakhsh Asl; Majid Rezaee Banafshe; Hashem Rostamzadeh; Mohammad Hossein Aalinejad
Volume 5, Issue 16 , December 2018, , Pages 101-118
Abstract
Abstract
Introduction
Continuous simulation of rainfall-runoff is very important in many hydrological studies, including the effect of climate change on river flow, flood forecasting, and water resource planning. This phenomenon requires the identification of its components and formative variables. ...
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Abstract
Introduction
Continuous simulation of rainfall-runoff is very important in many hydrological studies, including the effect of climate change on river flow, flood forecasting, and water resource planning. This phenomenon requires the identification of its components and formative variables. One of the most important hydrological calculations for a basin is the determination of the relationship between rainfall and runoff. The amount of water conversion from rainfall to runoff volume depends on the climatic and the physical parameters of the basin. In the hydrological calculations of a basin, determining the relationship between rainfall and runoff is very important. Accurate calculation of precipitation and runoff at the basin level depends on the identification of its components, form-providing variables, and the use of an appropriate dependent model. The HEC-HMS software is a simulation-based hydrologic modeling software (with parameter optimization capability) developed by the US Army Hydrological Engineering Center whose first edition was presented in 1967 (Hydrologic Engineering Center, 2000: 4). In addition, in order to increase the accuracy of the input information entering into the HEC-HMS software, the HEC-GeoHMS has created an add-on called HEC-GeoHMS. One of the most important applications of this software is calibrating and estimating hydrological parameters in catchment areas. Due to the importance and the extent of using this software, many studies have been done.
Methodology
The catchment area of the city of Uremia is located in the western part of Lake Urmia. Its approximate area is 167.75 km2 and its geographical location is between 82 ° 44 'and 58 ° 44' eastern longitude and 32 ° 37 'to 48 ° 37' northern latitude. The height of the altimeter station is 1591 m and the maximum height of the basin (located on the border between Iran and Turkey) is 3574 m. Figure 1 shows the location of the Urmia Shahirchay basin in the watersheds of Iran and Lake Urmia. In this study, the HEC-HMS model was used to simulate surface runoff. In addition, the HEC-GEOHMS integration was used to map the basin model. For this purpose, the data of the temperature and the precipitation data of the synoptic station of Urmia and the daily flow rate of the river flow at the hydrometric station of the Bardesour (located at the outlet of the basin) were used.
Result
By obtaining the basin model by the HEC-GEOHMS add-on in ARCGIS software and creating climatological models, controlling and entering other necessary parameters of the model was implemented. In simulation of rainfall-runoff of Chacha basin by HEC-HMS model, in the period of 2004-2013, the best calibration and validation period was selected to minimize simulation error. The base course was divided into two calibration (2004-2010) and validation (2010-2013) periods. The calculation of this parameter is necessary for simulation in mountainous basins, which are mostly snowfall. In this study, the temperature index method, one of the complementary methods of day-to-day modeling of snow modeling, was used. One particular way is to consider the specific amount of snow melting for any temperature above freezing point. For this purpose, the catchment area was divided into altitudinal classes and the percentage of area of each sub-basin in each altitude region was introduced into the model.
Discussion and Conclusion
Based on the results of the simulation in the calibration and validation periods, as well as the evaluation criteria of the model, it was found that the HEC-HMS model had a high probability in rainfall-runoff simulation of Shahrchay basin. It should be noted that the use of the HEC-GEOHMS in the design of the basin model has played a large role in increasing its accuracy in rainfall-runoff simulation. In Yacoby's (2013) study, the accuracy of this model in the simulation of runoff was weaker than other models. It was probably due to not using the HEC-GEOHMS add-on and the lack of a synoptic station in the study area. Nevertheless, in other studies (e.g., Verenden et al., 2013; Borhani Daryan et al., 2016), the HECGEO-HMS add-on was a good result of the model's work, which is consistent with the current study. The results of this study indicate the ability of the HEC-HMS model to simulate the hydrologic behavior of the Chacha basin. In addition, the ability to use the GIS to accurately provide input for the model and view the output shows the efficiency of their integration. The present integration, with proper hydrometric data and precipitation, is able to accurately simulate rainfall-runoff phenomena.
Saeed Jahanbakhsh Asl; Yaghoub Dinpajouh; Mohammad Hossein Alinejad
Volume 2, Issue 5 , January 2017, , Pages 101-117
Abstract
Saeed Jahanbakhsh Asl[1] Yaghoub Dinpajouh[2] Mohammad Hossein Aalinejad[3]* Abstract In this study for the purpose of simulation of runoff originated from snowmelt in Shahrchay River basin two models namely SRM and HEC-HMS were used. For this purpose, entering the snow cover data, meteorological ...
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Saeed Jahanbakhsh Asl[1] Yaghoub Dinpajouh[2] Mohammad Hossein Aalinejad[3]* Abstract In this study for the purpose of simulation of runoff originated from snowmelt in Shahrchay River basin two models namely SRM and HEC-HMS were used. For this purpose, entering the snow cover data, meteorological variables and other needed parameters an input to SRM model the runoff from snowmelt was simulate. In HEC-HMS model, after derivation of watershed model using the HEC-GEOHMS software in GIS environment and derivation of meteorology model and entering the required parameters such as water losses, flow routing and snow melt was simulated. The coefficient of determination (R2) of SRM model was 0.9 and the percentage of volumetric error (DV) was equal to 1.96. On the other hand, the HEC-HMS model simulated snowmelt runoff was satisfactory (but less than SRM), so that the R2 and DV obtained for this model were as equal to 0.85 and 2.1%, respectively. Utilization of air temperature and precipitation data (neglecting the high accuracy of SRM) can be considered as advantages of HEC-HMS. In contrast, in SRM model in the snow covered area of region apart from the mentioned parameters satellite images of the region is also required. Results indicated that the total volume of runoff in the study area was 129.9×106 cubic meters for SRM, whereas it was 129.6×106 cubic meters for HEC-HMS. Comparing these values with that of the observed (i.e.134.4×106 m3) it can be concluded that SRM model performance is relatively better than the HEC-HMS. [1]- Professor, Department of Meteorological, the University of Tabriz. [2]- Associate Professor of Water Engineering, the University of Tabriz. [3]- M.A. student in Meteorological, the University of Tabriz (Corresponding author), Email:aalineghad63@yahoo.com.
Saeed Jahanbakhsh Asl; Alimohammad Khorshiddoust; Mohammad Hossein Alinejad; Farnaz Pourasghr
Volume 3, Issue 7 , October 2016, , Pages 107-122
Abstract
Saeed Jahanbakhsh Asl[1]* Alimohammad Khorshidoust [2] Mohammad Hossein Aalinejad[3] Farnaz Pourasghar[4] Abstract Temperature and precipitation are two important parameters in hydrology and water resources. The impact of climate change on these two parameters has been the subject of many studies and ...
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Saeed Jahanbakhsh Asl[1]* Alimohammad Khorshidoust [2] Mohammad Hossein Aalinejad[3] Farnaz Pourasghar[4] Abstract Temperature and precipitation are two important parameters in hydrology and water resources. The impact of climate change on these two parameters has been the subject of many studies and studying atmospheric general circulation models is one of the best methods to estimate its effects. In the studies of climate change, lack of uncertainty in various stages of evaluation for the effect of climate change reduce certainty and confidence of the final outputs. In this study for analyzing the effects of climate change on precipitation and temperature in Shahrchay basin and the effects of the uncertainty related to general circulation models, six atmospheric general circulation model and 3 scenarios, A1B, A2 and B1 were downscaled by using LARS-WG. For evaluating the uncertainty of the models and scenarios, the output of models in the future and based period were compared by monthly statistical indices, coefficient of determination (R2) and Root Mean Square Error (RMSE) and the best models and scenarios for producing temperature and precipitation data were selected for the period 2011-2030. As the results, the HADCM3 model under scenarios A1B was used for precipitation and the MPEH5 under scenarios A2 for temperature production. The results of this research showed that in the future period rainfall will be reduced about 9 millimeter, while the minimum and maximum temperature will increase 1.05 and 0.87 °C respectively. Disruptions of rainfall distribution and high temperature have significantly negative consequences than rainfall reduction. [1]- Professor in Department of Meteorological, University of Tabriz, (Corresponding Autor), Email:s_jahan@tabrizu.ac.ir. [2]- Professor in Department of Meteorological, University of Tabriz. [3]- Meteorological Graduate Student of Tabriz Universit, Email:aalineghad63@yahoo.com. [4]- Climatology Ph.D., Meteorology Directorate General of East Azerbaijan Province.
