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. ...
Read More
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.
Mohammad Omidfar; Hashem Rostamzadeh; Behroz Sari Sarraf
Volume 5, Issue 15 , October 2018, , Pages 135-152
Abstract
Abstract
Introduction
Flood phenomenon is one of the atmospheric hazards whose frecuncy is remarkable in the northwest of Iran and every year, there are a lot of Casualties and financial losses on different parts of the study area. The aim of this study was the feasibility of using the new Doppler ...
Read More
Abstract
Introduction
Flood phenomenon is one of the atmospheric hazards whose frecuncy is remarkable in the northwest of Iran and every year, there are a lot of Casualties and financial losses on different parts of the study area. The aim of this study was the feasibility of using the new Doppler radar technology to predict the short term flood phenomenon and send timely warning to the relevant organizations and residents of the flood prone areas. To this end, Tabriz Radar products, which can be expanded in a three dimentional structure based on the direction and speed of movement and water content of cloudes in the event of flood of the gallezar village, were selected and carefully monitored. The resuls showed that due to the ability of the radar to penetrate into the clouds and its appropriate spatial and temporal resolution, depending on the formation location and the speed of development of super cells, flood phenomena can be detected several hours before the occurrence. In case of coordination with the crisis organization and prompt warning, it can decrease its damages.
In recent years, Doppler weather radar is one of the new remote sensing technologies that can give valuable information about cloud and type of precipitation. The new technology of meteorology radar can be fruitful in the identification, monitoring, and early warning, and, eventually, reducing damage inflicted to the environment. Therefore, this study aimed to evaluate the efficiency of the products of Doppler radar in monitoring the cells of showery severe rain-producing clouds. The aim of this study was also to evaluate the performance and functional advantages of radars in monitoring and analyzing the characteristics of flash flooding covective cells in the northwest of Iran. For this aim, the production or incoming , direction of motion, and attenuation of floodable convective cells in the study area were monitored by 15-minute time steps by three main radar products including maximum display (MAX), surface rainfall intensity (SRI), and precitipation accumulation. The obtained results can be applied in establishing scientific information and missions in establishing rapid meteorological warning system and, hence, making required decisions in reducing casualties brought about by flood.
Methodology
The area under study is part of the northwest of Iran that is located in the effective range of Tabriz radar. According to the power of the radar waves, its effective range can be used up to 250 km radius. For analytical studies, like this study, it is applicable to the whole range of the northwest of the country. A variety of radar products produced by the radar reaches to more than fifty products. Each product has different output specifications and performance with graphics, charts, and meteorological signs. Of these products, about 20 products are generated and stored by Tabriz radar. Some of the applied products in this study will be briefly discussed. The maximum product of the exhibition is displayed on a graphical screen after processing. It contains information which displays the maximum height and interior density of the cloud. Surface rainfall intensity product showed the intensity of precipitation at a specific level. For this purpose, a surface close to the ground was determined and by the equation between Z-R, the value of z reflection was transformed to the intensity of the rainfall. To achieve the objectives of the study, Azarshahr flood event, which occurred in 2017, was selected using the currently reported weather codes in synoptic stations in the studied area. In sampling, there was an atempt to place cases in different geographical distances and directions with respect to the radar. For the close monitoring of the showers, from the early days of the reported barrage above, the radar products were examined with 15-minute intervals. On the basis of these images, time and place, route, time and peak locations of the activities, and the death of rainfall cell were monitored.
Result and Discussion
In this study, floodable convective cloud cells producing heavy rain showers grew within a few hours from small cumulus clouds (type one without rainfall), into cumulonimbus flood-causing clouds, along with heavy rainfall and hail. The 4 April 2017 flood event convective rainfalls, which created heavy rains in small area was selected. Naturally, in the selected case, the rest of the stations had meager amount of rainfall that was not possible to recognize these convective cells with satellite images or by synoptic maps. Doppler radars had tremendous role in detecting, routing, and monitoring of the maps. Indeeed, with proper management and timely warning, a significant amount of the casualties caused by the phenomenon can be decreased. Cooperation with the crisis organization and prompt warning can also decrease its damages.
Conclusion
Doppler radars have great potential to improve the quality of the rainfall data because of the ability of producing data with a spatial resolution of less than 500 m and 15-minute temporal resolution and its wide coverage. The results showed that the flood event which occurred on April 4th, 2017 was a local rainfall. It was formed in a short time and at a relatively small scale and was invisible by meteorological observations and satellite images. Primary cloud cell (cumulonimbus) of an intense shower rain was formed in the early hours of the morning and gradually was grown and reached the strongest form in the afternoon and early evening and created an intense flood in the form of a shower rain. After intense rainfall event, the cloud cells became weak and collapsed. In some cases, the peak of its convective clouds got to 10 km.
Hashem Rostamzadeh; Mohammad Reza Nikjoo; Ismaeil Asadi; Jafar Jafarzadeh
Volume 2, Issue 3 , January 2017, , Pages 43-60
Abstract
Ardabil Plain is an intermountain area of approximately 820 square kilometers in northwestern Iran, located in the eastern plateau of Azerbaijan within the province of Ardabil. Plain water needed for agriculture, industry and drinking are provided from rivers, deep and semi-deep wells and springs in ...
Read More
Ardabil Plain is an intermountain area of approximately 820 square kilometers in northwestern Iran, located in the eastern plateau of Azerbaijan within the province of Ardabil. Plain water needed for agriculture, industry and drinking are provided from rivers, deep and semi-deep wells and springs in the current area. To check the quality of groundwater in Ardabil, the data on 56 deep wells, 3 semi-deep wells, 3 aqueducts and fountains, and 7 mouthpiece of streams based on 1389 Regional Water Authority records were sampled. The purpose of this study was to provide an overview of the quality of potable groundwater of Ardabil Plain by using electrical conductivity, PH, SO4--, Cl-, Na and total hardness (in CaCo3) and geostatistical techniques in GIS software through ArcGIS10.3 to produce thematic maps of groundwater quality is Ardabil Plain. The ordinary kriging interpolation method to obtain the spatial distribution of parameters and simple additive weight for weighting and ranking layers were also used. Finally, with regard to the quality of the final map, it was detected that approximately 34 percent (about 280 kilometers) of groundwater for drinking at an optimal level in Ardabil Plain is located on the east side and that the lower quality water belonged to the southwest and northwest of the plain. Also, it was found that there is a direct relationship between the density of population and density of existing wells in the Plain.
