Nafiseh Moghaddasi; Vahedberdi Sheikh; Ali Najafinejad; Iman Karimirad
Abstract
The aim of this study was to evaluate the effects of mechanical watershed management measures implemented across the Boostan Dam Watershed on reduction of flood peak. To this end, the Watershed Modeling System (WMS) was used to compare peak flow before and after of implementation of the ...
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The aim of this study was to evaluate the effects of mechanical watershed management measures implemented across the Boostan Dam Watershed on reduction of flood peak. To this end, the Watershed Modeling System (WMS) was used to compare peak flow before and after of implementation of the measures. The mechanical measures have been implemented during 2000–2007. The major soil and water conservation measures in the Boostan Dam Watershed were mechanical and biological measures implemented in a limited area. To determine the effect of these measures, the watershed has been modeled in WMS environment. Five flood events occurred before implementation of the measures were used for calibration and validation of the model. Three other flood events occurred after completion of the measures were then used for the evaluation. The results showed that the mechanical measures, despite the fact that their reservoirs are full of sediment, decrease the average peak flow 1.79 % compared to the absence of these measures and if some structures would not be destructed, the reduction would reach 5.95 percent. It should be noted that if the structures were out of sediment, the average peak flow rate would decrease 3.25 % in comparison with current situation and 7.64 % when compared to absence of structures.
Raouf Mostafazadeh; Amir Sadoddin; Abdolreza Bahremand; Vahedbordi Sheikh; Habib Nazarnejad
Volume 2, Issue 2 , July 2010, , Pages 83-93
Abstract
Assessment of flood control projects in the same conditions is essential in order to improve decision making that assist us in watershed management purposes. Focus of this study is on assessing hydrological effects of the Jafar-Abad watershed management project. The study area (109 km2) located in north ...
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Assessment of flood control projects in the same conditions is essential in order to improve decision making that assist us in watershed management purposes. Focus of this study is on assessing hydrological effects of the Jafar-Abad watershed management project. The study area (109 km2) located in north of Iran in the Golestan province. Paired t-tests were performed for Indicators of Hydrologic Alteration (IHA) in Taghi-Abad gauging station, located in the outlet of the catchment, before and after construction of 58 check dams. HEC-HMS model was calibrated using 12 storm events and validated for study area. Calibrated HEC-HMS model was applied to rainfall-runoff modeling in sub-catchments and Level-pool method used for reservoir elements. Design flood hydrographs for 2-100 year return periods were simulated for both before and after check dams construction periods. The results of statistical analysis indicate that existing flood control measures had no significant impact on the hydrologic characteristics measured by IHA in 95% confidence level. The results indicated that constructed structures do not have important effect on IHAs and the amount of these effects was less than 1.5 percent in all cases. Also, by increasing in return period, the effects of structures on peak discharge and flood volume were reduced.
