To Evaluation the Rate of Run Off Hydrographs of Floods in Mansourabad Watershed Basin of South khorasan Using SCS Abstraction Parameters and Compared with the Curve method D.jlaly

Abstract

Estimation of runoff through the rivers, they can provide ways to deal with floods and also provide guidelines for the management and efficiency of this natural event. River and stream flow estimates in recent years has shown that it can be used in various ways to estimate flood region and the effectiveness of procedures, discuss. Study to estimate the rate of flow using soil conservation service (SCS) and compared with the curve of the catchment has Mansourabad in South khorasan. Thus, this study is the first use of the SCS, the runoff area of study using observational data and calculations are obtained. For the purpose of calculating the runoff curve number (CN), using vegetation maps, land use and soil hydrologic groups with the use of geographic information systems (GIS) and satellite imagery was used to end the curve No. 69/25, respectively. Then the number of curves to 5 flood event registered Mansourabad gauging station located in the outlet area of the rain rate statistics, which were calculated as 72/83, 84/38, 73/05, 69/78 and 90/5 respectively. The results indicate a 89 percent match between the calculated and observed curve numbers and ultimately the effectiveness of the SCS. Then compare the results of different flood return period floods SCS curve obtained by the method Curve method D.jlaly paid to efficient method selected. Results there were a significant difference between the two runoff anecdote that illustrates the lack of efficiency curve of the low computational parameters for the field.