Flood water zoning using hydraulic model HEC-RAS in the GIS environment Case study: Nekarod River in the Mazandaran province

摘要

Flood water zoning, as one of flood water management non-structural methods, plays the essential role in the plan, management, use of the flood water and the limits of rivers, which makes possible to carry out hydraulic analysis. In the present study,the reach between the Nekarod River with length of 3.2km was considered. In order to determine flood water zoning, firstly, the region topographic maps with 1:1000 scale was prepared, then, the geometric specification file of the study case span in theArcGIS environment using HEC-GeoRAS lateral program, is provided; so, it was transformed to HEC-RAS model and after conducting hydraulic calculation and modeling current over HEC-RAS software, their results is transformed in to GIS environment. Flood zoning was determined for the other different return period (from 5 to 200 years old) According to the results to be more precision than used method, to be lower time taken to obtain final results, to be low cost in the light of economy, are the advantagesof this method in comparison with the other method flood water zoning.