Ecology, Environment and Conservation Paper

MANAGEMENT OF FORECASTING AND FLOOD ENCROACHMENT AND DETERMINE CRITICAL BOUNDS IN GOLESTAN RIVERS WITH GIS

Abstract

Flood is often said to be a phenomenon that leaves harmful effects by submerging lands and coastal areas. Flood control is in fact said to all preparations and methods that lead to the reduction of the harmful effects of a flood. The point we want to reach in this paper, is to find out the rate of the submergence of the flood plains in the edges of the rivers with different return period discharges in Golestan province of Iran. Since the data periods in stations are different and because of the fact that some stations were established in the area from 1337 to the recent years, after surveying and doing the competence data test based on Matusen Fon relation, the data period was selected from 1350 up to now. Among the mentioned stations, some were newly- built and some had a lot of lost data, so, their data was not enough in the best fit test and therefore was removed. After completing and prolonging this data by means of SMADA software, HEC-SSP software was used in order to estimate the maximum instantaneous discharge of these stations with different return periods. Then, the file of geometrical characteristics of the sections of the flood channels of the basin under study was provided in HEC-GeoRAS and then was exported from GIS to HEC-RAS. Then the flood Encroachment for the rivers of the area was done by the flood hydrographs with different return periods which was obtained by HEC-SSP software, and the area under threat was specified.