Application of GIS for Flood Zoning Hazard in Shiraz

Abstract

Flood can be occurred due to the different reasons. One of the new and challenging reasons in twenty-first century is land use changing issue. Environmental factors cause these events and the scrutiny of them shows that Human intervention in the natural water cycle through the vegetation in the aquifer of urban development and industrialization of societies has Unfavorable effects on Catchment Hydrology and causes flood intensity, increased pollution in downstream areas, Base flow and groundwater feeding reduction. Flooding is a complex and destructive natural phenomenon that causes a great damage every year. In order to plan for optimum utilization and natural flood control, which is the most important issue on earth and also in this country, more studies and much research is needed. Methodology: In this study, first the required data and statistics and information were obtained from the relevant organizations. This data includes 1:25000 maps, geological maps, satellite images and meteorological data. After applying necessary modifications on topographic maps and extracting Digital Elevation layer, the boundary of Catchment basin of Dry River will be extracted. Then using the SCS method, maximum possible runoff in the catchment is estimated. Hydrologic soil group, land use, type of Agriculture and hydrological status is calculated to obtain the CN. Findings: the result of SCS model shows that upstream land with High slope and bare lands and impermeable soils are more distributed and the Soil retention coefficient is low. Therefore the rate of runoff is also higher. By increasing the runoff on the surface of upstream land, maximum flow rate is also increased. With this increase the flood zones are more submerged. Conclusion: The investigation of the dry river shows that the amount of erosion and destruction of river margin in the straight and swept way in places with vegetation is more than the places with no vegetation “live” template. The various components of your paper [title, text, heads, etc.] are already defined on the style sheet, as illustrated by the portions given in this document.