DESIGN AND IMPLEMENTATION OF A WEB BASED GIS FOR FLOOD DISASTER MANAGEMENT: CASE STUDY OF NOWSHERA DISTRICT

Abstract

Natural disasters have been increasing worldwide in recent years, including floods, snow, and typhoons disasters. Flooding is the most frequent natural disaster in many countries and is increasingly a concern with climate change. The objective of this study is to develop a prototype version of a Web GIS-based disaster management system (WebGISDMS) using the HEC RAS Model and ArcGIS Server to enhance on-time operation. The selected study area comprised of 30 km of River Kabul and a 10 km tributary reach of Kalpani River. The data used include ASTER 30-m digital elevation model (DEM) downloaded from earthexploler.usgs.gov, flood discharge data were collected from irrigation department Peshawar, satellite imageries data of Landsat 30-m downloaded from glovis.usgs.gov, land use map generated from the classified image and assigned every Land use land cover class Manning‟s n values defined in HEC-RAS reference manual version 4.1. HEC-GeoRAS was used to develop the RAS layers including River Centerline, banks, flow paths, cross-sections, bridges, ineffective areas and blocked obstructions from Triangulated Irregular Network (TIN). The RAS layers were exported to HEC RAS where bridges data and flow data were also included to it for steady flow analysis. Finally the post processing of model was used to generate flood inundation map which shows the flood extent and depth in the study area. From ArcGIS desktop the resulted data were published and shared as a web services at ArcGIS Server. ArcGIS viewer for flex was used as a web mapping application for a web client application which can be accessed and used now in web browser.