Abstract:
Exposure of Pakistan to natural hazards especially floods warrants use of latest
technology to forecast the risk and vulnerabilities. GIS and Remote Sensing techniques can play
a vital role in this regard. GIS based hydrological modeling provides solutions to predict
different situations which can arise during the event of floods. This specialized GIS softwares
based analysis approach has never been tested with its full capabilities in Pakistan. This research
focuses on the preparation of calibrated model using recorded discharge / stage data during
Floods 2010 between Guddu and Sukkur Barrages on River Indus. A high resolution contour
(Sm) and satellite (1 Om) Digital Elevation Models are used as a base for integrating lay of
ground with meticulously selected manning's coefficients for variable land use and land cover of
the flood plain to calibrate the model in relation to actual recorded data. After integrating
numerous factors including elevation, land use land cover, layout of embankments and river
course of smaller area in ArcGIS the model was calibrated using steady flow analysis in HEC
RAS. An accuracy of 8-10% in relation to recorded values was achieved and the model was then
implemented on complete study area i.e. Guddu-Sukkur reach of River Indus. As a final result,
inundation, water level and embankment vulnerability maps were generated using calibrated
model.
