Two-Dimetional Hydraulic Simulation of Floods using the LISFLOOD-FP Raster Model (A Case Study: The Shemshak Watershed, Tehran Province)

LISFLOOD-FP belongs to a new generation of hydrodynamic models of flood simulation, which is implemented by a digital elevation map for the river and the waterways, route information and flow rates The LISFLOOD-FP features are two-dimensional hydraulic models: 1. based on raster 2. large scale 3. ease of formulation and high computational efficiency 4. simplicity of use 5. spatial adjustment of computations adaptively by the model itself 6. the ability to use the rivers with a width smaller than the dimensions of DEM pixels 7. the possibility of integration with fully distributed hydrological model such as WetSpa. These are the advantages of LISFLOOD-FP compared to other two-dimensional hydraulic models. Today, two-dimensional hydraulic models which are based on raster has become increasingly popular due to the development of personal computer processing capacity as well as ease of access to high-resolution topographic digital maps. The present study determined hydraulic behavior of flooding and water level in different return periods in Shemshak watershed using a LISFLOOD-FP two-dimensional hydraulic model. In this regard, the digital elevation model (DEM) was used with a spatial resolution of 2 meters. Finally, the data were entered into the model and analyzed. The results indicated that the model is efficient in floods simulation and showed that the river course is vulnerable against flood in one part of the main branch of Darbandsar and in the junction of Shemshak and Darbandsar in Dorood while it has less vulnerability in some other areas.