A New GIS Technique for Runoff Modeling and Depression Storage Assessment

Abstract

This study aimed to develop a grid-based model that can use raster data (DEM) to generate digital Elevation model free of Depressions and their corresponding catchments considering different parameters (i.e., Rainfall depth, CN values and threshold for the depression area). This model is developed by GIS model builder and some Python scripts. Also, an assessment is done on a filled depression through a storm and its effects on runoff volume and peak discharge by using GIS tools and HEC-HMS. This chapter presents conclusions of the developed model and its applications on two study area with different terrain. Also, shows results of assessment of depression impact on runoff volume and peak discharge. All are used to propose recommendations for future work. GIS developed model (DGDEM) has an ability to extract depressions and their corresponding catchments to consider only depression and their corresponding catchments without using fill sink tool. Also, determination of outlet configuration that has the best results in calculating runoff volume and peak discharge.