3D volumetric soft geo-objects for dynamic urban runoff modeling

Abstract

Complexities of streamflow structures, drainage systems, sewers and urban landscape render difficulties for urban flood mitigation and rehabilitation planning towards reducing urban flood disaster. GIS has been useful for the investigation of urban runoff spatial patterns. However, the inability of GIS to realistically explore the momentum and continuity aspects of overland flow and urban runoff process has been proven to be the shortcomings of the system. This leads to the requirement of an extended dimension representing dynamic soft geometrical volumes of urban stormwater runoff. The inclusion of Volumetric Soft Geo-objects (VSG) offers a comprehensive and practical 3D dynamic modeling of urban runoff volume. The VSG are driven based on Kinematic Wave Routing and Green-Ampt method for modeling open channel flow and overland flow volume respectively. Basin model, sub-basin, reach and junction elements are extracted from Digital Elevation Model (DEM) with 5 meter resolution using the HEC-GeoHMS program and the HEC-HMS model. The modeled results of discharge volume gave an R2 of 0.88 and a Nash–Sutcliffe coefficient of 0.82, indicating that VSG provides end-users the prospect to envision complex information of flood disaster management.