Geospatial Forum: Dr. Pankaj Agarwal

Speaker: Dr. Pankaj Agarwal | RJR Nabisco Distinguished Professor of Computer Science and Professor of Mathematics | Duke University

Presentation Title: Flood Risk Analysis on Terrains

Abstract: An important problem in terrain analysis is modeling how water flows across a terrain and creates floods by filling up depressions. In this Forum, we will discuss a number of flood-risk related problems: Given a terrain T, represented as a triangulated xy-monotone surface with n vertices, a rain distribution R and a volume of rain V, determine which portions of T are flooded and how water flows across the terrain. We present efficient algorithms for flood-risk analysis under both single-flow-direction (SFD) as well as multi-flow-directions (MFD) models — in the former, water at a point can flow along one downward slope edge while in the latter, water can flow along multiple downward slope edges; the latter more accurately represents flooding events, however, it is more computationally challenging. We will also discuss these problems when there is uncertainty in terrain data, which must be incorporated into the terrain analysis.