Authors:M. Sayeeduzzaman and Frank Weirich Abstract:While water-repellency, devegetation and other fire effects on watersheds have been widely reported in the western United States as well as in other parts of the world, until now few models offered the scope for modeling of the hydrologic consequences of such effects, especially when intra-basin variations needed to be accounted for. To address this limitation, a new deterministic, distributed-parameter, event-oriented, watershed-scale runoff model was developed in Java. Adapting some of the core components of ANSWERS (Areal Nonpoint Source Watershed Environment Response Simulation) and combining them with additionally developed modules for representing spatial variations in hydrologic effects of fire, the new model predicts runoff under both post-fire and normal hydrologic conditions that are typically observed in mountain watersheds in the west coast of the United States. This paper presents a specific application of the model to a small, mountain watershed in California. For inputs, we used raster, ArcGIS-based data on topography, soils, surface covers, channel properties, along with hypothetical burn-intensity descriptors and zones for the watershed. We then applied the model to estimate storm runoff hydrographs for the watershed. This paper highlights the modeling process and results thereof in comparison with the recorded hydrographs from the basin.Keywords:hydrologic modeling, GIS, Java (c) Copyright 1996-2006 M. Sayeeduzzaman |