PnET-II3SL/SWAT: Modeling the Combined Effects of Forests and Agriculture on Water Availability

Abstract

The climate change and variability phenomenon, because of its potential to exert significant influences on the hydrologic cycle, the economy, and human society as a whole, has drawn considerable attention from the scientific community and government agencies worldwide. In response to growing concerns, we are attempting to expand our understanding of the relationship between land-use heterogeneities, water availability, and climate change/variability in the southeastern United States. Specifically, this paper describes the coupling and validation of a hydrologic-forest productivity model (PnET-II3SL) with a hydrologic-agricultural productivity model to represent the hydrologic response characteristics of large spatial areas. The resulting code is capable of generating scientifically sound predictions of the effects of future climatic conditions, with regards to water availability, in the heterogeneous watersheds of the southeast. Validation efforts are described, utilizing long-term historical records, for 12 experimental watersheds. Selected sites represent a diversity of climatic regimes, topographic conditions, soil types, area, and vegetal species.