Acid Rain Model: Hydrologic Module

The acid rain model has been developed to simulate lake-watershed acidification processes. It provides a quantitative linkage between atmospheric deposition and lake water chemistry. The continuous simulation model is comprised of several modules including watershed hydrology, stream and lake hydraulics, canopy, snow, soil, stream and lake chemistry. The hydrology module simulates the processes of interception, throughfall, evapotranspiration, freezing and thawing of soil, and snow accumulation and melting. The model segregates the watershed horizontally into subcatchments and vertically into soil layers. Flows are routed through a layered soil profile to the streams and ultimately to the lake. Incoming precipitation and deep groundwater flow. Application of the model to Panther and Woods Lake basins in the Adirondack mountains of New York indicates the importance of flowpaths in determining lake water acidity.