The Nutrient Cycling and Soil Acidification Model (NUCSAM) is derived from the Regional Soil Acidification Model (RESAM). NUCSAM simulates the major hydrological and biogeochemical processes in the forest canopy, litter layer, and mineral soil horizons. The change in soil solution and solid phase chemistry is calculated from a set of conservation equations, describing the input, output, and interactions in each compartment. Vertical heterogeneity is taken into account by differentiating between soil layers. The hydrological processes included are; partitioning of precipitation into rainfall and snow, interception and evaporation from the canopy, transpiration from the soil layers, snowpack accumulation and melt, and a one dimensional vertical transient water flow in the soil profile. For the hydrological module, an adapted version of the SWATRE model is used. An application of NUCSAM requires data for soil physical and chemical characteristics, rainfall, temperature, global radiation, precipitation and vegetation characteristics. NUCSAM has a temporal resolution of one day and is data intensive.
