| The process-based WEP (Water and Energy Processes) hydrologic model was initially developed at the Public Works Research Institute, Japan as a tool for extensive analysis of water and evergy budgets at catchment scale, and later enhanced by incorporating N and P components. The discharge-based modeling observation points, however, the dissolved P (DP) and particulate N and P (PN, PP) dynamics were not adequately differ in many aspects, thus adequate caution is needed in modeling those associated processes distinctively in detail. In contrast to N where up to 35 %-90% is transported in dissolved form, the loading of P occures mainly with particulate matter erosion and the portion of PP transport in a watershed can be up to 45%-90%, and does not solely depend on discharge alone. Thus, in the present study, an attempt was made to further improve WEP model by coupling a soil erosion-transport module to introduce sediment-boud pollutant (N, P) components, targeting integrated river basin management and decision support system for best management practices. |
