Soil loss and its transport processes were coupled with an existing distributed hydrological modelto assess the effects of land use change on stream flow and suspended sediment load in the ChaoPhraya River basin, Thailand. The simulation period spanned from 2001 to 2010. The resultsindicate that the Nash-Sutcliffe efficiency of upper sub-basins fluctuated in the range 0.51- 0.72,indicating the applicability of the model for longterm simulation at the monthly scale. Land usechange during 200l-2010 caused a 1.6% increase in suspended sediment load based on the presenttrend. The changes were particularly pronounced in the Wang River basin, where the delivery ratiowas highest. Moreover, the urbanization and conversion of farm land from paddy fields exertednegative effects on sediment runoff in Chao Phraya River basin. The proposed model has theability to quantitatively evaluate the heterogeneity of sediment runoff in the basin, demonstratingthe benefits and trade-offs of each land use change class. The results of this study can support basinand local land development policy to control sediment losses during development. |