Soil erosion, population pressure and conservation strategies in the Riam Kanan Catchment, Indonesia

This thesis studies the Riam Kanan Catchment (RKC), located in Indonesia, in order to: evaluate the effect of land use on runoff, erosion and soil properties; examine rainfall-runoff-erosion relationships under different land use types; evaluate the suitability of runoff and soil erosion models; develop an understanding of the interaction between physical, demographic, socio-economic and political aspects in relation to soil erosion; evaluate population pressure and its impacts; develop a suitable methodology for identifying potential erosion hazard areas; and develop suitable soil conservation strategies. Rainfall pattern and water level fluctuation; changes in runoff, erosion and soil properties under different land use types; relationships between soil properties as well as between rainfall and runoff-erosion; population pressure; and potential hazard areas were all analysed. Selected runoff and erosion models were evaluated for their suitability, and soil conservation strategies were developed, considering physical, demographic, socio-economic and political aspects. Results show that changes in inflow patterns are most likely due to changes in volumes of surface and subsurface runoff values; erosion in RKC is occurring at various levels depending on the land use types; there is a relationship between rainfall-runoff and erosion parameters; population pressure is above the critical limit and can be reduced by various methods; and RKC has a moderate to high erosion hazard. The soil conservation strategies outlined in this study appear promising