A Study on Pulsing Sediment for Watersheds

Centralized output of sediment energy in watersheds could be regarded as oscillation of pulsing energy to the system. It usually causes serious hazards and huge damages to human society. The catastrophic impact of sediment disaster shows the importance and the difficulty in sediment transport prevention. Based on literatures review and case studies, this paper introduces the pulsing phenomenon existing in nature to interpret destructive power and balance of pulsing energy, and attempts to establish a pulsing eco-model based on the Systems Ecology approach to discuss natural hazards and their interactive behaviors accompanied with the system energy. The pulsing energy patterns of the landslide events are described in the model. From the case study of Feitsui reservoir watershed, we observe that the magnitude of pulsing sediment has a close relationship between the concentrating rainfall and the available material of sediment. In addition, the simulation results show that higher magnitude pulsing occurs less frequently but causes hazards/incident more easily. In order to prevent mighty pulsing sediment, the effect of energy accumulation should be considered in sediment treatments, and thereby enables the watershed ecosystem a better function of self-organization.