Impact analysis and appraisal of Tangjiashan Barrier Lake by spatial information technology

Tangjiashan Barrier Lake is one of the most dangerous induced disasters in the great Wenchuan Earthquake. In this paper, spatial information such as synthetic aperture radar, Multi-spectrum remote sensing imagery and DEM is utilized to fast acquire characteristic parameters of Barrier Lake, such as storage capacity in different water level, the retain ability and the flood area, etc. The impact analysis and appraisal of Tangjiashan Barrier Lake are available by overlay between spatial information and calculation of the hydrodynamics model. Several hydrodynamics model computations are worked out according to different scheme and different assumed water level. The spatial information overlaid by calculational results demonstrates disaster´s space-time distribution of Tangjiashan Barrier Lake´s break. The result shows that the spatial information processing method will provide information in a fast and accurate manner for the Barrier Lake monitoring. It will provide an early warning to the goverment and provides a valuable reference for decision-maker as well.