Dynamics monitoring and disaster assessment for watershed management using time-series satellite images

This paper presents a mechanism that utilizes intensive multitemporal and multisensor satellite images to monitor land cover dynamics. The proposed approach could be applied for regular dynamics monitoring, disaster monitoring and assessment, and vegetation recovery after natural disasters. The disaster monitoring and assessment are the most important issues imbedded in the program. This paper gives an example using the proposed mechanism to cover a major watershed in Taiwan. Often natural hazards such as typhoons or earthquakes trigger landslides or debris flows, which can deliver large amounts of sediment into a reservoir, decreasing its capacity for water storage. Disaster assessment prior to decision-making and support efforts is a must. Three major typhoons that happened in 2004 and 2005 will be discussed here. The proposed mechanism is demonstrated to be feasible, practical, and effective, since with it we are able to generate disaster assessment in a shorter time than with on-site or aerial-photo surveying alone provided that intensive satellite images are available.