Abstract -- Taiwan has unique topography to form steep streams which causes debris flows happen frequently in the upper stream areas. This research trys to establish a scientific approach to indicate the major type of debris flows and calculate the response interval of time. By the proper hazard mitigation processes, lives and properties can be saved under an effective monitoring system. The objective of this project is to monitor the occurrence and distribution of landslides for establishing a warning system of debris flows in a watershed. For realizing the context of debris flow disaster, the catastrophes of debris flows occurred in Chen-Eu-Lan creek basin would be collected and analyzed. Runoff hydrograph estimated from hydrologic data is going to be an index for studying the affecting factors of debris flow disaster. The changes of runoff hydrograph calculated from the model and from the measured data at the monitoring sites can be used for examining the occurrence and spatial distribution of landslide, which providing potential debris flow in the interested watershed.