A seismically triggered landslide dam in Honshiyan, Yunnan, China: from emergency management to hydropower potential

Abstract

At 16:30 (Beijing time) on August 3rd, 2014, an Ms 6.5 earthquake occurred in Ludian County in Yunnan Province, China. The Ludian earthquake triggered a collapse in Chapingzi, right bank of the Niulanjiang River, and a landslide in Hongshiyan at the left bank on the same location. These events occurred 1.5 km downstream of the Hongshiyan hydropower station. Debris deposits from the collapse and the landslide blocked the river channel and formed a landslide dam. In this study, the Hongshiyan landslide dam induced by the Ludian earthquake was chosen as the study case to discuss integrated landslide dam management and its potential hydropower uses. After emergency management measures are carried out, further analysis shows the outflow through the Hongshiyan landslide dam is manageable, which indicate safety issues are controllable. Two management schemes are discussed in this paper: one that uses the Hongshiyan landslide dam for power generation and one that removes the debris deposit. The result shows that using the strengthened landslide dam for power generation is feasible and economically sound. This research estimate a capital recovery period of approximately 3 to 4 years with an investment-return ration of 1:40, which is considered a significant economic benefit.