MONITORING AND TREND PREDICTION OF RESERVOIR-INDUCED SEISMICITY IN HU'NANZHEN HYDROPOWER STATION

摘要

The Wuxi River, a tributary of the Qiantang River, is located in the Zhejiang Province. The cascade development of the Wuxi River consists of two separate hydropower stations, which have a total designed capacity of 352 MW. The upper one is called the Hunanzhen Hydropower station. The Hunanzhen dam is 129 m high, which is the highest concrete trapezoid dam in Asia. The drainage area above the dam site is 2197 km. The storage is 2.06 × 109 cm~3, and the normal water level is 230.0 m. The Hunanzhen reservoir began to store water on January 12, 1979. In May of that year, a felt earthquake occurred 16 km away from the dam. On October 7, a reservoir-induced earthquake measuring ML 3.4 took place. Then there were a number of very slight shocks with earthquake sounds. Based on primary statistics, 8000 earthquakes occurred in the reservoir area and now there are still some weak seismicity.