Real-time landslide monitoring of Pubugou hydropower resettlement zone using continuous GPS

The rapid growth of hydropower in China raises concerns about the related resettlement issues. In order to obtain the real-time surface displacement data of the potential landslides, a continuous GPS observation network is established in new Hanyuan County where more than 100,000 people are resettled due to the Pubugou hydropower engineering in southwest China. GPS multi-antenna switch devices are used to reduce the hardware investment, and the results show that the RMSs of the two horizontal components are 2 and < 4 mm for the vertical component. This level of accuracy is comparable to the conventional "one antenna with one receiver" GPS observation mode. The comparison between the displacements evaluated by GPS monitoring method and digital inclinometer shows consistency, and this indicates that GPS could be a reliable complement to traditional ground movement monitoring methods. No catastrophic landslide failures happened since the resettlement was completed. We captured a remarkable movement in August 2011, and this proves that the continuous GPS monitoring system could be used to detect early indications of rapid displacement and for disaster warning.