An estimation of ecological risk after dam construction in LRGR, China: Changes on heavy metal pollution and plant distribution

Dam construction has become one of the most controversial and wide-debated issues these days, mainly due to the unanticipated ecological risk it brings to river basin. Though the environmental impact caused by dam project has been reported in considerable literatures, most of them were concerned with the condition of aquatic ecosystem (e.g., hydrology, water quality, sediment, and aquatic fauna) with the potential risk of terrestrial ecosystem remaining unsettled. This study estimated the ecological risk on terrestrial ecosystem after dam construction by focusing on the heavy metal pollution and distribution of plant community in Lancang River of LRGR. The heavy metals were determined, and the plants were investigated in the reservoir and downstream of three dams built on the river. The results showed that notable changes had taken place in both objects, which indicated the existence of ecological risk on river ecosystem. This study might serve as the first step of computing dam-induced risk in wholeecosystem scale.