Impact analysis of reservoir retirement:macro-processes and final effects

Retirement is a rational option for the reservoir dams with little rehabilitation values,but so far little attention has been paid to the impact analysis of reservoir retirement in China.A comparison between the reasons of reservoir retirement in China and those in US is conducted first of all,showing that the environmental-ecological consideration is not one of the most important reasons and neither one of the primary contents in retirement evaluation in China.It would probably result in very few measures to deal with the impacts,especially the environmental-ecological impacts induced by reservoir retirement.And then all the impacts are analyzed,including the developing processes of impacts and the corresponding final effects.The results show that all the other impacts are induced by runoff-sediment impacts and result in socio-economic impacts,and that all the impacts are site-specific,namely,the reservoir retirement has different impacts on the upstream,impoundment and downstream of the removed reservoir dams.Based on the above,a framework for impact evaluation is also presented,with the final evaluation results including economic effects and some social effects that could not be eliminated through economic measures.