关键词: 澜沧江-湄公河, 水电梯级开发, 生态影响

Abstract: The Lancang-Mekong is one of the most famous international rivers in the world. It flows through six countries. There are plentiful hydraulic resources in the basin. Since the mid 1980s, as a main development subject, attention has been drawn to large scale damming and its effect on the environment. Hydropower investigation had been begun since the late 1950s in Lancang Jiang (the upper Mekong River). Hydropower cascade of 14 dams was planned in the early 1980s. At the end of the 1980s, planned as the key development area and hydropower development base in China, the alternative cascade of 8 dams has been chosen, in which, one had been finished, one is under construction and nearly finished, and two will be built soon. All these actions have caused the widely attention and been criticized in the world, but some of these criticisms are not true, especial for the Xiaowang dam, the highest dam in the world, which will be constructed by 2002. Based on 40 years’ hydrological data series, comparing the hydropower cascade indexes and simulated adjusting of the runoff, This paper draw up the conclusion as following: (1) The hydrawic resource concentrates in the mainstream in Lancang river and the tributaries in lower Mekong; (2) The sediment of the lower Mekong mainly comes from northern part of the Laos, not from Lancang river; (3) No essential harms to the sediment of the Lower Mekong and its delta area, if hydropower cascade developed on the Lancang mainstream; (4) The comprehensive countermeasures should be put into practice, so as to reduce the ecological impacts of hydropower cascade development: hydropower cascade focusing on the mainstream of Lancang and tributaries of the Lower Mekong, and canceling all cascades in lower Mekong, mainstream facilitating the integrated power network construction; It will meet the energy demand, reduce the cost, the inundated land, the residents and the harm to water environment. So it will benefit the irrigation development, flooding control, salt control, navigation, and ecological conservation the lower Mekong river basin.

Key words: Lancang Mekong River, hydropower cascade development, ecological impacts