水利工程梯级开发对河流生态系统服务累积影响浅析——以猫跳河为例

Cumulative Effects of Cascade Hydropower Development on River Ecosystem Services: A Case Study of the Maotiaohe River

水库的梯级建设对河流生态系统服务的影响具有空间和时间上的累积作用,既有正面效应,也有负面效应。在提供产品方面,水利工程梯级开发提高了猫跳河的供水、供电能力。随着人类的调整,不同时间提供的产品种类有所侧重。在休闲娱乐方面,红枫湖和百花湖建设初期,旅游业大肆发展,但是随着污染的加剧和水库功能的调整,两大湖的旅游业已经凋败。调节环境方面,水库在调蓄洪水和调节大气组成方面有重大的正面效应,但是由于河流径流的改变,水库的建设大大减弱了河流的自净能力。在支持生命方面,水库的梯级修建,改变了天然河道,使得猫跳河流域丧失了一些物种的生境,生物多样性较同等条件天然生境低。

Cascade development of hydropower projects has cumulative effects on river ecosystem services on both time and space scales, which are different from the single project. Some of these influences are positive, while the others are negative. Analysis and assessment of the impacts of the cascade hydropower projects on river ecosystem services are helpful to guide reasonable development of hydropower in the future. The Maotiaohe River is one of the earliest extensively exploited rivers in Guizhou Province, southwestern China, on which hydropower projects were initialized in the 1950s and completed in the 1970s. There have been totally 7 dams on the river. By a semi-quantitative analysis, it was found that there were differing impacts of the hydropower projects on ecosystem services of the Maotiaohe River over the nearly 50 years. The 7 dams showed a positive effect on the products supply service of the river, such as the supply of hydropower and the increase of the water supply. As pollution of the river environment increased and actions to abate the pollution were taken, the type and number of products supplied by the river have been changed. For example, the main function of Hongfeng Lake and Baihua Lake was changed from flood control and power generation at first to water supply to cities at present. As to the entertainment function of the river, the tourism was prosperous at the time when Hongfeng Lake and Baihua Lake were initially made. However, the tourism has been at low ebb due in part to the pollution caused by economic development and the adjustment of the main function of the two lakes by human. As to the environment adjustment function of the river, the dams on the Maotiaohe River played an important role in flood control and water storage and reducing CO2 emission, SO2 emission, NOX emission, and dust emission to the atmosphere caused by fired power plants alternatively. However, the capacity of self-purification of the river was declined greatly because of changes in the runoff and the shortening of the purifying distance of polluted water in the river. Regarding the life sustention service, the hydropower projects on the Maotiaohe River have changed habitats of certain flora and fauna, which has resulted in decreased biodiversity in the Maotiaohe River watershed. In Hongfeng Lake and Baihua Lake, the type and number of wading birds were less than the lake of the same type of natural conditions in Caohai in Guizhou Province