根据三峡工程对河流生态系统服务功能影响的特点,建立了评价指标体系,预评估了三峡工程全面竣工正常运行后,对河流生态系统服务功能的6项正面影响和5项负面影响。结果表明,防洪和发电是三峡工程的主要功能,年功能价值分别为106.84×108元和211.70×108元;旅游、减少有害气体排放、改善川江航道和水库养殖也是三峡工程的重要功能;6项正面影响的年功能价值总计489.70×108元。库区污染、泥沙淤积和水库淹没是三峡工程的主要负面影响,年损失值分别为24.06×108、7.22×108和6.27×108元;对生物的影响和对河流生态系统的占据,也是不容忽视的负面影响;5项负面影响的年功能损失值总计37.83×108元。

The accurate valuation of effects of hydraulic engineering on river ecosystem services is very important to Environmental Impact Assessment(EIA)of hydraulic engineering and the reserve river ecosystem services.On the basis of the effects features,an index system for the assessment of effects of the Three Gorges Project(TGP)on river ecosystem services has been established.The six positive effects and five negative effects were pre-evaluated when TGP was finished.The result indicated that flood control and hydropower generation were the main functions,with annual values being 106.84×108yuan(RMB)and 211.70×108yuan,respectively.Tourism,harmful gas emission reduction and navigation channel improvement were importance functions of TGP,too.Their annual values were 74.50×108yuan,79.44×108yuan,and 14.64×108yuan.The annual values of the six positive effects were 489.70×108yuan.The reservoir contamination,reservoir sedimentation and reservoir flowage by TGP were the main negative effects,and the annual losses were 24.06×108yuan,7.22×108yuan and 6.27×108yuan separately.At the same time,the effects of TGP on biological factors and occupation of river ecosystem were also negative effects,which couldn't be ignored and the annual losses were 0.27×108yuan and 0.01×108yuan respectively.The annual losses of the five negative effects totalled 37.83×108yuan.The researches show that EIA of the large hydraulic engineering was not only done on single factor evaluation,but more attention was also given to effects of engineering on river ecosystem health and river ecosystem services.