峡谷区域水电开发景观影响评价——以怒江为例

Landscape Assessment on Impacts of the Hydroelectric Development in the Valley Region——Case Study of Nujiang River

水电开发的环境影响评价近年来日益受到重视。景观影响评价是一个重要的内容。在简要阐述水电开发的景观影响评价的相关概念及意义之后,首先阐述了峡谷区域水电开发的景观影响及评价方法,然后以怒江为例,具体探讨了峡谷区域水电开发景观影响评价的过程与结果。通过设计一系列景观测度参数,包括可视域损失、大坝视觉影响范围、高差损失、景点改变、峡谷急流损失等,并利用GIS进行模拟,基于计算结果对水电建设对峡谷整体和局部景观影响以及坝址各段建库适宜性进行了评价。最后指出,在怒江这样的急流高山峡谷上建坝应该慎而又慎,其决策应参考包含景观影响评价在内的环境影响评价,并应逐步完善此方面的立法。

The understanding of hydroelectric construction is becoming comprehensive from ecoenvironmental and socio-economic perspectives. Positive influences occur on one hand and negative on the other hand. Hydroelectric development can cause great changes to valley landscape but landscape assessment on its impacts is weak in past studies. Many arguments have emerged concerning the planned 13 multilevel hydroelectric constructions in Nujiang River of China, called ＂the last natural big river in China without dams＂. These arguments have had impacts not only on the environment issues but also on the landscape ones, thus becoming extremely important. After briefly summarizing the significance and relative concepts of landscape impact assessment, this paper explores theories and methods at this point and designs a series of landscape impact assessment parameters such as the View Shed Loss, the Visual Disturbance Scope of dams, the Altitude Loss, the Sight Spots Loss and the Rush Flow Loss. Based on the concept of different levels of landscape impact of Nujiang River Valley, this paper classifies the landscape impacts into holistic and partial types, then utilizes GIS simulation and calculation of parameters to analyze alterations before and after the rising of water level for the whole valley and individual sites, and demonstrates the suitability of each dam site. Finally, this paper indicates that the hydroelectric power development in valley region such as Nujiang River should be especially circumspect, its decision-making should be based on comprehensive environmental impact assessment in which landscape assessment is included, and rigorous legislation also should be established gradually.