Landscape Assessment on Impacts of the Hydroelectric Development in the Valley Region——Case Study of Nujiang River
峡谷区域水电开发景观影响评价——以怒江为例

The understanding of hydroelectric construction is becoming comprehensive from eco-environmental 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.