黄河拉西瓦水电站建设对区域景观格局的影响

本根据水利水电工程对景观格局的影响特征,从拼块类型尺度和景观尺度选出优势度、多样性、均匀度、分离度等8个能全面反映景观格局变化的数量化指数,完善了水利水电工程环境影响评价内容。以黄河拉西瓦水电站为例,对该区域LandsatTM7图像解译和GIS处理,结合工程设计规划,绘制建设前后区域景观格局图,建立空间信息数据库,计算各景观指数,分析其变化趋势。结果表明,黄河拉西瓦水电站区域有16种景观类型,分别属于6种生态系统,拼块类型多样,景观格局复杂,其中草地景观优势度最高,接近80％;建成后拼块类型的景观比例、密度、优势度、分离度等都有一定变化;景观均匀度、多样性指数和人为干扰强度都相应增加。总体上,景观格局没有发生大的变化,区域生态系统的功能和性质也不会改变。

IMPACTS ON REGIONAL LANDSCAPE PATTERNS OF HUANGHE LAXIWA HYDROELECTRIC STATION

As is known, water conservation and hydropower projects may influence the regional landscape to some extent. The present article aims at presenting a quantitative and qualitative analysis of the impact of the construction of Laxiwa Hydroelectric Station on the local landscape. Laxiwa Hydroelectric Station is located at the outlet of Longyang Gorge along the Yellow River, 134 km away from Xining, the provincial capital of Qinghai. The project will be the largest hydropower Station in the Yellow River Basin with 5,600 MW installed power generating capacity. When built up, it will assume the role of "west power being transmitted to the east". However, this paper mainly focuses on the assessment of its eco environmental impact. First of all, from the point of view, the Land TM7 remote sensing image and the project of map planning, the landscape pattern maps before and after the hydropower station construction, RS and GIS technologies and the landscape pattern will be changed. That is, (1) the change with the area's 16 landscape types, belonging respectively to six categories of the eco system, featured by the predominant grassland (79.22% and 79.06%) of the area; (2) the change with its landscape patch scale, density, seclusion, tranquility, and so on;(3) the increased disturbance of landscape evenness, diversity and human disturbance indices after its construction. And, finally, two problems as to the landscape feature assessment of the area are discussed in the paper: (1)the assessment of the area choice, for the appropriate local feature decides its indices the landscape values; (2)the assessment of the buffer zone of human activity influence and the buffer zone problems should be involved in most.