基于RS-GIS的长江三峡景观视觉敏感度模糊评价

RS-GIS Based Fuzzy Evaluation of Landscape Visual Sensitivity of Three Gorges of Yangtze River

利用长江三峡(重庆段)2002年Landsat ETM+和SPOT遥感影像解译资料,结合其他图文资料及现场调查数据,基于地理信息系统(GIS)技术建立了研究区域相关评价指标的空间属性数据库.利用模糊数学理论定义峡谷景观视觉敏感度各评价指标的模糊函数,并在GIS中利用地图几何代数(map algebra)求出单因子对各个级别的隶属度函数并建立每个栅格点的模糊关系矩阵.利用Delphi法建立各评价指标的权重集.通过GIS的栅格运算模块(grid caculator)对同一敏感级别的各个指标进行加权运算,得出每个栅格相对于各个级别的敏感度隶属度的综合指数,根据最大化原则确定每个栅格景观视觉敏感度级别.结果表明:①长江三峡(重庆段)景观视觉敏感度可分为4级,其中一级敏感区占区域总面积的2.38%;②景观视觉敏感度与观赏视距有较强的相关性;③评价结果与实际相符,知名度较高的景观具有高敏感度.最后根据评价结果提出了研究区域的景观规划、保护与管理的相应对策与建议.

Based on Landsat ETM^＋ and SPOT image taken in 2002, other chart or text information and field investigation, spatial attribute database for landscape evaluation indices in the Three Gorges of the Yangtze River （Chongqing Areas） of China is established with geographical information system （GIS） technique. The evaluation model of the landscape visual sensitivity of the valley is defined on the basis of fuzzy mathematics theory, the degrees of membership of each single index are obtained using map algebra of GIS, and fuzzy relationship matrix is set up for each grid as well. The weight value distribution set of evaluation indices is established by means of Delphi investigation procedure. In order to get a combined index representing the degree of membership of the various factors for each grid, weight-operation is conducted on each index of the specific sensitive level with GIS grid calculator, and then the landscape visual sensitivity is determined for each grid following the maximum principle. The results show that landscape visual sensitivity can be classified into four levels in Three Gorges of the Yangtze River （Chongqing Areas）, of which the first-sensitivity-level （the highest sensitive） area accounts for 2.38 % in the region; the landscape visual sensitivity is strongly related to the horizontal distance form a viewer; and generally, the well-known landscapes have higher landscape visual sensitivity. Finally, this paper presents mine strategies and measures for landscape protection, conservation management, and planning and design.