三峡成库前后沿江山水景观空间视觉特征比较

A Comparative Study of the Hills and Water Landscape Visual Features along the River Before and After the Reservoir Construction in Three Gorges

以景观空间尺度规律与人的视觉规律为指导,基于RS、GIS以及AutoCAD技术,从江面视点出发,通过测定山水景观视觉空间断面的宽高比,辨识长江三峡库区(重庆段)沿江山水景观视觉空间的类型.从空间视域、视距与观景者视觉接收后所产生的心理体验等几个方面,比较分析了长江在三峡成库前的常年洪水位、成库后的145与175 m水位下沿江景观视觉特征的变化.结果表明:①沿江山水构建出夹景、敞景、框景3种视觉空间类型;②长江水位的抬升对沿江山水景观视觉空间的总体特征影响不大,整体山水景观空间格局不变,夹景空间峡感犹存,雄、奇、幽的三峡风貌基本不变,但高峡平湖景观取代滩多水急的风光,两岸支流可达性增强,消落带由夏水冬陆型转为冬水夏陆型.对此提出了相应的景观规划与建设的对策建议,以期对三峡工程的景观视觉质量影响评价及景观规划建设提供科学依据.

On the basis of a guidance of the landscape spatial scales principles and visual patterns, based on RS/GIS/AUTOCAD technology, this paper identified the type of landscape visual space in Three Gorges reservoir area （Chongqing） by calculating the value of D ： H of the biggest natural landscape space flood. In the aspects of viewshed, and the view distance as well as psychological experience of the viewer , the paper analyzed comparatively the changes in the landscape visual features of the comprehensive natural landscape space under the different water levels （145 m, 175 m）of Yangtze River before and after the reservoir construction in Three Gorges. The results show that （1） There are three types of landscape visual space： vista liner landscape, open landscape and framed landscape; （2） The water level of Yangtze River would have little impact on the comprehensive natural visual space： the overall landscape visual pattern will not changed, the overall features of canyon space would be still protected there. The features of Three Gorges ,such as majesty, oddity and quiet, will basically not change. The former more beaches and speeding flow will be replaced by alpine valley and flat lake landscape, it will be easy to go to the small branches,the water-level-fluctuating zone will be changed from a type of summer water and winter land to a type of winter water and summer land. Some strategies were presented for the landscape planning and construction in order to provide a scientific basis for Three Gorges Project.