三峡库区开县蓄水前后景观格局变化特征

Changes of landscape pattern and its characteristics in Kaixian county before and after impoundment of Three Gorges Dam Project

三峡工程是世界上举世瞩目的大型水电水利工程,其建成后具有巨大的综合效益,但水库蓄水完成后,也引起库区内的土地覆被与景观格局的变化。为了及时掌握水库蓄水后库区土地覆被及景观格局变化情况,该文以三峡库区重庆市开县为研究对象,基于2002、2007和2010年3期遥感影像资料,运用遥感与GIS技术和景观格局分析方法,利用ArcGIS9.3、Ecognition8.0、Fragstats3.3等软件分析了研究区土地覆被与景观格局动态变化特征。研究表明:由于受2002-2010年间水库蓄水影响,开县土地覆被与景观格局均有剧烈变化。该地区景观优势类型是森林、灌木、旱地、草地和水田。景观类型水平上,旱地、水田、草地景观面积减少且破碎度增加,但森林、水体、建设用地面积增加,同时连通性增加;景观格局水平上,景观总体破碎度增加,景观优势度降低,但景观多样性增加,有利于该地区生态系统稳定。开县2002-2007年和2007-2010年2期景观格局变化表现出不同的特征。研究结果及时反应了水库蓄水前后的土地覆被与景观格局变化特征,为水库未来土地利用合理规划与生态景观设计提供依据。

The Three Gorges Project is a remarkable large-scale hydropower and water resources in the world. The project will bring great comprehensive benefits after the completion. However, as the reservoir storage completing, it also caused land cover and landscape pattern changes in this area. In order to grasp the changes of land cover and landscape pattern after the reservoir water storage, Kaixian county of Chongqing city in Three Gorges reservoir area was taken as the research object in this paper. Based on 2002, 2007 and 2010＇s three remote sensing image data, and using remote sensing, GIS and landscape pattern analysis techniques, the dynamic changes of land cover and landscape pattern was analyzed with the professional software such as ArcGIS9.3, Ecognition8.0 and Fragstats3.3. The results showed that Kaixian＇s land cover and landscape pattern changed dramatically due to the effects of reservoir storage during 2002 to 2010. The dominant types of landscape in the region were forest, bush, dry land, grassland and paddy field. On the Class Level, the area of dry land, paddy fields and grassland had decreased, and landscape had increased. While the area of forest, water, construction land had increased, and the fragmentation of the connectivity increased too. On the Landscape Level, the landscape fragmentation had increased, and landscape dominance had decreased, but the landscape diversity had increased, which was beneficial to stability of the ecosystem in the region. It showed that different characteristics of Kaixian＇s landscape pattern changed during 2002-2007 and 2007-2010. The results timely respond the character of land cover and landscape pattern＇s changes before and after impoundment. This paper provides the basis for land use of the reservoir planning and ecological landscape design.