三峡库区(重庆段)地表起伏度及其对生态系统服务价值的影响

Surface Relief Degree and Its Effects on Ecosystem Service Value in the Chongqing Section of the Three Gorges Reservoir Region,China

地表起伏度与生态系统服务价值密切相关。地表起伏度决定或直接影响土地利用类型,造成不同地表起伏度地区生态系统服务价值不同。利用ASTER GDEM V2全球数字高程模型数据,通过窗口分析法获得三峡库区(重庆段)地表起伏度。利用土地利用数据,参照中国陆地生态系统单位面积生态服务价值当量表,计算三峡库区(重庆段)生态系统服务价值,定量分析地表起伏度与生态系统服务价值的相关性。结果表明:(1)研究区地貌复杂,地表起伏较大,整体来说东部高于西部,其中地表起伏度最大的是巫溪(1.360 3),最小的是渝中(0.289 0)。(2)研究区人均生态系统服务价值空间分布不均,东部为天然林保护区和水源涵养区,人均生态系统服务价值高。西部为都市重点开发区和城市发展新区,人均生态系统服务价值低。(3)地表起伏度与人均生态系统服务价值呈正相关,对其影响程度由大到小依次为原材料生产、食物生产、气体调节、气候调节、价值总量、水文调节、保持土壤、提供美学景观、维持生物多样性和废物处理。研究表明,加强对位于高地表起伏度区的天然林保护区和水源涵养区的保护是维护和提高库区生态系统服务价值的有效途径。

Relief degree of ground surface （ RDGS） is closely related to magnitude of the ground surface and hence to land use patterns,which consequently affects service value of the ecosystem in the region. The objective of the study is to examine effect of RDGS on ecosystem service value in the Chongqing Section of the Three Gorges Reservoir Region, China. The ASTER GDEM V2 dataset was used to extract RDGS of the region by means of window analysis. Based on the land use data available,ecosystem service value in the section was worked out using Costanza^s method and the modified ecosystem service value coefficients. Then correlation between the RDGS and land ecosystem services value was quantitatively analyzed. Results show that： （ 1） The landform is complicated and the RDGS varies sharply in the region. As a whole, RDGS is higher in the east than that in the west,and the highest in Wuxi （ 1. 360 3）,and the lowest in Yuzhong（ 0. 289 0）. （ 2） Per capita ecosystem service value distributed unevenly in space. The value is high in the eastern part, for it is com-posed of natural forest reserves and water conservation and low in the western part, for it consists mainly of key development zones of cities and new urban development areas. （ 3） A positive relationship is observed between RDGS and per capita ecosystem service values. In terms of effect of RDGS on ecosystem service values, the services display a decreasing order of raw material production〉food production〉gas regulation〉climate regulation〉total value〉 hydrological regulation〉 soil conservation〉provision of aesthetic landscape〉maintenance of biodiversity〉waste disposal. The study reveals that strengthening the protection of natural forest reserves and water conservation zones in the areas high in RDGS is an effective way to protect and improve the ecosystem service values in the Three Gorges Reservoir Region.