石漠化景观生态优化途径初探——以贵州清镇王家寨小流域为例

以治理石漠化、维护喀斯特景观生态安全和土地资源的可持续利用为目标,以景观生态学理论为指导,选择西南典型喀斯特石漠化地区——贵州清镇王家寨流域为研究区,并建立了源于最小累计阻力模型的生态恢复耗费表面模型,其步骤如下:首先以2005年SPOT影像为基础,依托遥感和地理信息系统软件,对研究区土地类型进行分类,同时从数字高程模型中提取两种地形因子(坡度和坡向),并按其对生态的影响进行分级;其次对土地利用类型、坡度、坡向进行综合优先级评价;最后在IDRISI软件中建立生态恢复耗费表面模型。随后通过景观功能分区和生态廊道(这些廊道可组成一个生态网络)的构建,探讨了本小流域土地利用空间格局优化的途径和生态恢复模式。

Study on optimization of landscape ecology in karst rocky desert-A case study in Wangjiazhai catchments, Qingzhen, Guizhou

Aiming at management of karst rocky desertification,maintenance of the security of karst landscape ecology and sustainable use of regional land resources; under the guide of landscape ecology theory; taking Wangjiazhai catchments, a typical karst area in Southwest of China as a case, an accessibility surface of ecological restoration model which stems from minimum cumulative resistance (MCR) is constructed in this paper with the following processes: firstly, based on the image of SPOT5 in 2005, with the support of GIS and RS software, land use types in the study area are classified, and two terrain factors (slope gradient and slope aspect) are derived at the same time from the digital elevation model and graded according to ecological effects; secondly, priority order is evaluated on the basis of different land use types, slope gradient and slope aspect; thirdly, source's terrain are selected; and finally, accessibility surface of ecological restoration model is constructed in IDRISI. Then, on the basis of functional division to the landscape and construction of ecologic passage, the optimization of land use spatial pattern and the mode of ecological restoration on catchments scale are approached in the paper.