石漠化景观格局分布特征及其影响因素分析——以贵州省盘县为例

The landscape pattern distribution of karst desertification and its influencing factors——A case in Panxian,Guizhou

以贵州省盘县2004年石漠化现状分布为基础，探讨石漠化斑块的空间组合格局类型及其影响因素。结果表明，该区石漠化景观呈现出极强度石漠化斑块集中分布型、强度石漠化与无石漠化斑块混合分布型、潜在石漠化与无石漠化为主分布型、轻中度石漠化聚集分布型和石漠化斑块相间分布型5种空间组合分布格局。人为干扰、自然因素是造成该区石漠化空间格局存在明显差异的主要原因。从全县来看，石漠化主要分布在坡度10°～17．5°的地带，其次是17．5°～35°的区域。从发生石漠化的土地类型来看，轻度石漠化主要分布于灌丛和坡耕地，中度石漠化主要分布于中覆盖草地和坡耕地，强度和极强度石漠化主要分布于中覆盖草地和来利用地。碳酸盐岩的分布、地形地貌和亚热带山地气候差异形成了不同的景观类型，而有限的土地资源和土地利用方式是控制喀斯特石漠化的主导因子。通过土地利用规模调整和优化，因地适宜实施退耕还林还草等，将有望实现强度、极强度石漠化景观逐渐向无石漠化景观的转变。

A case in Panxian, Guizhou is study to understand the spatial assembling of desertified karst landscape patterns and relevant influenced factors based on a landscape classification of ASTER images of Panxian county in 2004. It is shown that there are 5 pattern types including the mustering patterns of intense rocky desertification, the mixed patterns of intense rocky desertification and non-desertification, the pattern dominant by latent rocky desertification, the mustering patterns of light-middle rocky desertification and the random pattern of rocky desertification patches. These distribution patterns are formed by some disturbed conditions and environment factors, and have obvious spatial difference. In Panxian county, karst rocky desertification distribute mainly in the gradient range from 10° to 17.5°,secondly, the gradient range from 17. 5° to 35°; the major land-use types at light rocky desertification condition are shrubs and sloping cropland; the major land-use types at moderate rocky desertification condition are middle coverage grass land and sloping cropland; the major land use types at strong and extremely strong rocky desertification conditions is stony land that is difficult to use and middle coverage grass. Natural factors including the distribution of carbonate, karst geomorphology types and climate difference dominated by subtropical mountainous tridimensional climate come into being the difference of landscape, but limited land resources and its land-use and distribution are leading factors which control karst rocky desertifieation. Furthermore, ecological restoration such as the conversion of sloping field into forestland and grassland is an important process to alter karst rocky desertification patterns. Along with the adjustment and amelioration of land-use scale and pattern in Panxian, intense rocky desertification landscape will transform into non-rocky desertification landscape gradually.