贵州连续性碳酸盐岩上覆景观特征的定量研究

利用GIS软件,探讨了贵州以连续性碳酸盐岩为基底地区的上覆景观单元、破碎化及斑块分形的特征及其形成原因。研究区域中,受岩性控制景现在整体上体现出一致性的基础上,又存在着明显的内部差异性。一致性表现为以灌木林地为优势景观,森林和草地中以次生景观为主,偏小的斑块占大多数,斑块大小分布全为正偏, 其分布曲线多为尖峭峰,斑块研究不存在面积上尺度域,斑块形状在人为强烈干扰下趋于规则而导致类型分维数的值偏小,人为干扰大的景观中斑块的破碎化更加明显。相比连续性白云岩地区,连续性石灰岩地区的水资源利用率低下,抗干扰能力弱,景观多样性不均衡,退化更严重,分割程度更破碎,空间异质性更强,稳定性差,易向逆向演替的方向发展。

QUANTITATIVE STUDY OF LANDSCAPE PATTERNS IN HOMOGENOUS CARBONATE ROCK-DISTRIBUTED REGIONS IN GUIZHOU

With the utilization of GIS software, research is conducted on a) the characteristics of cells, fragmentation, and patch fractal of landscape based on homogenous carbonate rocks in Guizhou; and b) causes of the formation of these characteristics. It has been found that under the influence of lithology, the landscape of the study region as a whole shows consistency, yet embodies distinct diversity inside. The consistency is embodied in the following aspects; a) the preponderant landscape consists of bushes and small woods; b) secondary landscape is characteristic of forests and grass grounds; c) of all the patches making up the study area, small patches are dominant, with positive-skewed distribution of patches-as a result, steep peaks are characteristic of the charts showing the distribution of patches. The factor of scale is not taken into account in the study of patches. The shapes of patches tend to become regular with strong disturbances from human activities, and consequently, the values of fractal dimensions of landscape types tend to get smaller. The fragmentation of patches is more apparent in landscape under the influence of human activities than the one without these disturbances. Compared with regions characteristic of homogenous dolomite, the characteristics of homogenous limestone areas are presented in the following: a) low utilization rate of water resource; b) uneven distribution of diversified landscape; c) weak resistance against disturbances from human activities; and d) continuous degradation, ever-increasing fragmentation, intensification of spatial heterogeneity, and deteriorating stability of landscape. All the above characteristics make homogenous limestone areas develop in reversed succession.