贵州省石漠化敏感性的动态演变与模拟预测

The Dynamic Change and Simulation and Prediction of Sensitivity ofthe Karst Rocky Desertification of Guizhou

石漠化敏感性评价是为了识别容易发生石漠化的区域,评价石漠化对人类活动的敏感程度。石漠化敏感性评价应根据石漠化问题的形成机制,分析石漠化敏感性的区域分异规律,明确石漠化问题可能发生的地区范围与可能程度。在遥感和地理信息系统的支持下,利用贵州省1:50000地形图和2000年的TM影像,结合贵州省水文地质图,土壤图,地质地貌图,岩组图,政区图以及其他的地理基础信息为数据源,得到贵州省1962年和2000年的石漠化的敏感度数据,确定相应的状态转移矩阵,应用马尔科夫过程模拟石漠化敏感度的动态演变过程和未来演变趋势。研究表明:在贵州省各石漠化敏感类型中,只有不敏感类型面积在下降,从1962年占国土面积的61.35%变化到2000年占国土面积的55.55%,变化幅度最大,同时各石漠化敏感度类型之间相互转换,面积增加幅度最大的是中度敏感类型。预测表明:在未来几十年中,贵州省不敏感地区面积呈明显下降趋势,中度敏感类型面积呈明显上升趋势,轻度敏感类型面积变化基本趋于平稳,而高度敏感类型和极敏感类型面积都有小幅度上升,说明贵州省石漠化危险程度在加剧。

The sensitivity evaluation of rocky desertification is for the purpose of the recognition of the region which is liable to cause rocky desertification and evaluating the sensitive degree of rocky desertification upon human activities. And it is to analyze the regional distributive laws of the sensitivity of rocky desertification and explicit the regional area which is liable to cause and the possible degree according to the formation mechanism of rocky desertification. Using the 1：50000 relief map and TM images of Guizhou in 2000, combined with GIS and RS technologies, the sensitivity data of the Karst Rocky Desertifieation （KRD） of Guizhou Province in 1962 and 2000 was obtained. The dynamic evolution process and development trend were simulated using markov model. The results show that of all the sensitivity types of KRD in Guizhou, the area of non-sensitivity decreased from 61.35% of that of Guizhou in 1962 to 55.55% of that in 2000, and it had the largest change range. Furthermore, there was mutual conversion between all the sensitivity types of KRD and the area increased most is that of moderate-sensitivity. The prediction shows that in the future the area of non-sensitivity will reduce significantly, while that of moderate-sensitivity will increase; and the area of light-sensitivity will approach equilibrium while that of highly-sensitivity and extreme-sensitivity will rise in low amplitude. And it indicates that the risk level of the KRD of Guizhou is aggravating.