石漠化斑块动态行为特征与分类评价

对石漠化土地的特征进行全面深入的探讨，有助于石漠化土地分类治理和生态恢复重建。本文以SPOT5影像(分辨率2.5m)和航片(空间分辨率1m)为基本数据源，辅以实地踏勘和农户访问，通过跟踪每个石漠化斑块在2个时段的演变关系，研究了贵州清镇簸箩村1973-2005年石漠化斑块的新增(延展、新生)、消融和未变等动态变化特征。结果发现轻度石漠化土地斑块与其他石漠化类型在空间上存在着强烈的转换，相互之间的频繁转换使斑块具有不稳定性而处于一种波动状态。从各类石漠化斑块的来源看，存在一些斑块由无石漠化直接到极强度石漠化斑块之间的转换。根据石漠化斑块的动态演替行为认为,可将研究区2005年的石漠化分为未变石漠化、新生石漠化、延展石漠化，并据此提出石漠化强度指数和石漠化的治理对策。

Dynamic Behavior Characteristics and Classification Assessment of Karst Rocky Desertification

It is beneficial to probe into the characteristics of karst rocky desertification land for the taming of different types of lands with karst rocky desertification (KRD) problems and the ecological restoration and recon-struction of lands with rocky desertification. Remotely sensing data such as SPOT 5 images (resolution at 2.5 m) and aerial images (scale: 1:50000), integrating with the field and household investigation, were used to carry out a study on patch evolution types of KRD from 1973 to 2005 in Boluo catchments of Qingzhen, Guizhou Province, a typical karst area in Southwest China. Three evolution types of KRD patches, i. e., newly generated, expanding, dissolved and not changed were distinguished. The results show that the mutual transformation of slight KRD to moderate KRD, strong KRD and extremely strong KRD was extremely remarkable during the pe-riod 1973-2005, demonstrating that the KRD patches had been in a unstable fluctuation status. However, there were some evolutions from no KRD patches to the high rank of KRD patches according to the origin of patches. The karst rocky desertification land in the study area could be classified into unchanged KRD, newly generated KRD and expanding KRD, from the viewpoint of dynamic behavior characteristics of patches, furthermore, the intensity index of KRD and some suggestions to prevent and tame KRD were put forward.