喀斯特高原峡谷与高原盆地区石漠化及变化特征对比

Comparative Study on Rocky Desertification between Karst Gorge and Plateau Basin Area

以贵州典型喀斯特峡谷和高原盆地区为研究对象,以5期卫星遥感影像为数据源,综合运用"3S"技术,辅以其他参考图件获得研究区不同时段石漠化图,通过对研究区石漠化状况及工程治理后动态变化特征作对比分析,探讨不同地貌类型区石漠化及其变化特征的差异性。研究表明:石漠化发生与演变和地貌类型存在一定相关性,花江喀斯特峡谷区和清镇喀斯特高原盆地区石漠化发生率分别为67.4%和31.6%,花江喀斯特峡谷区石漠化面积、石漠化发生率、石漠化强度明显地高于清镇高原盆地区。2000―2010年,花江喀斯特高原峡谷区和清镇喀斯特高原盆地区石漠化面积分别减少2.79和5.04 km2,石漠化年变化率分别为-0.91%和-2.78%,清镇喀斯特高原盆地区石漠化减少更明显。在监测时段内,花江喀斯特高原峡谷区石漠化年变化率先增加后逐渐减少,而清镇喀斯特高原盆地区则一直保持较高的石漠化年变化率,这在一定程度上说明石漠化越严重,治理越难,治理成效越不明显。当前开展的石漠化治理专项工程应根据不同地貌类型差异合理布设治理工程,先易后难,重点做好轻、中度石漠化地区的石漠化治理工作。

The paper takes typical karst valleys and plateau basin areas of Guizhou as the research objects. Using the remote sensing images of five periods as the data source, the paper interprets the rocky desertification maps of each research area in different periods with the support of“3S”technology and other reference maps, and through dynamic monitoring of rocky desertification in different treatment stages, explores the diversity of rocky desertification distribution and variation in different geomorphic areas. The results show that： there were significant correlation between topography and rocky desertification, the incidence of rocky desertification were 67.4% and 31.6% in Huajiang gorge area and the rocky desertification area in Qingzhen plateau basin, respectively, the occurrence rate, rocky desertification intensity in Huajiang karst gorge area were higher than those in Qingzhen plateau basin. From 2000 to 2010, in Huajiang karst gorge rocky desertification area reduced 2.79 km2, annual variance ratio of rocky desertification was -0.91%, while in Qingzhen plateau basin rocky desertification area reduced 5.04 km2, annual variance ratio was-2.78%. The change of rocky desertification was more obvious in Qingzhen plateau basin areas. In the monitoring period, annual variance ratio of rocky desertification in Huajiang gorge area gradually reduced after the first increase, while Qingzhen karst plateau basin maintained a high decreasing rate. Those to a certain extent indicated that the more serious the rocky desertification was, the smaller the treatment effect would be, and the more difficult the engineering control would have. For controlling current rocky desertification, at present the comprehensive treatment project should pay more attention to lighter intensity areas, where further aggravation of rocky desertification should be prevented, as it would make the desertification control become more difficult.