中国典型石漠化地区土地利用与石漠化的关系

定量研究了贵州省盘县中南部峰丛洼地典型石漠化地区不同岩性的土地利用分布规律和不同土地利用类型的石漠化发生率.结果表明,难利用的、岩石裸露的石旮旯地在连续性石灰岩、石灰岩夹碎屑岩和石灰岩与白云岩互层分布区的比例很高.不同等级石漠化与不同土地利用类型和岩石类型存在着相关性,如坡耕地中以连续性石灰岩发生轻度石漠化的比例最高,其次是石灰岩碎屑岩互层分布区;研究区的轻度石漠化中,土地覆被以灌丛所占的比例最高,坡耕地占11.67%;中度石漠化中,土地覆被以中覆盖度草地所占比例最高;强度以上石漠化中,土地覆被以难利用地的石漠化比例最高.从1995到2000年,中覆盖度草地和难利用地中强度和极强度石漠化比例有所增加.基于上述研究,对研究区的石漠化土地覆被作了进一步的分类,指出了研究区的石漠化的形成过程和治理重点.

The Relationship of Land Use with Karst Rocky Desertification in a Typical Karst Area, China

Based on land rocky desertification and land use data (scale: 1:50000) in 2004, the distribution law of land use types with different lithologies and occurrence ratios of rocky desertification relating to different land use types in typical fengcong (peak cluster) rocky desertified area located in central-southern part of Panxian county of Guizhou province were researched quantitatively. The results indicate that there is a high ratio of difficult to use land with exposed basement rocks in homogenous limestone, limestone interbedded with clastic rock, mixed dolomite/limestone assemblages. There is relationship among different grades of rocky desertification and land use types and rock types, such as the cultivated land on slopes has a higher occurrence ratio of slight rocky desertification in homogenous limestone, and then the limestone interbedded with clastic rock. Slight rocky desertified land was dominated by shrub land, and sloping cropland accounts for 11.67%, moderate rocky desertification was dominated by moderate coverage grass slopes, intense rocky desertification was dominated by rocky dryland which is difficult to use. From 1995 to 2000, the rate of intense and highly intense rocky desertification in moderate coverage grass slopes and difficult to use land increased. Finally, the further classification of rocky desertified land by land cover was made according to the above-mentioned researches, and the forming processes and taming emphases of karst rocky desertification in the study area was also pointed out in this paper.