喀斯特石漠化与土地利用相关性研究

The Correlation Analysis of Desertification of Karst Rock and Land Use Patterns

基于黄平县2004年的石漠化和土地利用数据,定量研究了黄平县各区不同等级石漠化土地中土地利用类型的分布规律和不同土地利用类型的石漠化发生率。结果表明,不同等级石漠化与不同土地利用类型存在着相关性,石漠化土地中以灌木林地、低覆盖度草地、未利用地、山区旱地、石质旱地等土地利用类型占较大比例。轻度石漠化土地中以低覆盖度草坡和中密度草坡为主,中度石漠化土地以未利用地和低、中覆盖度草坡和石质旱地为主,强度石漠化土地以石质旱地和未利用地为主。灌木林地中中度石漠化最高可占4.17%,低覆盖度草地中轻度石漠化比例最高为62.09%,未利用地中中度石漠化比例最高可达56.95%、强度石漠化比例可达5.43%,山区旱地中中度石漠化比例可达5.21%,石质旱地中中度石漠化比例可达56.78%。在研究区,土地利用和石漠化的这种空间关联因区域而异,土地利用和石漠化的相关性受岩性等因子的控制,在岩性以连续性白云岩为主的区域,石漠化发生比例大于研究区其它岩类,连续性白云岩区存在的大面积草山草坡均以已发生不同程度的石漠化。

Based on data of Karst land desertification and land use in 2004 （scale： 1：50 000）, the law of distribution of Karst land are revealed and occurrence ratio of rocky land desertification in Huangping county are explored quantitatively. Results indicate that there is a correlation between different grade rocky desertification and land use types. The shrub land, sparsely covered grass slopes, unused land, slope cropland and rocky dryland have a higher occurrence ratio of karst rocky desertification. Slight rocky desertification occurs in sparse and moderate coverage grass slopes; moderate rocky desertification occurs in unused land and moderate coverage grass slopes and rocky dry land; intense rocky desertification occurs in rocky dry land and unused land. The rate of occurrence of moderate rocky desertification is 4.17 % in shrub-land; the rate of slight rocky desertification is 62.09 % in sparse coverage grass slopes; the rate of moderate rocky desertification is 56.95 % and the rate of intense rocky desertification is 5.43 % in unused land; the rate of moderate rocky desertification is 5.21% in slope cropland ; and in rocky dry- land the proportion of moderate rocky desertification is 56.78 %. In study area, these correlations between land use pattern and different grade rocky desertification varies with districts and are affected by such factors as category of rock. In the lithology and dolomite dominated area, the occurrence ratio of rocky desertification is greater than others. Large area of grass hills with dolomite distribution has taken place rocky desertification in various degrees.