近30年来粤北岩溶山区石漠化土地景观动态分析

Landscape Dynamics of Rocky Desertificated Lands in Karst Mountainous Region of North Guangdong in Recent 30 Years

在野外调查的基础上,对粤北岩溶山区进行了不同时期卫星影像的解译和制图,分析了近30年来该地区石漠化土地的景观动态与格局变化。结果表明:近30年来,粤北石漠化景观呈逆转趋势,研究区石漠化土地面积持续减少,1974年石漠化土地面积为2042.43 km2,占喀斯特分布区的42.47%,1988年与2004年分别下降至33.95%和21.14%;轻度石漠化土地面积减少速度最快,至2004年中度石漠化土地取代轻度石漠化土地成为分布面积最广的石漠化类型;研究区景观异质性持续降低,潜在石漠化土地面积不断增加,景观连接度升高;石漠化土地斑块密度增大但平均斑块面积减小,斑块趋于均匀。

Based on remote sensing images in Karst area of north Guangdong in 1974, 1988 and 2004 and the field investigation, three landscape maps of the Karst mountainous region in north Guangdong were produced. In recent 30 years, the rocky desertification in north Guangdong is experiencing a reverse process. The area of rocky desertification lands in 1974 was 2 042.43 km^2, covering 42.47% of the Karst region in study area. In 1988 and 2004, the ratios of rocky desertification lands reduced to 33. 95% and 21. 14% respectively. Slight rocky desertification land had the fastest decrease speed in the past 30 years among the different degradation degrees of rocky desertification lands, and in 2004 the moderate rocky desertification land appeared to have the largest proportion. The landscape heterogeneity of Karst region depressed continuously, and the landscape connectivity enhanced. The patch density of rocky desertification lands increased but the mean patch area decreased. The area of patches of rocky desertification lands has tended to be even.