黔中高原面石漠化演变典型案例研究——以普定后寨河地区为例

定量分析石漠化的演变过程,有助于客观认识石漠化、了解喀斯特石漠化的成因和开展石漠化的综合治理。选取位于黔中高原普定县境内的后寨河地区,基于1963年、1978年、2005年和2010年的高精度影像,研究了石漠化的演变过程和影响因素。结果发现,研究区1963年、1978年、2005年和2010年石漠化综合指数分别为1.5042、1.3311、1.2176和1.2376,说明研究区的退化石漠化总体上在恢复。1963-2010年,一直保持不变的石漠化占2010年石漠化的43.76%,15°~25°、>25°坡度范围内的强度石漠化比例基本保持不变,距聚落>900 m范围,强度石漠化的比例从1963年28.6%下降到2010年的10.6%。研究区石漠化广泛分布的中部10个村级单位不同土地利用类型的石漠化发生情况表明,各村陡坡耕地普遍发生严重的石漠化,较多坡耕地的存在仍是土地石漠化的驱动因素。

A typical case study on evolution of karst rocky desertification in Houzhaihe, Puding County, central Guizhou Province, China

Quantitative analysis of the evolution of karst rocky desertification(KRD)is useful to get a better understanding of the concept of KRD,the genesis of KRD and the measures of comprehensive treatment of KRD.In this paper,the evolution of KRD and influencing factors were studied based on high-precision images in 1963,1978,2005 and 2010,taking Houzhaihe area located on the central plateau of Guizhou Province as a study area.The results show that:in the study area,the comprehensive index of KRD was 1.5042,1.3311, 1.2176 and 1.2376 in 1963,1978,2005 and 2010 respectively,indicating that the land degradation of the study area is generally recovering.However,the area of unchanged KRD from 1963 to 2010 accounted for 43.76% of the total in 2010.The KRD with the slopes of 15°-25°and >25°was basically unchanged.Furthermore,within the area of distance>900 m away from the rural settlements,the percentage of severe KRD declined from 28.6% to 10.6% over the period 1963-2010.The KRD is mainly distributed in 10 village-level units of different types of KRD in the central part of the study area,indicating that commonly steep slope land was seriously desertified,and the existence of steep slope cropland is still one of the driving factors of land rocky desertification.