基于GIS与地理探测器的岩溶槽谷石漠化空间分布及驱动因素分析

岩溶区土地石漠化已成为中国西部继沙漠化和水土流失后的第三大生态问题,近年来岩溶槽谷区石漠化表现出增加趋势。通过获取槽谷区石漠化、岩性、坡度、海拔、降雨量、土地利用、人口密度和第一产业生产总值等数据,利用GIS空间分析功能和地理探测器模型,探讨了岩溶槽谷区石漠化空间分布特征及驱动因子。主要结论为：① 岩溶槽谷区总石漠化面积为21323.7 km ²,占研究区土地面积的8.3%,其中轻度、中度和重度石漠化面积分别是11894.8 km ²、8615.8 km ²和813.1 km ²,分别占石漠化面积的55.8%、40.4%和3.8%;② 从石漠化的空间分布来看,槽谷区石漠化主要发生在连续性灰岩中,轻度、中度和重度石漠化面积分别为占槽谷区相应石漠化类型面积的22.1%、22.4%和1.9%;槽谷区石漠化主要发生在15°~25°的坡度范围,轻度、中度和重度石漠化面积分别为占槽谷区相应石漠化类型面积的27.1%、18.2%和2.3%;从海拔来看,主要分布于400~800 m范围内,轻度、中度和重度石漠化面积分别为占槽谷区相应石漠化类型面积的24.9%、18.4%和0.2%;从土地利用类型来看,主要发生于山地旱地中;从人口密度来看,集中分布于100~200人/km ²中;从第一产业生产总值来看,集中分布于25亿~50亿元中;③ 地理探测器的因子探测器揭示了岩性（q = 0.58）、土地利用（q = 0.48）和坡度（q = 0.42）3个因子是槽谷区石漠化形成的主要驱动因子,交互式探测器进一步揭示了岩性与土地利用类型（q = 0.85）、坡度与土地利用类型的组合（q = 0.75）共同驱动槽谷区石漠化的形成。

Spatial distribution and driving factors of karst rocky desertification based on GIS and geodetectors

The rocky desertification in the karst area is becoming the third largest ecological problem in western China following desertification, as well as soil and water loss. In recent years, rocky desertification in the karst trough valley is increasing seriously, and puts more and more pressure on the environment. Therefore, by GIS spatial analysis functions and geodetector models, this paper aims to explore the spatial distribution of rocky desertification in different gradients and its driving factors based on rock desertification, lithology, slope, elevation, rainfall, land use, population density and the total output value of primary industry in the valley. The results are as follows: (1) The total rocky desertification area in the karst trough area is 21, 323.7 km ², accounting for 8.3% of the land area in the study area; of which the light, moderate and severe rocky desertification areas are 11, 894.8 km ², 8615.8 km ² and 813.1 km ², respectively, accounting for 55.8%, 40.4% and 3.8% of the desertified area. (2) From the spatial distribution, rocky desertification mainly occurs in the continuous limestone, and the light, moderate and severe rocky desertification areas respectively account for 22.1%, 22.4% and 1.9% of the corresponding rocky desertification types in the trough area; Rocky desertification in the trough area mainly occurs in the gradient range of 15° to 25°, and the light, moderate, and severe rocky desertification areas account for 27.1%, 18.2% and 2.3% of the corresponding rocky desertification in the trough area, respectively; From the elevation, it is mainly distributed in the range of 400-800 m, and the areas of rocky desertification with light, moderate, and severe erosion grades account for 24.9%, 18.4% and 0.2% of the corresponding rocky desertification area in the trough area, respectively; From the land use type, it mainly occurs in upland mountains; From the population density, it concentrates in areas with 100-200 persons/km ²; From the total output value of primary industry, it concentrates in areas with 2.5-50 billion. (3) The factor detectors of geographical detectors revealed that the lithology, land use, and slope are the main driving factors for the formation of rocky desertification in the trough region. Interactive detectors further revealed that the lithology and land use types (q = 0.85) together with slopes and land use types (q = 0.75) drive the formation of rocky desertification in the trough area.