基于AHP与改进型MEDALUS模型耦合的科尔沁沙地土地沙漠化敏感性综合评价

Comprehensive evaluation of land desertification sensitivity in the Horqin Sandy Land based on the coupling of AHP and improved MEDALUS model

科尔沁沙地是“三北”防护林工程的重要区域,开展区内沙漠化研究具有特殊的必要性和紧迫性。本研究创新性地引入层次分析法(AHP),筛选与优化地中海荒漠化和土地利用模型(MEDALUS)因子,构建新的土地沙漠化敏感性评价指标体系,综合考虑气候、土壤、植被、土地管理和社会经济5个方面的指标来评估科尔沁沙地土地沙漠化敏感性。在此基础上,引入地理探测器模型对科尔沁沙地土地沙漠化敏感性空间分异的影响因素进行了探讨。结果表明:(1)土地沙漠化敏感性评价指标体系中植被质量指数权重最高,为0.4624,其次为气候和土壤质量指数。(2)科尔沁沙地沙漠化敏感区域占研究区总面积的78.22%,受沙漠化影响的敏感区域范围较广;极敏感和高度敏感区所占比重虽然较小(8.77%),但分布相对集中且沙漠化程度严重。(3)单因子探测结果显示,土壤质地对土地沙漠化敏感性空间分异的影响最显著,其次是土壤含水量;而交互作用结果显示,抗旱性、NPP、气温、土壤含水量和土壤质地等因子在特定组合下会极大增强其对土地沙漠化敏感性空间分异的影响。

The Horqin Sandy Land,as a vital component of the “Three-North” Shelter Forest Project,necessitates specific and urgent research on desertification within the region.This study innovatively introduces the Analytic Hierarchy Process(AHP) to select and optimize indicators and factor variables from the original MEDALUS model,thereby enhancing the model and developing a new evaluation system for land desertification sensitivity.This system integrates indicators from five aspects:climate,soil,vegetation,land management,and socio-economic factors to assess the sensitivity of land desertification.Furthermore,the study employs the Geographic Detector(GD) model to explore the factors influencing the spatial differentiation of land desertification sensitivity in the Horqin Sandy Land.The findings reveal that:(1) Vegetation quality index has the highest weight in the index system for assessing land desertification sensitivity,with a weight coefficient as high as 0.4624,followed by the climate and soil quality indices.(2) Areas sensitive to desertification in the Horqin Sandy Land account for 78.22% of the study area,indicating a broad distribution of affected regions.Although the proportion of highly sensitive and extremely sensitive areas is relatively small(8.77%),these areas are concentrated and severely desertified.(3) Single-factor analysis shows that soil texture has the most significant impact on the spatial differentiation of land desertification sensitivity,followed by soil moisture content.Interaction effects demonstrate that factors such as drought resistance,Net Primary Productivity(NPP),temperature,soil moisture content,and soil texture significantly enhance their impact on the spatial differentiation of land desertification sensitivity when combined.The findings of this study can provide a scientific basis for formulating targeted and reliable priority desertification prevention plans and sustainable development models for the region.