金沙江干热河谷土地荒漠化评价指标体系研究

Study of Index System for Land Desertification Assessment in the Dry-hot Valley Area of Jinsha River

土地荒漠化的评价是土地荒漠化研究中的重要理论问题，根据多年对金沙江干热河谷土地荒漠化形成机制、影响因子及荒漠化土地的表现特征等的研究，提出了土地荒漠化评价的原则，并通过对各影响因子在土地荒漠中贡献率的分析和筛选，选择出能显著评价土地荒漠化程度的三个因子，五个指标，即地貌因子的切割密度和坡度，土壤因子的土壤厚度和有机质含量，植被因子的植被指数。在大量样方测算和样品分析的基础上给出每个指标的量化标准，首次建立了金沙江干热河谷土地荒漠化的评价指标体系。针对土地景观生态系统的复杂性和模糊性，在建立评价指标体系的基础上，采用模糊综合评判的方法，对土地荒漠化程度进行定量评价，为荒漠化土地的预防和治理提供科学依据和决策支持。

Land desertification assessment is an issue of important theory of land desertification study. The assessment principle is proposed through the study on characteristic, formation mechanism and influencing factors of the land desertification in the dry-hot valley area of Jinsha River. Based on analysis of factors' loading to land desertification, three main influencing factors (including five assessment indexes): geomorphology (cutting density, slope), soil (soil thickness, soil organic matter content) and vegetation (vegetation index) are selected. Quantitative classification of each assessment index is proposed through investigation into many sample plots and analyses and calculation. The assessment index system of land desertification in the dry-hot valley area of Jinsha River is firstly raised. The degrees of land degradation/desertification are determined by element analysis and multiplayer fuzzy evaluation in accordance with the complexity and fuzziness of land ecological system. The evaluation result can not only tell us the degree of land degradation/desertification, but also tell us its developing tendency and provide scientific basis and support of policy decision for the prevention and control of land degradation/desertification.