区域沙漠化程度评价研究进展、问题及分析

Research Progresses, Problems and Analyses of the Evaluation on Regional Sandy Desertification

通过回顾景观尺度及区域尺度的沙漠化程度评价发展过程,概括了国内外典型的区域沙漠化程度评价方法,通过假设各种情景分析、总结了目前各类区域沙漠化程度评价方法中存在的典型共性问题:(1)当被比较评价的几个区域中各类沙化土地面积相等时,目前所有的评价模型失去比较能力;(2)忽略了不同类型沙化土地空间分布的生态学意义及其对区域沙化整体程度的影响;(3)目前考虑了不同类型沙化土地空间分布的模型由于指标因子选择不恰当其评价结果在有些情况下与实际情况有距离。提出了在现有评价方法的基础上根据景观生态学原理引进景观生态学方法,特别是景观格局分析的方法,可以弥补现有区域沙漠化程度评价方法中存在的缺陷和不足,并且可以使区域沙漠化程度评价具有生态学意义。

In this paper, the research progresses of the evaluation about sandy desertification degree on landscape and regional scales are reviewed, and several typical domestic and overseas methods of evaluating regional sandy desertification are summed up. By means of scenario hypothesis the typical common problems in all kinds of methods of evaluating regional sandy desertification degree are analyzed. The existing problems are as follows: (1) When the areas of all the evaluated sandy desertified land types in several regions are equal to, all the current evaluation models fail to compare their regional sandy desertification; (2) The ecological significance and impacts of spatial distribution of different desertified land types on regional desertification degree are ignored in all the current evaluation models; (3) The evaluation results of the models in which the impacts of spatial distribution of different desertified land types are considered do not accord with the practical instances, because the selected indexes for explaining the ecological significance of spatial distribution of the different desertified land types are not appropriate. In order to overcome the problems in evaluating the regional sandy desertification degree, it is suggested to introduce the methods of landscape ecology, especially landscape pattern analysis methods, into the evaluation of regional sandy desertification degree based on the landscape ecology principles and the present evaluation methods, thus, the problems in present evaluation methods of regional sandy desertification degree may be avoided, and the regional sandy desertification evaluation will gradually possess ecological significance.