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

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.