关键词: 沙漠化程度, 沙漠化过程, 数量表征, k值曲线

Abstract: In this paper we emphasized that desertification could be described in two items;these were desertification degree and desertification process.Among of these,the desertification degree has been defined as relative area of total weighted influence of different dune types in research region and expressed as DG_i=(M_i+k₁SM_i+k₂F_i)/A_i(where DG_i is the desertification degree;M_i,mobile dune area;SM_i,semi-fixed dune area;F_i,fixed dune area;k₁,k₂;weights.).Simultaneously,the desertification process defined the change ratio of the desertification degree in certain period and calculated by DP=(DG_i+n-DG_i)/n(where DP means the desertification process;DG_i+n and DG_i,the different temporal desertification degree.).How to make sure k value value significantly influenced the desertification degree.Results showed that the values were positively correlative with the desertification degree.Distinctively,the effects of changing scope which induced by the values was less than the change of areas of different dune types,because major aspect of the functions emphasized the information of different dune types areas in region scale.However,the values just modified the different dune types areas.Meantime,results also showed that relation between the values and the desertification was linear regression,the deviation of the desertification degree and process that induced by the values could be recalculated and modulated by using the k values curve.In addition,the values curve as well as expressed the changing scope of the desertification degree and process in study region under the different dune type areas were unchangeable.

Key words: desertification degree, desertification process, quantitative expression, k values curve