新疆沙漠化防治区划指标和方法

Indexes and Methods of Regionalization for Sandy Desertification Prevention and Control in Xinjiang

考虑到资料可获取性和指标的适用性以及新疆沙漠化的具体特点,新疆沙漠化防治区划工作在第三级区划中设计和采用了沙尘天气指数、土地覆被指数、植被盖度指数、大风指数和海拔高程指数作为区划主体指标,同时还采用了自然地理单元、县级行政区划界线、雨养植被界线、耕居地人口密度、人口耕居地比例作为辅助指标。最后,把由主体指标经指数和法合成的沙漠化综合评级指数作为最主要依据,划定三级区划界线。

Regionalization for sandy desertification prevention and control is of great importance in arid and semiarid regions. Up to now, however, the researches on regionalization for sandy desertification prevention and control in Xinjiang are neither systematic and nor comprehensive. Considering this, a regionalization scheme for sandy desertification prevention and control in Xinjiang is carried out by us recently. In this paper, the indexes and methods of this scheme are mainly introduced. In order to link up with the national regionalization for sandy desertification prevention and control, the names of two subareas in Xinjiang in the ＂national anti-desertification planning＂ are changed only, and these two subareas are taken as the first-level subareas. The genetic and evolutional conditions of sandy desertification in Xinjiang are. quite different because Xinjiang is vast, and the second-level subareas are delimited based on the large morphologic units. Five main indexes, i.e. the sand weather index, land cover index, vegetation coverage index, gale index and elevation index, are used in the third-level regionalization on the basis of the second-level subareas and in view of the available data, the applicability of indexes used by former scholars and the characteristics of sandy desertification in Xinjiang. Moreover, other 4 factors, i.e. the physiogeographic units, county-level administrative boundaries, rain-fed vegetation boundaries, population density of farmlands and residential areas, and population-farmland proportion, are used as the subsidiary indexes, and then the third-level subareas and their boundaries are delimited.