荒漠化及其系统过程

DESERTIFICATION AND ITS SYSTEMATIC PROCESS

荒漠化是全球重大的社会经济和环境问题。本文通过分析荒漠化及其系统过程认为，荒漠化是在土地利用系统中由于不合理的土地利用方式造成植被覆盖度下降，并通过一系列反馈机制形成的土地退化过程。由于系统内植被破坏对土壤侵蚀存在放大效应，应注重对我国南方山地丘陵水蚀荒漠化的研究。

Desertificetion is a global social economic and environmental problem. it has some features :1) It has loss in the function of landuse system.2) It occucs in the belt where environment is fragile.3) It has gradation.BY analysizing its systematic progress, some thoughts are raised in the paper: 1 ) Resulted from irreasonable landuse style in landuse system, desertification is a process of land degradation formed by a serious feedback mechanism trigged by decrease in vegetal cover, which has a megnifying effect on soil erosion.2) The study on desertification by water erosion in southeast hilly region of our country should be strengthened, which will do good both to theoretic study and to social practice.3) With the increase in water erosion, desertification goes through four stages, namely decrease in vegetal cover, and soil fertilith, clayed in texure, sandy in texure and stony in texture of soil respectively, whch can be used as indices of assessment of desertification by water.