什么样的退化土地才是荒漠化土地，土地荒漠化的发生发展以及程度和区别等问题的定量确定，至今有关报道甚少。干热河谷是我国西南地区特殊的生态环境类型，自然资源丰富，但土地荒漠化问题十分突出，这一现象的定量认识尤为重要。针对土地景观生态系统的复杂和模糊性，在建立评价指标的基础上，采用模糊综合评判的方法，对土地荒漠化程度进行定量评价，为荒漠化土地的预防和防治提供科学依据和决策支持。

Arid-hot valleys are special ecological type in southwest China. Land degradation/desertification is very severe in the arid-hot valley of the Jinshajiang River, the upstream of the Yangtze River, and threatens residents living and sustainable development of national economy. The study on land desertification presently include type, distribute, cause of formation, harm, process and principle of forming. Land desertification degrees are still determined qualitatively. In order to take some countermeasures, rapid and accurate evaluation to the land desertification in this region should be done. The degrees of land degradation/desertification are determined by element analysis and multiplayer fuzzy evaluation in accordance with the complexity and fuzziness of land ecological system. The study shows those as following: Physiognomy, soil and vegetation is important factors for evaluation to land desertification in the arid-hot valley of the Jinshajiang River. According to the evaluation criteria system land desertification degrees are determined quantitatively with fuzzy evaluation. The evaluation result is accurate and reliable. It can tell us not only the degree of land degradation/desertification, but also its developing tendency and provide scientific basis and support of policy decision for the prevention of Land degradation/desertification and bringing it under control.