Abstract:

Land desertification is a very important ecological and environmental problem， and the necessary prerequisite for desertification control and zero-growth goals is to have a complete and unified evaluation system. Therefore， the United Nations Convention to Combat Desertification （UNCCD） proposed the concept and monitoring indicators of Land Degradation Neutrality （LDN）. The prevention and control of soil degradation is also one of the important ecological goals to be achieved in China. China has carried out several national desertification and sandification survey. However， how to use the survey results in the assessment practice of land degradation has not been reported yet. Therefore， aiming at the typical areas of four major sandy land in China， this study makes a comparative analysis of LDN indicators based on the framework system of UNCCD by using three phases of national desertification and sandification survey data， and proposes a desertification land degradation indicator system CLSDN that is more suitable for this region based on the change trend of land desertification degree. The results show that the overall accuracy of the LDN monitoring indicators proposed by UNCCD and the desertification monitoring data in China is 0.51， and China's desertification land monitoring indicators and LDN indicators have macro consistency. In addition， the locally optimized CSLDN index overcomes the problem of inaccurate evaluation of land degradation and restoration by LDN in low vegetation coverage areas， and more accurately depicts the dynamic changes of land in fine-scale space， which is of great significance to the prevention and control of land degradation.

Key words: land degradation, SDG15.3, monitoring indicators, LDN, desertification and sandification land monitoring