毛乌素沙地沙漠化及其逆转过程与生态系统水分利用效率关系研究

生态系统水分利用效率（EWUE）是评价土地沙漠化发展、逆转及防沙治沙实施效果的重要因素。然而，目前沙漠化与EWUE的关系尚不清楚，EWUE是否能有效指示沙漠化尚待验证，严重制约了沙漠化过程的评估及其防治措施的实施，有必要开展不同沙漠化过程EWUE变化规律及阈值判定分析研究。本项目拟以毛乌素沙地为研究区，依据MODIS数据、CASA模型、PT-JPL模型及其他辅助数据，反演沙漠化监测与评估指标，优化指标组合与方法，确定研究区土地沙漠化现状、程度及演变过程；估算研究区2000-2023年植被生产力（NPP）和蒸散发（ET），分析EWUE的时空变化格局与影响因素；结合野外实测与关联规则，从遥感大数据样本中获取不同沙漠化过程与EWUE变化的关系，判定划分不同沙漠化阶段及过程的EWUE阈值，并评价EWUE指示沙漠化信息的能力；为依据碳-水耦合关系评估大尺度的沙漠化提供理论基础和科技支撑。

As one of key factors during the assessment and prevention of Aeolian desertification, Ecosystem Water Use Efficiency (EWUE), indicating coupled carbon-water process, should be paid much more attention. However, the variation and thresholds of EWUE among different Aeolian desertification processes, and the indication of EWUE to Aeolian desertification remain unclear. In this program, with field investigation data, MODIS products, CASA model, PT-JPL model and other auxiliary data, the indicators, firstly, will be inversed to monitor and evaluate the status, degrees and dynamics of Aeolian desertification in the Mu Us sandy land. Then, the NPP and ET will be estimated from 2000 to 2013 to analyze the spatial-temporal trends of EWUE, meanwhile the influence factors of EWUE will be discussed with correlation analysis. Based on that, the relationship between Aeolian desertification and EWUE will be explored by Association Rules Mining (ARM), and the variation and thresholds of EWUE during Aeolian desertification will be determined to analyze whether EWUE could indicate Aeolian desertification effectively. After that, it will be helpful to provide the theory and technical support for assessing Aeolian desertification process at large scale, and to provide the references for the ecological restoration and management of sandy lands.