干旱地是指以水资源短缺为主要特征的地区。我国干旱地主要分布于西北部，约占国土总面积的44%。近年来，我国干旱地城市化进程不断加快，社会经济高速发展，导致生态环境持续恶化，生态系统服务（Ecosystem Service，ES）供需矛盾日益突出。因此亟需理解快速城市化干旱地ES供给与需求的时空格局和内在联系，为揭示ES与人类福祉的关系，进而提高区域可持续性提供科学依据。但已有研究主要集中于分析ES潜在供给，ES实际供给和需求研究较少。为此，本项目拟以正在经历快速城市化的呼包鄂榆地区为研究区，系统开展生态系统服务供需动态研究。首先结合实地调查、遥感测量和模型模拟，量化区域1990-2015年ES实际供给和需求的时空格局；然后在多个尺度上分析ES供需时空关联，探寻ES供需关系优化途径，以在最大程度上实现区域ES供需平衡。成果可以为完善ES供需分析方法提供帮助，也可以为实现区域可持续发展提供支持。

Drylands are areas characterized by lack of water. In China, drylands are mainly distributed in the Northwest, and approximately account for 44% of the land area. Recently, the rapid urbanization and socioeconomic development have been resulting in environmental degradation, which is aggravating the imbalance between supplies and demands of ecosystem services (ES) in China's drylands. Thus, it is urgent to understand the spatiotemporal patterns of ES in terms of supplies and demands and their interactions in rapidly urbanizing drylands, for finding out the relationships between ES and human well-being and promoting regional sustainability. However, most of the existing studies focused on potential supplies of ES, whereas few were devoted to the actual supplies and demands of ES. In this project, our objective is to understand the patterns of supplies and demands of ES and their relationships in space and time over the Hohhot-Baotou -Ordos-Yulin (HBOY) region under fast urbanization. We plan to integrate field surveys, remote sensing techniques, and ecological models to quantify the spatiotemporal patterns of ES in terms of supplies and demands from 1990 to 2015 in HBOY region, analyze the relationships between them at multiple scales, and optimize the relationships for maximally matching local ES supplies with demands. The results are helpful in improving the methods relevant to analysis of ES supplies and demands, and achieving the regional sustainable development.