黄土高原小流域植被恢复和坡改梯工程耦合的生态水文机理

植被和工程措施是干旱山地生态修复和水蚀防治的两大核心手段。鉴于流域植被恢复和坡改梯工程及其时空格局的复杂多样性，其综合作用下的生态水文机理亟待更深入研究。本项目以黄土高原典型小流域为核心案例区，基于子流域对比、多点定位观测、高清遥感影像解译、无人机航测等手段，结合长期系统积累、历史资料集成和全流域详查，揭示流域不同历史时期各类坡改梯工程和人工植被的具体类型、面积比例和分布格局及其演变规律，探讨长期人工综合治理措施对流域植被覆盖和微地貌格局的影响程度与作用机制；从多个时间尺度（次降雨、日、旬、月、年、多年、年代）和空间尺度（典型坡面、重点子流域和全流域），阐明不同植被恢复模式和坡面工程措施及其镶嵌格局对蓝绿水转化（径流产水、土壤水分、蒸散发等）、水量平衡、侵蚀产沙及其与地表水文的关联过程的影响机制。研究结果可为优化流域下垫面植被配置和坡改梯综合布局、遏制土地退化和促进生态恢复提供科学依据。

Vegetation and terracing are key measures for ecological restoration and water erosion control in the dryland mountainous regions. Due to the diversity and complexity of vegetation type and terracing measures as well as their spatiotemporal patterns, their coupling effects on eco-hydrological mechanisms need urgent and further study. In this project, a small typical watershed in Dingxi of Gansu province was selected as the key study region. Based on sub-catchment comparison analysis, multiple-sites of hydrological measurements, high-resolution image interpretation, UAV aerial photography, long-term accumulation and historical data synthesis, the specific types, covered area ratio and changing patterns of terracing and vegetation communities across different historical periods will be detected. We want to analyze how long-term ecological-restoration measures can affect watershed topography and vegetation patterns. From various spatiotemporal scales, the different responses of vegetation-terracing patterns on the green and blue water flows (such as runoff, water yield, soil moisture and evapotranspiration), water balance, erosion and sediment transportation and their connections with hydrological processes will be analyzed. We hope this study can provide key scientific references for watershed arrangement of vegetation and terracing, fighting against land degradation and enhancing the process of vegetation restoration at watershed scales.