黄土区退耕坡面植被恢复对坡沟系统侵蚀产沙的阻控研究

Slope-gully system is the key point connecting slope with river basin. The research on the response of slope-gully erosion relationship on vegetation restoration is of great importance to evaluate the water and soil reducing impact and formulate the controlling measures. Aiming at the situation of soil loss and the sudden reduction of sediment from the Yellow River, the project will be executed in the slope-gully system to study the vegetation recovery pattern under the context of large scale slope land abandoned in the Loess Plateau. Based on the simulation,observation and REE tracing method, the characteristics of sediment yield with different vegetation pattern will be studied, the difference of blocking and controlling consequences on sediment-heavily containing flows between vegetation on Mao slope and gully slope be analyzed, the mechanism of vegetation restoration and its pattern on sediment yield from slope-gully system to be illuminated. The contribution of vegetation restoration of different period on sediment and runoff controlling should be clarified systematically. This study will provide reference basis for the establishment of parameters coupling pattern information with the course of soil loss and the study has important theoretical and practical significance for the construction of ecological environment.

坡沟系统是联系坡面和流域的关键，研究坡沟侵蚀产沙对植被恢复的过程响应机制，对于评价黄土高原植被措施的减水减沙作用和制定科学的水土流失调控措施具有重要意义。本项目针对黄土高原水土流失及其治理特点与近期黄河水沙的变化特征，以最基本的坡沟系统为对象，研究黄土高原当前大规模坡面退耕条件下的植被恢复格局特征，采用室内模拟与田间原位观测相结合的方法，通过稀土元素示踪，分析不同坡面植被恢复格局下坡沟系统侵蚀产沙特征，明确峁坡草被和沟坡草被覆盖格局对高含沙水流的阻控效应差异，阐明坡面植被覆盖及其格局对坡沟侵蚀产沙的调控作用机理，系统分析退耕坡面不同植被恢复阶段的侵蚀调控贡献，为建立耦合格局与产流产沙过程的植被覆盖参数和旱区植被的优化布局提供科学依据。

坡沟系统是联系坡面和流域的关键，研究坡沟侵蚀产沙对植被恢复的过程响应机制，对于评价黄土高原植被措施的减水减沙作用和制定科学的水土流失调控措施具有重要意义。本项目针对黄土高原水土流失及其治理特点与近期黄河水沙的变化特征，以最基本的坡沟系统为对象，采用室内模拟与田间原位试验相结合的方法，分析不同坡面植被恢复格局下坡沟系统侵蚀产沙特征。在坡沟系统中，坡面植被覆盖度与侵蚀产沙量无显著相关关系，各水力学参数中，径流剪切力和水流功率与侵蚀产沙量相关关系显著；说明，仅在峁坡布设草被对坡沟系统侵蚀产沙阻控效应不明显；在退耕不同阶段，土壤团聚体含量、有机质含量增多，土壤可蚀性减弱，抗侵蚀力增强，植被格局参数PLAND、SPLIT等参数可以系统反应不同退耕时期植被与侵蚀产沙关系的关系。本研究可为建立耦合格局与产流产沙过程的植被覆盖参数和旱区植被的优化布局提供科学依据。