黄土高原典型流域次降雨径流侵蚀产沙规律研究

Research on runoff erosion and sediment yield laws of typical watershed under single rainfall on Loess Plateau

【目的】研究黄土高原地区小流域次降雨径流侵蚀产沙规律,建立适宜于该地区的侵蚀产沙预报模型。【方法】根据岔巴沟流域32年实测的水沙资料,采用径流侵蚀功率、地貌分形信息维数的计算模型及多元非线性回归方法,分析了黄土高原地区岔巴沟流域的次降雨径流侵蚀产沙规律。【结果】岔巴沟流域次降雨侵蚀产沙模数Ms与径流侵蚀功率E、地貌形态分形信息维数Di有很好的相关性,模型具有较高的精度和一定的适用性。【结论】基于流域径流侵蚀功率与地貌形态分形信息维数的岔巴沟流域次降雨侵蚀产沙预报模型,能够近似反映不同尺度流域次降雨径流侵蚀产沙特性及水沙传递的关系,为建立具有广泛适用性和较高预报精度的黄土高原流域次降雨径流侵蚀产沙预报模型提供了理论依据。

[Objective] To study the laws of soil erosion and sediment yield under single rainfall runoff in small watershed on Loess Plateau, the soil erosion and sediment yield prediction model adapted to this region was established. [Method] Adopted runoff erosion power model and topographical fractal information dimension model on basis of observed data of runoff and sediment in Chabagou watershed for 32 years, the sediment yield laws under single rainfall runoff was analyzed through applying multielement nonlinear regression method. [Result] The result showed that there was close relation between sediment yield modulus M, and runoff erosion power E, topographical fractal information dimension Di, the model had good precision and definite applicability. [Conclusion] Based on runoff erosion power, geomorphological features and topographical fractal information dimension,the forecast model for runoff erosion in Chabagou watershed under single rainfall can roughly reflect the characteristics and its relationship with water and sediment power. This research will provide theoretical basis to establish watershed runoff erosion and sediment yield predictive model which had comprehensive applicability and preferable prediction precision on Loess Plateau.