不同流量级组合下细沟侵蚀产沙机理研究  

Study on the Mechanism of Rill Erosion and Sediment Yield with Different Flow Types

作　　者：许强强 张宽地[1,2] 任涓 XU Qiang-qiang;ZHANG Kuan-di;RENG Juan(State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau,Northwest A&F University,Yangling 712100,Shaanxi Province,China;College of Water Resources and Architectural Engineering,Northwest A&F University,Yangling 712100,Shaanxi Province,China)

机构地区：[1]西北农林科技大学黄土高原土壤侵蚀与旱地农业国家重点实验室,陕西杨凌712100 [2]西北农林科技大学水利与建筑工程学院,陕西杨凌712100

出　　处：《节水灌溉》2022年第7期71-78,共8页Water Saving Irrigation

基　　金：国家自然科学基金项目(52179079)。

摘　　要：不同降雨径流条件下,黄土高原地区坡耕地会产生土壤侵蚀,影响坡耕地品质和农业灌水均匀度。为探明不同流量类型条件下该地区细沟侵蚀产沙机理,采用室内放水冲刷试验,对4种流量类型(凹陷型(5.0-2.5-7.5 L/min)、峰值型(2.5-7.5-5.0 L/min)、均匀型(5.0-5.0-5.0 L/min)、增加型(2.5-5.0-7.5 L/min))与3个坡度(4°、8°、12°)组合工况下的细沟侵蚀产沙过程进行研究。结果表明:同一坡度下,土壤剥蚀率最大的流量类型为峰值型,均匀型流量类型冲刷下的剥蚀率次之(除坡度4°外);峰值型、凹陷型和增加型的土壤剥蚀率分别为均匀型的1.36倍、0.91倍和0.95倍;土壤剥蚀率与坡度显著相关(P<0.05),且随坡度的增大而增大;土壤剥蚀率与水流强度参数(剪切力、水流功率、有效水流功率)之间的关系均能很好地用幂函数描述(R^(2)=0.37~0.94);土壤剥蚀率与消能率呈正相关(幂函数关系),且峰值型的土壤剥蚀率与消能率间的相关性最强,其次是增加型和均匀型,凹陷型最弱;细沟水流挟沙系数变化范围为20.84~83.57,平均值为52.21,相对应的不淤保证率为95%。各研究结果对阐明不同流量级组合冲刷下黄土高原地区黄绵土土质坡面侵蚀产沙机理具有重要意义,可望为该地区侵蚀预报模型的建立和防治侵蚀提供理论支持。Under different rainfall and runoff conditions,soil erosion will occur in sloping farmland in the Loess Plateau,which affects the quality of sloping farmland and the uniformity of agricultural irrigation.This study aimed to explore the mechanism of rill erosion and sediment yield under different flow discharge patterns on the loess slope through using three slopes(4°,8°,12°)and four flow discharge types,including recessed type(5.0-2.5-7.5 L/min),peak type(2.5-7.5-5.0 L/min),uniform type(5.0-5.0-5.0 L/min)and increased type(2.5-5.0-7.5 L/min).These conditions were combined in an indoor water-scouring test to study the rill erosion and sediment yield process.The results showed that under the same slope,the flow discharge type with the largest soil erosion rate was the peak type,followed by the uniform type(except for the slope of 4°).The soil erosion rates of peak type,recessed type and increased type were 1.36 times,0.91 times and 0.95 times of that of uniform type,respectively.The erosion rate was positively correlated with the slope(P<0.05);the erosion rate under the same flow type increased with the increase of the slope.The relationship between the erosion rate and the flow intensity parameters(shear stress,stream power,effective stream power)could be described by a power function(R^(2)=0.37~0.94).The erosion rate was positively correlated with the energy dissipation rate(power function relationship),and soil erosion rate of the peak type changed most significantly with the energy dissipation rate,followed by the increased type,the uniform type and the recessed type.The variation range of sediment carrying coefficient was 20.84 to 83.57,with an average of 52.21,and the corresponding non-deposition guarantee rate was 95%.The results of this study are of great significance to clarify the mechanism of soil erosion and sediment yield on loess soil slopes in the Loess Plateau under different flow types scouring,and will provide theoretical support for the establishment of erosion prediction models and erosion c

关 键 词：细沟侵蚀 流量类型 土壤剥蚀率 水流强度参数 消能率 

分 类 号：S27[农业科学—农业水土工程] S157.1[农业科学—农业工程]