北江红壤河岸坡面侵蚀水动力特征

发布时间：2018-07-07 23:53

本文选题：红壤 + 河岸坡面　；参考：《中国水土保持科学》2017年05期

【摘要】：受自然和人为干扰的交互影响,北江河岸带水土保持功能退化严重。本研究基于野外原位模拟径流冲刷试验,分析不同坡度(7°、9°、11°和15°)和放水强度(15、12和9 L/min)条件下红壤河岸坡面侵蚀水动力学参数变化特征及其与侵蚀产沙的关系。结果表明:1)平均流速随放水量增加而增加,在相同放水量下与坡度呈极显著线性正相关关系(P0.01);雷诺数随着放水时间增加总体上呈增大趋势,但增幅较小,坡度对雷诺数的影响较复杂,无明显规律;弗劳德数随放水历时增加呈先减小后趋于稳定,各处理的平均弗劳德数均1,说明坡面流均处于急流状态,且与坡度呈线性极显著正相关关系(P0.01);阻力系数随着放水时间增加总体呈增大趋势,且随坡度增加呈先增大后减小的趋势,说明阻力系数与坡度可能存在非线性关系。2)径流系数随放水历时增加呈先增大后趋于平稳趋势,相同放水量下随坡度增大而增大,同时坡度之间存在显著的幂函数关系(P0.05);侵蚀产沙量随着放水历时的增加呈先减小后稳定的趋势,且随坡度的增大而增大,二者之间存在显著的线性关系(P0.05)。3)侵蚀产沙量随水流剪切力和水流功率的增大而增大,且与二者之间均存在线性显著正相关关系(P0.01)。鉴于河岸带作为阻滞坡地泥沙进入河流的最后一道屏障,本研究的结果可为红壤河岸带坡面水土保持提供科学依据。
[Abstract]:Affected by the interaction of nature and human, the soil and water conservation function of Beijiang riparian zone is degraded seriously. Based on in situ simulated runoff scour experiments in the field, the characteristics of hydrodynamic parameters of erosion and sediment yield of red soil riverside slope under different slope (7 掳~ 9 掳~ (11 掳) and 15 掳) and water discharge intensity (15 ~ (12) and 9 L / min) were analyzed. The results showed that the average velocity of flow increased with the increase of water discharge, and showed a very significant linear positive correlation with the slope at the same discharge rate (P0.01), and the Reynolds number showed an increasing trend with the increase of the discharge time, but the increase was relatively small. The influence of slope on Reynolds number is more complex and has no obvious regularity, Froude number decreases first and then tends to be stable with the increase of discharge duration, the average Froude number of each treatment is 1, which indicates that the flow on the slope is in the state of jet flow. The coefficient of resistance increased with the increase of water release time, and increased first and then decreased with the increase of slope. 2) the runoff coefficient increases first and then tends to steady with the increase of discharge duration, and increases with the increase of slope at the same discharge rate. At the same time, there was a significant power function relationship between the slope (P0.05), the erosion sediment yield decreased first and then stabilized with the increase of discharge duration, and increased with the increase of slope. There was a significant linear relationship between them (P0.05). The amount of erosion sediment yield increased with the increase of water flow shear stress and flow power, and there was a significant linear positive correlation between them (P0.01). In view of the fact that riparian zone acts as the last barrier to prevent sediment from entering the river, the results of this study can provide scientific basis for soil and water conservation on the slope of red soil riparian zone.
【作者单位】：黄河中下游数字地理技术教育部重点实验室河南大学环境与规划学院;
【基金】：国家自然科学基金“华南红壤区河岸植被缓冲带景观格局对土壤侵蚀过程的调控机理研究”(41301197) 河南省高等学校重点科研项目“耦合植被格局与泥沙传输过程的河岸缓冲带水土保持功能调控技术”(18A170004) 河南省高校科技创新团队支持计划“农业资源开发与可持续利用”(16IRTSTHN012)
【分类号】：S157.1

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