模拟砾石对不同流量、坡度和砾石覆盖度下坡面漫流水力特性的影响。

Effects of Simulated Gravel on Hydraulic Characteristics of Overland Flow Under Varying Flow Discharges, Slope Gradients and Gravel Coverage Degrees.

机构信息

Beijing Forestry University, Key Laboratory of Soil and Water Conservation and Desertification Combating, State Forestry Administration, Beijing, 100083, China.

Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, 210037, China.

出版信息

Sci Rep. 2019 Dec 24;9(1):19781. doi: 10.1038/s41598-019-56223-2.

DOI:10.1038/s41598-019-56223-2

PMID:31874992

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC6930202/

Abstract

To quantify the hydraulic characteristics of overland flow on gravel-covered slopes, eight flow discharges (Q) (8.44-122 L/min), five slope gradients (J) (2°-10°) and four gravel coverage degrees (Cr) (0-30%) were examined via a laboratory flume. The results showed that (1) gravel changed flow regime. Gravel increased the Reynolds number (Re) by 2.94-33.03%. Re were less affected by J and positively correlated with Cr and Q. Gravel decreased the Froude number (Fr) by 6.83-77.31%. Fr was positively correlated with Q and J and negatively correlated with Cr. (2) Gravel delayed the flow velocity (u) and increased the flow depth (h) and flow resistance (f). Gravel reduced u by 1.20-58.95%. u was positively correlated with Q and J and negatively correlated with Cr. Gravel increased h by 0.12-2.41 times. h was positively correlated with Q and Cr and negatively correlated with J. Gravel increased f by 0.15-18.42 times. f were less affected by J, positively correlated with Cr and negatively correlated with Q. (3) The relationships between hydraulic parameters and Q, J and Cr identified good power functions. Hydraulic parameters were mainly affected by Cr. These results can guide the ecological construction of soil and water conservation.

摘要

为了量化覆砾坡面漫流的水力特性，通过实验室水槽试验，研究了 8 种流量（Q）（8.44-122L/min）、5 种坡度（J）（2°-10°）和 4 种砾石覆盖度（Cr）（0-30%）对水力特性的影响。结果表明：（1）砾石改变了水流流态。砾石使雷诺数（Re）增加了 2.94-33.03%。Re 受 J 的影响较小，与 Cr 和 Q 呈正相关。砾石使弗劳德数（Fr）降低了 6.83-77.31%。Fr 与 Q 和 J 呈正相关，与 Cr 呈负相关。（2）砾石延迟了流速（u），增加了水深（h）和水流阻力（f）。砾石使 u 降低了 1.20-58.95%。u 与 Q 和 J 呈正相关，与 Cr 呈负相关。砾石使 h 增加了 0.12-2.41 倍。h 与 Q 和 Cr 呈正相关，与 J 呈负相关。砾石使 f 增加了 0.15-18.42 倍。f 受 J 的影响较小，与 Cr 呈正相关，与 Q 呈负相关。（3）水力参数与 Q、J 和 Cr 的关系可以用较好的幂函数来表示。水力参数主要受 Cr 的影响。这些结果可以为水土保持的生态建设提供指导。