Effects of grass density on the runoff hydraulic characteristics and sediment yield in gully headcut erosion processes
Effects of grass density on the runoff hydraulic characteristics and sediment yield in gully headcut erosion processes
复制标题
草密度对沟壑冲刷过程径流水力特征及产沙量的影响
DOI：
10.1002/hyp.14643
复制
发表时间：
2022-07
影响因子：
3.2
通讯作者：
Zhuoxin Chen
中科院分区：
文献类型：
--
作者：
Lanqian Feng;Wenlong Wang;Mingming Guo;Qianhua Shi;Wenzhao Guo （郭文召）;Yibao Lou;Hongliang Kang;Zhuoxin Chen
植被在沟头溯源侵蚀中起着至关重要的作用。然而，关于草如何影响径流水力学、土壤侵蚀和沟头溯源侵蚀过程，人们知之甚少。在四块样地进行了一系列降雨和冲刷实验，以阐明冰草（Agropyron cristatum (L.) Gaertn）密度（种植间距：20×20平方厘米，GA1；15×15平方厘米，GA2；10×10平方厘米，GA3；裸地作为对照，BL）对沟头溯源侵蚀过程中径流水力学和土壤侵蚀的影响。裸地的流速、雷诺数（Re）、径流切应力（τ）和水流功率（ω）随时间呈指数增长（P < 0.01）。然而，对于草地而言，大多数参数随时间呈线性增长（P < 0.01）。裸地和草地的弗劳德数（Fr）分别随时间呈显著的线性和指数下降（P < 0.01）。对于τ，草地需要一段时间的发育才能对其起到抑制作用。裸地和沟头的径流为超临界紊流，而草地的径流则更为分散。沟头的存在使射流速度提高了2.97% - 67.19%，这增加了径流的分散程度。径流能量随时间呈显著的指数增长（P < 0.05）。与裸地相比，草地径流的能量消耗增加了4.10% - 31.81%。在沟头溯源侵蚀过程中，裸地主要被径流切割至台地，而草地则被壁面流切割至沟头壁。随着密度的增加，减沙效益增加，最高可达66.79%。在实验早期，裸地的坍塌主要发生在沟头壁的上部。草地坍塌的频率和时空范围比裸地更大。裸地的重力侵蚀类型为沟头壁坍塌和沟岸坍塌，而草地的重力侵蚀类型为沟头壁坍塌和根 - 土复合坍塌。
Vegetation plays a crucial role in gully headcut erosion. However, little is known about how grass influences runoff hydraulics, soil erosion and headcut erosion processes. A series of rainfall and scouring experiments were conducted on four plots to elucidate the effect of the density of Agropyron cristatum (L.) Gaertn (planting spaces: 20 × 20 cm2, GA1; 15 × 15 cm2, GA2; 10 × 10 cm2, GA3; bare land as control, BL) on runoff hydraulics and soil erosion during gully headcut erosion. The velocity, Reynolds number (Re), runoff shear force (τ) and stream power (ω) of the BL increased exponentially with time (P < 0.01). However, for the grassland, most parameters increased linearly with time (P < 0.01). The Froude number (Fr) of the BL and grassland significantly decreased linearly and exponentially, respectively, with time (P < 0.01). For τ, the grass tableland needed to develop for a period of time to restrain it. The runoff of the BL tableland and gully head was supercritical turbulent, while that of the grassland was more dispersed. The existence of a gully head increased the jet velocity by 2.97%–67.19%, which increased the dispersion degree of the runoff. The runoff energy showed a significant exponential increase with time (P < 0.05). Compared with that of the BL, the energy consumption of the runoff from the grassland increased by 4.10%–31.81%. During gully headcut erosion, the BL was primarily cut down to the tableland by runoff, while the grassland was cut down to the headwall by on-wall flow. As the density increased, the benefit of sediment reduction increased, reaching a maximum of 66.79%. The collapse of the BL primarily occurred in the upper part of the headwall during the early experimental stage. The frequency and space–time ranges of the collapse of the grassland were larger than those of the BL. The gravity erosion types of the BL were headwall collapse and gully bank collapse, while those of the grasslands were headwall collapse and root-soil composite collapse.
登录
查看更多内容
影响因子：
6.2
作者：
Avni, Y
通讯作者：
Avni, Y
影响因子：
3.9
作者：
N. Pollen-Bankhead;A. Simon
通讯作者：
N. Pollen-Bankhead;A. Simon
初始台阶高度对岸沟切头侵蚀的影响——以西南干热河谷地区3D照片重建法为例
影响因子：
1.6
作者：
Zhang Baojun;Xiong Donghong;Su Zhengan;Yang Dan;Dong Yifan;Xiao Liang;Zhang Su;Shi Liangtao
通讯作者：
Shi Liangtao
影响因子：
8.7
作者：
D. Rockwell
通讯作者：
D. Rockwell
影响因子：
3.8
作者：
A. Khanal;G. Fox
通讯作者：
A. Khanal;G. Fox