作 者：
王文鑫;王文龙;康宏亮;郭明明;杨波;陈卓鑫;赵满
单 位：
西北农林科技大学水土保持研究所黄土高原土壤侵蚀与旱地农业国家重点实验室;西北农林科技大学水土保持研究所
关键词：
浅沟侵蚀;自然恢复草被;径流;产沙;侵蚀动力学;黄土丘陵沟壑区
摘 要：
浅沟侵蚀是黄土高原丘陵沟壑区的一种重要侵蚀类型.以往研究多侧重于农地浅沟,有关自然恢复草被对浅沟侵蚀影响的研究甚少.本研究采用野外原位冲刷试验,以裸地浅沟为对照,探究放水流量为5、10、15、20和25 L·min~(-1)条件下草地浅沟的径流产沙特征及侵蚀机理.结果表明:与裸地相比,草地浅沟平均流速、稳定径流率、雷诺数、弗劳德数分别减小25.4%～67.3%、8.4%～26.6%、54.9%～80.5%、18.6%～65.1%,阻力系数增大0.09～7.18倍.草地浅沟最大产沙率、稳定产沙率和平均产沙率较裸地浅沟分别减小55.1%～90.9%、61.8%～95.4%和64.8%～92.4%; 5～25 L·min~(-1)放水流量下,自然恢复草被的减沙效益可达65.9%～88.8%,且随放水流量增大,减沙效益呈减小趋势.与裸地相比,草地浅沟的平均径流功率和平均径流剪切力分别减小54.9%～80.5%和12.4%～51.1%,临界径流功率增大1.43倍,临界剪切力增大33.7%;草地和裸地浅沟平均产沙率与平均径流功率、平均径流剪切力均呈显著线性相关.自然恢复草被显著增加了浅沟抗蚀性能,降低了浅沟径流侵蚀能力.
译 名：
Effect of naturally restored grassland on the ephemeral gully erosion in the loess hilly and gully region
作 者：
WANG Wen-xin;WANG Wen-long;KANG Hong-liang;GUO Ming-ming;YANG Bo;CHEN Zhuo-xin;ZHAO Man;State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateaus,Institute of Soil and Water Conservation,Northwest A&F University;Key Laboratory of Ecological Restoration of Mining Area in Northern Shaanxi,Yulin University;Institute of Soil and Water Conservation,Chinese Academy of Sciences & Ministry of Water Resources;
单 位：
WANG Wen-xin%WANG Wen-long%KANG Hong-liang%GUO Ming-ming%YANG Bo%CHEN Zhuo-xin%ZHAO Man%State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateaus,Institute of Soil and Water Conservation,Northwest A&F University%Key Laboratory of Ecological Restoration of Mining Area in Northern Shaanxi,Yulin University%Institute of Soil and Water Conservation,Chinese Academy of Sciences & Ministry of Water Resources
关键词：
ephemeral gully erosion;;naturally restored grassland;;runoff;;sediment;;erosion dynamics;;loess hilly and gully region
摘 要：
Ephemeral gully erosion is an important erosion type in hilly and gully regions of Loess Plateau. While previous studies mainly focused on ephemeral gullies in agricultural land,little is known about the effects of naturally restored grassland on ephemeral gully erosion. In this study,taking the bare ephemeral gullies as the baseline,we conducted in-situ flushing tests to explore runoff and sediment yield characteristics and erosion mechanism of grassland ephemeral gullies under the runoff conditions of 5,10,15,20 and 25 L·min~(-1). Compared to the bare ephemeral gully,average flow velocity,stable runoff rate,Reynolds number and Froude number of grassland ephemeral gullies was reduced by 25. 4%-67. 3%,8. 4%-26. 6%,54. 9%-80. 5%,18. 6%-65. 1%,respectively,whereas resistance coefficient was increased by 0.09-7.18 folds. Compared to the bare ephemeral gully,the maximum sediment yield rate,stable sediment yield rate,average sediment yield rate of grassland ephemeral gullies was decreased by 55. 1%-90. 9%,61. 8%-95. 4%,and64.8%-92.4%,respectively. The sediment yield reduction benefit of the naturally restored grassland under the discharge flow rate of 5-25 L·min~(-1) could reach 65.9%-88.8%,which decreased with increasing discharge flow rate. Compared to the bare ephemeral gully,average stream power and average shear stress of grassland ephemeral gullies was reduced by 54.9%-80.5% and 12.4%-51.1%,respectively,whereas the critical stream power and critical shear stress was increased by1.43 folds and 33.7%,respectively. The average sediment yield of grassland and bare ephemeral gullies was signifi-cantly linearly related to average stream power and shear stress. Naturally restored grassland significantly increased the erosion resistance and reduced runoff erosion potential of ephemeral gullies.
