Comparing erosion and rill development processes by simulated upslope inflow in two red soils from subtropical China
Comparing erosion and rill development processes by simulated upslope inflow in two red soils from subtropical China
复制标题
通过模拟中国亚热带两种红壤的上坡流入来比较侵蚀和细沟发育过程
DOI：
10.1016/j.catena.2022.106139
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发表时间：
2022-02-21
期刊：
影响因子：
6.2
通讯作者：
Zhang, Wenjie
中科院分区：
文献类型：
--
作者：
Tian, Pei;Gong, Yuwei;Zhang, Wenjie
细沟侵蚀是土壤侵蚀的重要组成部分，但红壤坡面细沟侵蚀的过程和机制尚不清楚。本文利用中国亚热带两种典型的红土：页岩底质土壤（UDS）和第四纪红粘土质底质土壤（UDQ），进行了5种不同入流流量（8.5、10、11.5、13、14.5 L·min(-1)·m(-1)）和1个坡度（8°）的径流冲刷试验。结果表明，对于两种红壤，径流量、产沙率和细沟侵蚀量均与入流量呈线性正相关（p < 0.05）。侵蚀沉积物中沙子含量高、粘土含量低与原始土壤质地（以粘土和粉砂为主）和细沟水流能量密切相关。水流功率和单位水流功率分别是表征 UDS 和 UDQ 细沟侵蚀机制的最佳水力参数。对于粘土含量和容重较高的UDQ，产沙过程更加稳定，侵蚀沉积物中含砂量明显高于UDS，而含泥量明显较低。与UDS相比，UDQ的细沟流速较慢，达西-魏斯巴赫阻力系数较大。对于粘土含量较低、含砂量较高的UDS，平均产沙量和细沟深度分别是UDQ的2.26～4.71和2.79～6.53倍，细沟可蚀性参数是UDQ的1.84倍。研究结果有助于了解亚热带地区细沟侵蚀机制和防止水土流失。
Rill erosion is an important component of soil erosion, however, the process and mechanism of rill erosion on red soil slopes are not clear enough. In this paper, runoff scouring experiments were conducted with five varying inflow rates (8.5, 10, 11.5, 13, 14.5 L min(-1) m(-1)) and one slope (8 degrees) using two typical red soils in subtropical China: Ultisols derived from shale (UDS) and Ultisols derived from quaternary red clay (UDQ). The results showed that for the two red soils, runoff rate, sediment yield rate, and rill erosion amount were all positively correlated with inflow rates in linear relationships (p < 0.05). The high sand and low clay contents in eroded sediments were closely related to the original soil texture (dominated by clay and silt) and rill flow energy. Stream power and unit stream power were the optimal hydraulic parameters to characterize rill erosion mechanisms for UDS and UDQ, respectively. For UDQ with higher clay content and bulk density, the sediment yield process was more stable and the sand content in the eroded sediments was significantly higher than that of UDS, while the silt content was significantly lower. The rill flow of UDQ had slower velocity and larger Darcy-Weisbach resistance coefficient than that of UDS. For UDS with lower clay and higher sand content, the average sediment yield rate and rill depth were 2.26-4.71 and 2.79-6.53 times of UDQ, respectively, and the rill erodibility parameter was 1.84 times that of UDQ. The results are helpful for understanding the rill erosion mechanism and preventing soil loss in subtropical areas.