黄土区土质道路浮土侵蚀过程

应用生态学报

黄土区土质道路浮土侵蚀过程

李建明¹,秦伟²,左长清²,王文龙^1,3**,郭明明¹,欧阳潮波¹

(¹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, 陕西杨凌 712100; ^2中国水利水电科学研究院泥沙研究所, 北京 100044; ³中国科学院水利部水土保持研究所, 陕西杨凌 712100)

出版日期:2015-05-18 发布日期:2015-05-18

Processes of earth road regolith erosion in loess area.

LI Jian-ming¹, QIN Wei², ZUO Chang-qing², WANG Wen-long^1,3, GUO Ming-ming¹, OUYANG Chao-bo^1

(¹State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Institute of Soil and Water Conservation, Northwest A＆F University, Yangling 712100, Shaanxi, China; ^2Department of Sedimentation, China Institute of Water Resources and Hydropower Research, Beijing 100044, China; ³Institute of Soil and Water Conservation, Chinese Academy of Sciences and Ministry of Water Resources, Yangling 712100, Shaanxi, China)

Online:2015-05-18 Published:2015-05-18

摘要/Abstract

摘要：

基于野外原位调查采样、室内人工模拟降雨试验研究道路浮土侵蚀规律.结果表明：浮土产流起始时间和路面侵蚀起始时间随雨强和坡度增大呈递减趋势.路面侵蚀起始时间随浮土厚度增大滞后2~5 min.浮土厚度≤0.5 cm时径流率在产流后2 min趋于稳定，平均径流率随雨强增大而递增，随坡度增大而递减；浮土厚度≥1.0 cm时，径流率在产流后3 min趋于相对稳定，平均径流率随雨强增大呈线性递增，随坡度增大而先递增后递减.侵蚀临界点随坡度和雨强增大呈递减趋势.浮土厚度≤0.5 cm时，侵蚀速率随雨强增大而递增幅度达24.5%~434.4%，坡度8°和16°可达2°和4°的2.4倍；浮土厚度≥1.0 cm时，侵蚀速率在产流开始后9 min左右趋于相对稳定，且随雨强和坡度增大而递增，随坡度增大侵蚀形式发生由“片蚀-细沟侵蚀-溯源侵蚀”的转变.浮土厚度≥1.0 cm时，平均10 min次降雨侵蚀量可达浮土厚度≤0.5 cm的1.3倍，而单独浮土侵蚀时段侵蚀量前者是后者的2.7倍.浮土厚度≤0.5 cm时，侵蚀量与雨强的相关性显著，产流量与坡度的相关性显著；浮土厚度≥1.0 cm时，10 min次降雨产流、产沙与雨强呈显著相关.随浮土厚度增大，浮土侵蚀量在组合侵蚀中所占比例增大，而薄层时主要以道路侵蚀占主导.

Abstract: Based on field investigation, the processes of earth road regolith erosion were studied under indoor simulated rainfall. Results showed that the runoff initiation time for both regolith and earth road surface erosion decreased with the increasing rainfall intensity and slope steepness. With the increase in regolith thickness, the initiation time for earth road surface erosion lagged for 2-5 min. When the regolith thickness was ≤0.5 cm, the runoff rate turned to be stable at 2 min after runoff generation, and the average runoff rate increased with the increasing rainfall intensity and decreased with the increasing slope steepness. When the regolith thickness was ≥1.0 cm, runoff rate turned to be stable at 3 min after runoff generation, and the average runoff rate increased linearly with the rainfall intensity but exhibited a gradually decreasing trend after the first increment with the increasing slope steepness. The critical point for regolith erosion decreased with the increasing rainfall intensity and slope steepness. With the regolith thickness of ≤0.5 cm, the erosion rate increased with the increasing rainfall intensity, with the erosion rate ranging from 24.5% to 434.4%, and the erosion rates for 8° and 16° slopes were 2.4 times as those for 2° and 4° slopes. With the regolith thickness of ≥1.0 cm, the erosion rate turned to be stable about 9 min after runoff generation and increased with the increasing rainfall intensity and slope. With the increasing slope steepness, the erosion form changed from sheet erosion to rill erosion and then to headward
erosion. The average erosion amount over 10 min single rainfall for the regolith thickness of ≥1.0 cm was 1.3 times as that for the regolith thickness of ≤0.5 cm, while it was 2.7 times as that at the stage of regolith erosion alone. With the regolith thickness of ≤0.5 cm, the erosion amount had a significant correlation with rainfall intensity, and runoff volume with slope steepness. With the regolith thickness of ≥1.0 cm, both runoff and sediment yields in 10 min single rainfall had a significant correlation with rainfall intensity. The proportion of regolith erosion to the combined erosion increased with the increasing regolith thickness, while the road erosion was the main form at small regolith thickness.

李建明1,秦伟2,左长清2,王文龙1,3**,郭明明1,欧阳潮波1. 黄土区土质道路浮土侵蚀过程[J]. 应用生态学报.

LI Jian-ming1, QIN Wei2, ZUO Chang-qing2, WANG Wen-long1,3, GUO Ming-ming1, OUYANG Chao-bo1. Processes of earth road regolith erosion in loess area.[J]. Chinese Journal of Applied Ecology.