黄土区土质与土石质塿土堆积体水力侵蚀过程差异  

Differences in hydraulic erosion processes of the earth and earth-rock Lou soil engineering accumulation in the Loess Region

作　　者：纪丽静 王文龙 康宏亮[1] 赵满 郭明明 白芸 速欢 聂慧莹 JI Li-jing;WANG Wen-long;KANG Hong-liang;ZHAO Man;GUO Ming-ming;BAI Yun;SU Huan;NIE Hui-ying(State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateaus,Institute of Soil and Water Conservation,Northwest A&F University,Yangling 712100,Shaanxi,China;Institute of Soil and Water Conser-vation,Chinese Academy of Sciences&Ministry of Water Resources,Yangling 712100,Shaanxi,China;Key Laboratory of Ecological Rehabilitation of Northern Shaanxi Mining Area,Yulin Univer-sity,Yulin 719000,Shaanxi,China).)

机构地区：[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试验室,陕西杨凌712100 [2]中国科学院水利部水土保持研究所,陕西杨凌712100 [3]榆林学院陕西省陕北矿区生态修复重点实验室,陕西榆林719000

出　　处：《应用生态学报》2020年第5期1587-1598,共12页Chinese Journal of Applied Ecology

基　　金：国家重点研发计划项目(2016YFC0501604);国家自然科学基金项目(41701316,41761062,40771127)资助。

摘　　要：利用室内模拟降雨试验,研究了不同雨强及坡度条件下黄土区土质(不含砾石)与土石质(砾石质量分数30%)塿土堆积体的水动力学特征、侵蚀特征及侵蚀动力机制的差异。结果表明:砾石存在改变了堆积体坡面的水动力学特性,与土质坡面相比,土石质坡面的流速、弗汝德数、单位径流功率和过水断面单位能分别减少1.7%~49.7%、6.7%~60.6%、2.0%~44.6%和1.0%~26.7%;曼宁糙率系数、径流剪切力分别增加6.2%~169.4%、5.7%~79.3%。2.0、2.5 mm·min-1雨强下,土石质坡面侵蚀速率较土质坡面降低26.2%~89.9%,砾石的减沙效益显著。2种堆积体的侵蚀速率与水动力学参数间均可用线性函数拟合,与土质坡面相比,土石质坡面的可蚀性参数均降低,降幅为56.1%~73.3%;而临界水动力学参数中径流剪切力增加11.1%,径流功率、单位径流功率和过水断面单位能分别减少25.4%、64.0%和5.0%。砾石的存在一定程度上控制了工程堆积体坡面降雨侵蚀过程。An indoor rainfall simulation experiment was conducted to examine the hydrodynamic characteristics, erosion characteristics, and erosion dynamics mechanisms of earth(excluding gra-vel) and earth-rock(gravel mass fraction 30%) Lou soil engineering accumulation in the Loess area across different rainfall intensities and slope gradients. Results showed that the presence of gravel changed the hydrodynamic characteristics of the engineering accumulation slope. The flow velocity, froude number, unit stream power, and unit energy of water-carrying section of the earth-rock slope were 1.7%-49.7%, 6.7%-60.6%, 2.0%-44.6% and 1.0%-26.7% lower than those of the earth slope, while the Manning roughness coefficient and runoff shear stress of the earth-rock slope were 6.2%-169.4% and 5.7%-79.3% higher than those of the earth slope respectively. Under the intensity of 2.0 and 2.5 mm·min-1, erosion rate of the earth-rock slope was 26.2%-89.9% lower than that of earth slope. The gravel significantly reduced slope erosion of the Lou soil engineering accumulation. Erosion rate and hydrodynamic parameters of the two accumulations were linearly related. The erodibility parameters of earth-rock slope were 56.1%-73.3% lower than that of earth slope. In the critical hydrodynamic parameters, runoff shear stress of earth-rock slope was 11.1% higher, while the stream power, unit stream power and unit energy of water-carrying section were 25.4%, 64.0% and 5.0% lower than those of the earth slope, respectively. The existence of gravel controlled rainfall erosion process on the slope of the engineering accumulation to some extent.

关 键 词：塿土堆积体 水动力学特性 产沙特征 侵蚀动力机制 

分 类 号：S157.1[农业科学—土壤学]