摘要
为探明三峡水库土质消落带土壤物理性质对反复淹水的响应,选取消落带代表性土壤紫色土,以180m处未淹水土壤为对照,分析了土壤基本物理性质在消落带上的分布规律及其对淹水的响应规律。结果表明:表层土的基本物理性质对淹水响应最为强烈。随水位高程增加,土壤容重逐渐降低,最大降幅16.42%;淹水后土壤容重显著增加,最大增幅达38.42%。孔隙率整体呈先降低后增高的趋势,在160m处出现最小值40.77%;淹水后孔隙率显著降低,最大降幅达35.10%。颗粒组成呈低水位段粗、高水位段细,表层粗、下层细的特征分布;随水位高程增加,粗颗粒(砂粒)的体积百分比和中值粒径均减小,降幅分别为40.47%和52.99%;淹水后砂粒含量和中值粒径均显著增加,最大增幅达91.60%和141.72%。同一时期黏聚力在消落带以先增高后降低的趋势分布,最大变化幅度达195.76%,淹水前后黏聚力最大变化幅度达163.24%;内摩擦角的分布随水位高程变化较小,淹水前后内摩擦角最大变化幅度达54.42%。本文研究结果可为消落带土壤侵蚀机理研究和科学防治提供参考。
The purple soil of Three Gorges Reservoir region water-level fluctuation zone was selected to explore the response of soil physical properties to repeated flooding.The distribution pattern of soil physical properties and their response to water flooding were analyzed and compared with the non-flooded soil at 180 m.Soil samples were collected in two layers of 10 cm each for analysis.The results showed that the strongest influence on the topsoil was observed due to flooding.The soil bulk density decreased with an increase in elevation of water level,and the maximum decrease in the soil bulk density was 16.42%.After impounding,the soil bulk density increased significantly,and the maximum increase in soil bulk density was 38.42%.The soil porosity reached to the lowest point(40.77%)at 160 m.Flooding significantly reduced the porosity,and it reached its lowest point of 35.10%.The grain composition became coarser with the decrease of the water elevation level and soil layer.With the increase of elevation of the water level,percentage volume of coarse particles gradually decreased for the two layers,and decreased by 40.47%and 52.99%,respectively.Flooding had positive effects on the percent volume of sand and median diameter,and the maximum value of sand increased by 91.60%and 141.72%for the two layers,respectively.The cohesion presented the unimodal curve along the water-level fluctuation during the same period,the maximum amplitude of variation was 195.76%.Flooding resulted in the increase of soil cohesion,the maximum variation was 163.24%.There was no significant distinction in internal friction angle with elevation changes.Flooding altered the internal friction angle,and its maximum value reached to 54.42%.The results of the present study can be used as the references for analyzing the mechanism of soil erosion and controlling the soil erosion.
作者
吕发友
唐强
张淑娟
贺秀斌
鲍玉海
LYU Fayou;TANG Qiang;ZHANG Shujuan;HE Xiubin;BAO Yuhai(Key Laboratory of Mountain Surface Processes and Ecological Regulation,Institute of Mountain Hazards and Environment,Chinese Academy of Sciences,Chengdu 610041,China;University of Chinese Academy of Sciences,Beijing 100049,China)
出处
《水土保持研究》
CSCD
北大核心
2018年第1期276-281,共6页
Research of Soil and Water Conservation
基金
国家自然科学基金项目(41571278)
中国科学院科技服务网络计划项目(KFJ-SW-STS-175)
中国科学院"西部之光"人才培养引进计划(2013&2016)
关键词
三峡水库
消落带
紫色土
物理性质
反复淹水
Three Gorges Reservoir
water-level fluctuation zone
physical properties
repeated flooding
