砒砂岩区典型淤地坝沉积泥沙特征及来源分析  

Sediment Characteristics and Sources Analysis of Typical Check Dam in Pisha Sandstone Area

作　　者：蒋凯鑫 于坤霞[1,2] 李鹏[1,2] 李占斌[1,2,3] 白璐璐[1,2] 谢梦瑶 刘昱 JIANG Kaixin;YU Kunxia;LI Peng;LI Zhanbin;BAI Lulu;XIE Mengyao;LIU Yu(State Key Laboratory of Eco-hydraulics in Northwest Arid Region of China,Xi’an University of Technology,Xi’an 710048;Key Laboratory of National Forestry Administration on Ecological Hydrology and Disaster Prevention in Arid Regions,Xi’an University of Technology,Xi’an 710048;State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau,Institute of Soil and Water Conservation,CAS&MWR,Yangling,Shaanxi 712100)

机构地区：[1]西安理工大学省部共建西北旱区生态水利国家重点实验室,西安710048 [2]西安理工大学旱区生态水文与灾害防治国家林业局重点实验室,西安710048 [3]中国科学院水利部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

出　　处：《水土保持学报》2020年第1期47-53,共7页Journal of Soil and Water Conservation

基　　金：国家重点研发计划项目(2016YFC0402404,2016YFC0402407);国家自然科学基金项目(41330858)

摘　　要：黄土高原地区的淤地坝是拦减入黄泥沙的关键措施,尤以对泥沙具有绝对控制的"闷葫芦"淤地坝为甚。为研究淤地坝对侵蚀泥沙的拦蓄作用,以砒砂岩区皇甫川流域园子沟淤地坝为研究对象,采集坝地淤积剖面及沟间地、沟谷地表层样品,对沉积旋回进行断代分析,计算泥沙贡献率,反演其淤积过程。结果表明:坝地沉积泥沙粒径分布以2~0.05 mm砂粒为主,其次为粉粒、黏粒,砂粒中以极细砂和细砂占比最多。园子沟坝控流域内侵蚀性降雨事件对应的最小日降雨量为22.8 mm;淤地坝运行可划分为2个阶段,前期主要依靠坝体拦蓄泥沙,后期随着拦蓄泥沙的增多,减蚀作用凸显。坝地沉积泥沙主要来源为沟谷地,贡献率达71.4%,沟间地为28.6%,其中沟间地侵蚀产沙并非受植被唯一影响,在降雨量>45.4 mm时,地形因素会限制侵蚀的加剧。In the Loess Plateau, as the significant measure for preventing and reducing the sediment into the Yellow River, check dams are playing an essential role in sediment retention and farmland-making. In order to study the effect of check dam on the changes of soil erosion, sediment yield and sources in dam-controlled watershed, a check dam named Yuanzigou in Huangfuchuan watershed of Pisha sandstone area was selected as the research object. The soil samples were collected on the check dam profile and the surface of the slopes including land between gullies and gully region. The sediment deposition records of sediment couplets were analyzed by identifying the relationship between rainfall events and sediment couplets. The sediment sources were assessed and the changes of the sediment yield intensity were analyzed. The particle size analysis indicated that the sediment particle size distribution of the sediment profiles in the check dam mostly concentrated in the range of 0.05~2 mm sand, in which the proportion of very fine sand and fine sand was the most, followed by silt and clay. According to the corresponding relationship between rainfall events and sediment couplets, the minimum daily rainfall corresponding to erosive rainfall events in the dam-controlled watershed was 22.8 mm. And the sediment deposition process was divided into 2007-2013 and 2013-2016. In the early stage, it mainly depended on the dam body to trap sediment, and in the later stage, as more sediment is trapped the effect of erosion reduction was prominent. The results of sediment contribution analysis indicated that 71.4% of the sediment was contributed by the gully region and 28.6% by land between gullies. The erosion and sediment yield of land between gullies were not only affected by vegetation. When the daily rainfall was more than 45.4 mm, topographic factor would limit the the further occurrence of erosion.

关 键 词：皇甫川流域 淤地坝 侵蚀性降雨 沉积旋回 泥沙贡献率 

分 类 号：S157.1[农业科学—土壤学]