首页 | 本学科首页   官方微博 | 高级检索  
     

黄土高原北部丘陵沟壑区近160年土壤侵蚀量演变及其对ENSO事件的响应
引用本文:王夏青,夏梦婷,许建伟,彭保发,唐湘玲. 黄土高原北部丘陵沟壑区近160年土壤侵蚀量演变及其对ENSO事件的响应[J]. 地理科学, 2019, 39(7): 1174-1183. DOI: 10.13249/j.cnki.sgs.2019.07.016
作者姓名:王夏青  夏梦婷  许建伟  彭保发  唐湘玲
作者单位:湖南文理学院资源环境与旅游学院,湖南常德415000;洞庭湖生态经济区建设与发展湖南省协同发展中心,湖南常德415000;湖南文理学院资源环境与旅游学院,湖南常德,415000;桂林理工大学地球科学学院,广西桂林,541004
基金项目:国家自然科学基金项目(41807390);黄土与第四纪地质国家重点实验室开放基金课题(SKLLQG1832);湖南省教育厅科研项目(17C1075);湖南文理学院博士科研启动基金项目资助(E07017015)
摘    要:对形成于1851~1861年的靖边(JB)聚湫内22.75 m沉积序列进行完整钻探,并基于XRF Core Scanning的元素分布划分旋回和年际冻融层,在高精度定年的基础上计算旋回及年际产沙量和产沙模数。结果表明:JB聚湫沉积序列由126个旋回叠加而成,且形成于1855~2014年的78 个年份中。JB聚湫内旋回产沙量和产沙模数变化范围分别为0.27×10 4~22.44×10 4t和0.09×10 4~7.82×10 4t/km 2;年际产沙量和产沙模数范围分别为0.27×10 4~90.73×10 4t/a和0.09×10 4~23.40×10 4t/(km 2·a)。 ENSO事件显著影响JB流域强降水作用下的侵蚀产沙,且在El Ni?o次年和La Ni?a年份发生侵蚀产沙的频率较高,可能是这些年份中东亚季风增强后带来更多强降水事件的结果。研究结果有效延长了黄土高原北部丘陵沟壑区小流域土壤侵蚀演变历史,充分理解ENSO事件驱动下该地区侵蚀产沙的响应,为黄土高原北部坝库建设、水土流失治理和防洪减灾等提供理论依据。

关 键 词:沉积旋回  年际冻融层  土壤侵蚀  聚湫  ENSO事件
收稿时间:2018-09-08
修稿时间:2018-11-02

Erosion Flux Change and Its Response to ENSO Events During the Past 160 Years Within the Hill-gully Area at the Northern Loess Plateau
Wang Xiaqing,Xia Mengting,Xu Jianwei,Peng Baofa,Tang Xiangling. Erosion Flux Change and Its Response to ENSO Events During the Past 160 Years Within the Hill-gully Area at the Northern Loess Plateau[J]. Scientia Geographica Sinica, 2019, 39(7): 1174-1183. DOI: 10.13249/j.cnki.sgs.2019.07.016
Authors:Wang Xiaqing  Xia Mengting  Xu Jianwei  Peng Baofa  Tang Xiangling
Affiliation:College of Resources and Environment and Tourism, College of Hunan Arts and Science, Changde 415000, Hunan, China
Hunan Province Cooperative Innovation Center for the Construction & Development of Dongting Lake Ecological Economic Zone, Changde 415000, Hunan, China;
Institute of Earth Science, Guilin University of Technology, Guilin 541004, Guangxi, China
Abstract:As one of the most severe soil erosion areas and typical fragile eco-environment regions, the soil erosion processes on the Chinese Loess Plateau (CLP) include surface soil erosion and weathering, hydrological transport and biological activities in the catchment, all of which belong to the processes of Earth’s Critical Zone. Nevertheless, the understanding of historical soil erosion flux and its driving mechanism is limited, which significantly restricts the reasonable evaluation of erosion control effect on the CLP since 1950s. The sediment sequences in the check dams and landslide-dammed reservoirs on the CLP, which are composed of different numbers of deposition couplets and annual freeze-thaw layers, are one of the best geological carriers for high-resolution reconstructing historical erosion flux, storm intensity and frequency, eco-environment change and land use. Located at the hilly-gully area of the northern Loess Plateau, Jingbian (JB) landslide-dammed reservoir was the result of natural collapse of loess slope at the left of the gully during the period of 1851-1861, which had conserved erosion sediments and documented natural and human information in the catchment during the past 160 years. Based on a drilled 22.75 m JB sediment sequence, Rb/Zr ratios by XRF core scanning and correlation between Ca/Zr and Fe/Zr were used to plot deposition couplets and identify annual freeze-thaw layers. Meanwhile, couplets and annual (specific) sediment yields were calculated when the chronology of the JB sequence was built by the combination of 137Cs contents, annual freeze-thaw layers, modern and history rainfall records. The results showed that the JB sediment sequence consisted of total 126 couplets with 78 annual freeze-thaw layers, which were formed between 1855 and 2014. The range of couplet sediment yields and specific sediment yields in the JB catchment were 0.27×10 4-22.44×10 4t and 0.09×10 4-7.82×10 4t/km 2, respectively. And the range of annual sediment yields and specific sediment yields were 0.27×10 4-90.73×10 4t/a and 0.09×10 4-23.40×10 4t/(km 2·a), respectively. ENSO events significantly affected soil erosion and sediment yield under heavy rains in the JB catchment. Further, compared with El Ni?o years, the sediments in the JB catchment was more prone to be eroded and deposited in the La Ni?a years and next years of El Ni?o, which may be mainly contributed on the heightened East Asian monsoon along with more precipitations within the JB catchment in these years. These results are helpful for extending the history of soil erosion flux in the small catchments and for understanding the response of soil erosion for ENSO events at the hilly-gully area, which will provide the theory basis for dam construction, soil and water loss management, flood control on the northern CLP.
Keywords:deposition couplets  annual freeze-thaw layers  soil erosion  landslide-dammed reservoirs  ENSO events  
本文献已被 万方数据 等数据库收录!
点击此处可从《地理科学》浏览原始摘要信息
点击此处可从《地理科学》下载全文
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号