地理学报 ›› 2018, Vol. 73 ›› Issue (1): 81-91.doi: 10.11821/dlxb201801007

• 地表过程与生态环境 • 上一篇    下一篇

官坝河泥石流发育特征及对四川邛海的泥沙淤积效应

魏学利1,2(),陈宁生3   

  1. 1. 中国气象局乌鲁木齐沙漠气象研究所,乌鲁木齐 830002
    2. 新疆维吾尔自治区交通规划勘察设计研究院,乌鲁木齐 830006
    3. 中国科学院水利部成都山地灾害与环境研究所,成都 610041
  • 收稿日期:2017-04-12 出版日期:2018-01-31 发布日期:2018-01-31
  • 基金资助:
    中国沙漠气象科学研究基金项目(Sqj2015015);国家自然科学青年基金项目(41602331);中国博士后科学基金项目(2016M602951XB)

Development of debris flows in Guanba River and its effect on sediment deposition in Qionghai Lake of Sichuan

WEI Xueli1,2(),CHEN Ningsheng3   

  1. 1. Institute of Desert Meteorology, CMA, Urumqi 830002, China
    2. Academy of Transportation planning Surveying and Design, Urumqi 830006, China
    3. Institute of Mountain Hazards and Environment, CAS, Sichuan, Chengdu 610041, China
  • Received:2017-04-12 Online:2018-01-31 Published:2018-01-31
  • Supported by:
    Desert Climatic Science Research Foundation of China, No.Sqj2015015;National Science Foundation for Young Scholars of China, No.41602331;Postdoctoral Science Foundation of China, No.2016M602951XB

摘要:

晚新生代以来青藏高原的强烈隆升造成青藏高原东南边界形成大量的构造断裂,同时构造拉伸和挤压作用也塑造了许多构造断陷湖泊。近年来很多湖泊的面积和深度逐渐减小,对当地生态环境和社会经济发展带来极大影响。选取青藏高原东南缘的西昌邛海流域为研究区,探讨邛海北岸官坝河泥石流发育特征及对邛海的泥沙淤积效应。研究发现:① 官坝河泥石流暴发频率高且规模大,崩塌滑坡和面源侵蚀是泥石流最主要的固体物质来源,动储量约为428.03万m3;② 山洪泥石流的频繁发生是邛海泥沙淤积的主要原因,而频繁地震和强降雨耦合作用控制着区域山洪泥石流活动,预测邛海流域泥石流活动仍将频繁发生,泥沙淤积问题更加严重;③ 自1950年以来,邛海流域泥沙淤积速率约为17.09 mm/a,如按当前淤积速率推算,邛海的寿命将仅约为600年左右;④ 建议对官坝河流域实施工程治理和生物防护相结合的综合治理,并加强流域管理和宣传培训等行政法治管理。该成果可为邛海流域综合规划管理和防灾减灾提供参考依据,有助于揭示青藏高原东南缘湖泊逐渐萎缩的真正原因和控制要素。

关键词: 青藏高原, 西昌官坝河, 泥石流, 四川邛海, 泥沙淤积, 构造断陷湖泊

Abstract:

Since the late-Cenozoic, the strong uplift of Tibetan Plateau not only formed a large number of tectonic fractures on the southeast edge, but also generated many tectonic rift lakes due to structural stretching and compression. However, in recent years, some of the lakes started to shrink and depicted a reduction in lake depth, which has eventually exerted great influence on local ecological environment and socio-economic development. In this paper the Qionghai Lake, located on the southeast edge of the Tibetan Plateau, is selected as the study area. Based on exploring the debris flow characteristics of Guanba river in the north of Qionghai Lake, the effect of sediment deposition deriving from debris flows on Qionghai Lake is analyzed. The research shows that: (1) The scale and frequency of debris flow occurrence is higher in the Guanba River, and the primary material sources are landslide and non-point source erosion with a movable volume of 428.03×104 m3. (2) The frequent occurrence of floods and debris flows are the primary cause of sediment accumulation in the Qionghai Lake, and the debris flows are controlled by the coupling effect of frequent earthquakes and heavy rainfall. It is predicted that debris flows will still occur frequently, and sedimentation disasters will become more severe in the future. (3) Since 1950, the average deposition rate was about 17.09 mm/a. In terms of current deposition rate, it is inferred that the longevity of the Qionghai Lake will be only about 600 years. (4) The comprehensive governance model with management of administrative law is proposed in the Guanba River. The results can not only provide reference bases for planning management and disaster prevention in Qionghai Lake basin, but also contribute to reveal the reason of lake shrinkage on the southeast edge of Tibetan Plateau.

Key words: Tibetan Plateau, Guanba River in Xichang, debris flows, Qionghai Lake in Sichuan, sediment deposition, tectonic rift lake