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干旱区地理 ›› 2022, Vol. 45 ›› Issue (5): 1500-1512.doi: 10.12118/j.issn.1000-6060.2021.597

• 地表过程研究 • 上一篇    下一篇

农田近地表风沙流风程效应变化特征研究

冯哲1(),刘瑞娟1,白宇晨1,常春平1,2,郭中领1,2(),李继峰1,3,王仁德4,李庆4   

  1. 1.河北师范大学地理科学学院,河北 石家庄 050024
    2.河北省环境演变与生态建设实验室,河北 石家庄 050024
    3.河北省环境变化遥感识别技术创新中心,河北 石家庄 050024
    4.河北省科学院地理科学研究所,河北 石家庄 050021
  • 收稿日期:2021-12-13 修回日期:2022-03-21 出版日期:2022-09-25 发布日期:2022-10-20
  • 通讯作者: 郭中领
  • 作者简介:冯哲(1997-),女,硕士研究生,主要从事土壤风蚀研究. E-mail: 1092296157@qq.com
  • 基金资助:
    国家自然科学基金项目(41877066);国家自然科学基金项目(41901001);河北省自然科学基金项目(D2018205192);河北省自然科学基金项目(D2018205212);河北省青年拔尖人才项目(13505197)

Variation characteristics of the fetch effect of near surface aeolian sand flux for farmlands

FENG Zhe1(),LIU Ruijuan1,BAI Yuchen1,CHANG Chunping1,2,GUO Zhongling1,2(),LI Jifeng1,3,WANG Rende4,LI Qing4   

  1. 1. School of Geographical Sciences, Hebei Normal University, Shijiazhuang 050024, Hebei, China
    2. Hebei Key Laboratory of Environmental Change and Ecological Construction, Shijiazhuang 050024, Hebei, China
    3. Hebei Technology Innovation Center for Remote Sensing Identification of Environmental Change, Shijiazhuang 050024, Hebei, China
    4. Institute of Geographical Sciences, Hebei Academy of Sciences, Shijiazhuang 050021, Hebei, China
  • Received:2021-12-13 Revised:2022-03-21 Online:2022-09-25 Published:2022-10-20
  • Contact: Zhongling GUO

摘要:

风沙流的风程效应研究是定量获取风沙流沿程变化的核心和难点,风程效应是指输沙率随沙床表面或地块长度的增加而不断增大,而后趋于稳定的变化特征,饱和输沙率(fmax)和饱和路径长度(Lsat)是风程效应的重要参数。采用自动连续称重式集沙仪,以河北坝上地区康保县境内典型旱作农田为研究对象,观测了2017、2018年和2021年内4次典型风蚀事件,分析近地表5 cm高度风沙流的风程效应在5 min时间尺度下的变化特征。结果表明:(1) 近地表输沙通量随风程距离的增大而增大。(2) 4次风蚀事件中Lsat的变化范围在11~280 m之间,并存在明显差异,其变化与风速无关。(3) 近地表风沙流的fmax与风速(U)呈幂函数关系。(4) 风程效应的变化特征与地表可蚀性因子、地表微地貌变化有着紧密联系,未来应对不同的土壤类型和质地农田的风程效应进行深入研究。

关键词: 土壤风蚀, 风程效应, 饱和输沙率, 饱和路径长度

Abstract:

The fetch effect in aeolian sand transport is a cornerstone for wind erosion modeling and sand dune evaluation. The fetch effect refers to an increase in aeolian sand transport with downstream distance over an eroding surface. The maximum sand flux (fmax) and corresponding critical fetch length (Lsat) are the primary parameters related to the fetch effect. In this paper, a cyclone type instantaneous weighing aeolian sand trap (CCST) was used to observe four typical wind erosion events in 2017, 2018, and 2021 in two farmland regions of Kangbao County, Hebei Province, China. We analyzed the 5 min characteristics of the fetch effect of sand flux at a height of 5 cm above the ground surface. The results revealed that: (1) The aeolian sand flux near the surface increases with the increase in fetch length. (2) The variations of Lsat for the four wind erosion events range from 11 m to 280 m and were obvious and independent on wind velocity (U). (3) The relationship between fmax and U followed a power-law relationship. (4) The extent of the fetch effect may be related to factors including the soil wind erodibility and surface microrelief. More studies are required to explore how the factors related to soil wind erodibility and surface microrelief affect the fetch effect.

Key words: soil wind erosion, fetch effect, maximum sand flux, critical fetch length