杨丽娟, 王春梅, 张春妹, 庞国伟, 龙永清, 王雷, 刘宝元, 杨勤科. 基于遥感影像研究极端暴雨条件下新成切沟发生发展规律[J]. 农业工程学报, 2022, 38(6): 96-104. DOI: 10.11975/j.issn.1002-6819.2022.06.011
    引用本文: 杨丽娟, 王春梅, 张春妹, 庞国伟, 龙永清, 王雷, 刘宝元, 杨勤科. 基于遥感影像研究极端暴雨条件下新成切沟发生发展规律[J]. 农业工程学报, 2022, 38(6): 96-104. DOI: 10.11975/j.issn.1002-6819.2022.06.011
    Yang Lijuan, Wang Chunmei, Zhang Chunmei, Pang Guowei, Long Yongqing, Wang Lei, Liu Baoyuan, Yang Qinke. Occurrence and development of newly formed gullies under extreme rainstorm conditions using remote sensing images[J]. Transactions of the Chinese Society of Agricultural Engineering (Transactions of the CSAE), 2022, 38(6): 96-104. DOI: 10.11975/j.issn.1002-6819.2022.06.011
    Citation: Yang Lijuan, Wang Chunmei, Zhang Chunmei, Pang Guowei, Long Yongqing, Wang Lei, Liu Baoyuan, Yang Qinke. Occurrence and development of newly formed gullies under extreme rainstorm conditions using remote sensing images[J]. Transactions of the Chinese Society of Agricultural Engineering (Transactions of the CSAE), 2022, 38(6): 96-104. DOI: 10.11975/j.issn.1002-6819.2022.06.011

    基于遥感影像研究极端暴雨条件下新成切沟发生发展规律

    Occurrence and development of newly formed gullies under extreme rainstorm conditions using remote sensing images

    • 摘要: 土壤侵蚀严重破坏土地资源,是全球性的环境问题,切沟侵蚀是土壤侵蚀的重要表现形式,近年来极端暴雨频发加剧了切沟侵蚀的发生和发展。为了研究气候变化条件下新成切沟的形成与发育规律,该研究以陕北子洲岔巴沟流域王武沟小流域为研究区,基于无人机航摄影像,以2017年陕北"7·26"暴雨新成切沟为研究对象,分析新成切沟发生规律,并探讨在之后的3 a中其发育特征、与原有切沟发育的差异性及其与地形参数的关系。结果表明:1)在"7·26"暴雨中,王武沟发育新成切沟45条,约101条/km2,可分为坡面切沟、梯田切沟、道路切沟和底部切沟四类,以坡面切沟最多,底部切沟和梯田切沟总体更宽、面积更大;生产道路、淤地坝和坡耕地在暴雨条件下是最容易发生切沟的地块;2) 新成切沟在形成之后的3 a内沟头发育较原有切沟更为迅速。34.48%的新成切沟沟头进一步前进,这一数值为原有切沟的1.32倍;新成切沟前进距离均值是原有切沟的3倍,达0.58 m/a;3)汇水面积增加可显著促进切沟沟头发育,是模拟切沟沟头前进速率的重要地形指标。可见,极端降雨条件下研究区土壤侵蚀严重,新成切沟发生之后的3 a内溯源尤为迅速,应给予特别关注,加强对这类切沟的预防与治理。

       

      Abstract: Abstract: Soil erosion has posed some serious damage on the land resources in the world. The "Grain for Green" project in 1999 has been launched to restore the vegetation on the steep slope farmlands and control the soil and water loss for a better ecological environment of the Loess Plateau in China. But, the frequent extreme rainstorms have aggravated the occurrence and development of gully erosion under global warming in recent years. The development of the gullies after the extreme rainstorm still remains unclear so far. Fortunately, the Unmanned Aerial Vehicle (UAV) data can be collected fast, accurately, and efficiently after a rainstorm. The flexible acquisition time of UAVs can be expected to serve as an effective tool for the development of gully. Taking the Wangwugou Small Watershed of Chabagou Watershed on the Loess Plateau as the research area, this study aims to investigate the formation and development of gully under a rainstorm using UAV images. A case study selected the "7·26" extreme rainfall that occurred in Northern Shaanxi of China on July 26, 2017, with a daily rainfall of 206.6 mm. The patterns of newly formed gullies were captured under the climate. An equation with the topographic parameters was established for the occurrence and development of newly formed gullies in the following three years. The results showed that: 1) There were 45 newly formed gullies during the extreme rainstorm, which were about 101 gully/km2 in total. Four types were divided, including the hill slope, terraced field, unpaved roadway, and bottom gullies. There were more gullies found on the slopping hills. The bottom and terraced field gullies presented much wider and larger in the study area. The unpaved roads, check dam farmland, and sloping farmland were more prone to the gullies. 2) In the three years after the formation of the new gullies, the development of the new gully heads was faster than that of the original, 34.48% of which were further advanced, indicating 1.32 times the original. The average gully head retreat rate of newly formed gullies was three times that of the original, up to 0.58 m/a, where the maximum speed reached 2.12 m/a. 3) The drainage area significantly promoted the development of gully heads. A critical topographic index was selected to simulate the retreat rate of gully heads. There was more severe soil erosion under extreme rainfall conditions. The source of newly formed gullies was rapidly traced within three years after the occurrence. Therefore, the appropriate management can be attached to prevent such gullies during this time. This finding can provide an essential reference to estimate the rill erosion on the different types of sloping land in the hilly area of Loess Plateau.

       

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