EGU22-1241, updated on 27 Mar 2022
https://doi.org/10.5194/egusphere-egu22-1241
EGU General Assembly 2022
© Author(s) 2022. This work is distributed under
the Creative Commons Attribution 4.0 License.

Study on the Occurrence and Development of Gullies under extreme Rainstorm Conditions

Lijuan Yang1,3, Chunmei Wang1,2,3, Chunmei Zhang1,3, Guowei Pang1,3, Yongqing Long1,3, Lei Wang1,3, Baoyuan Liu4, and Qinke Yang1,3
Lijuan Yang et al.
  • 1College of Urban and Environmental Sciences, Northwest University, Xi’an 710127,China
  • 2State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Yangling 712100,China
  • 3Key Laboratory of Ecohydrology and Disaster Prevention in Arid Regions, National Forestry and Grassland Administration, Xi’an 710048, China;
  • 4Advanced Institute of Natural Science, Beijing Normal University, Zhuhai 519087,China

 Soil erosion seriously damages land resources, which is a global environmental problem. Gully erosion is an important manifestation of soil erosion, in recent years, frequent extreme rainstorms have aggravated the occurrence and development of gully erosion. In order to study the formation and development patterns of newly formed gullies under the condition of climate change, this paper takes the Wangwugou Small Watershed of the Chabagou Watershed on the Loess Plateau in Northern Shaanxi as the research area, and takes the “7·26” extreme rainstorm in Northern Shaanxi Province in 2017 as the main research object based on UAV images, to analyze the occurrence regularity of newly formed gullies, and discuss its development characteristics, its difference with the development of existing gullies before 2017, and its relationship with topographic parameters in the following three years. The results showed that: (1) during the “7·26” extreme rainstorm in Northern Shaanxi, there were 45 newly formed gullies in the Wangwugou Small Watershed, which are about 101 gully/km2, and they could be divided into four categories: slope surface gullies, terraced field gullies, unpaved roadway gullies and bottom gullies. The slope surface gullies were the largest, and the bottom gullies and terraced field gullies were wider and larger in area. Production roads, check dam farmland and sloping farmland are most prone to the occurring of gullies under rainstorm conditions. (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 existing gullies, and 34.48% of the heads of newly formed gully was further advanced, which was 1.32 times of the original existing gullies. The average gully head retreat distance of newly formed gullies is 3 times that of the original existing gullies, which is up to 0.58 m/a, and the maximum speed could reach 2.12 m/a. (3) The increase of the drainage area could significantly promote the development of gully heads, which is an important topographic index to simulate the retreat rate of gully heads. Under extreme rainfall conditions, the soil erosion situation is highly serious in the study area, and the source of newly formed gullies could be traced more rapidly within three years after their occurrence. Therefore, special attention and enhanced management should be attached to the prevention and control of such gullies.

How to cite: Yang, L., Wang, C., Zhang, C., Pang, G., Long, Y., Wang, L., Liu, B., and Yang, Q.: Study on the Occurrence and Development of Gullies under extreme Rainstorm Conditions, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-1241, https://doi.org/10.5194/egusphere-egu22-1241, 2022.