LI Yang, ZHANG Jianjun, WEI Guangkuo, et al. Investigation of Shallow Landslide After Extreme Rainfall and Analysis of Its Influencing Factors in the West Shanxi Loess Region[J]. 2022, 36(5): 44-50.
DOI:
LI Yang, ZHANG Jianjun, WEI Guangkuo, et al. Investigation of Shallow Landslide After Extreme Rainfall and Analysis of Its Influencing Factors in the West Shanxi Loess Region[J]. 2022, 36(5): 44-50. DOI: 10.13870/j.cnki.stbcxb.2022.05.007.
Investigation of Shallow Landslide After Extreme Rainfall and Analysis of Its Influencing Factors in the West Shanxi Loess Region
Shallow landslides caused by extreme rainfall have resulted in serious environmental damage and losses. In order to explore the effects of land use
vegetation types and topographic factors on shallow landslides under extreme rainfall conditions
this study conducted a field investigation on shallow landslides caused by extreme rainfall from October 3 to 6
2021 in Caijiachuan Watershed of Ji County
Shanxi Province
and analyzed the characteristics and process of extreme rainfall
the number and damaged area of shallow landslide under different land uses
vegetation and terrain conditions. The results showed that: (1) The extreme rainfall was 31.2% of the annual average rainfall
reaching 161.3 mm
the duration of rainfall was 84 hours
the peak rainfall intensity was 7 mm/h
the average rainfall intensity was 2.1 mm/h
and the frequency of rainfall of this degree was 0.16%. (2) A total of 479 shallow landslides occurred in the small watershed of farmland
plantation and secondary forest in Caijiachuan basin
with the damage area of 183 881 m2
and 90% of the shallow landslide area was less than 885 m2. (3) The number and damage area of shallow landslides per unit area were as follows: small watershed of agricultural land (214 /km2 and 109 241 m2/km2) > small watershed of plantation forest (163 /km2 and 48 779 m2/km2) > small watershed of secondary forest (42 /km2 and 17 176 m2/km2). At the small watershed scale
the effect of forest vegetation on shallow landslide prevention was significantly higher than that of agricultural land
and the effect of secondary forest was better than that of artificial forest. (4) The slope of shallow landslide was 10°~80°
the number of shallow landslide and the damaged area increased with the increases of slopes
and reached the peak in the range of 40°~50°. When the slope was greater than 50°
the number of shallow landslide and the damaged area decreased with the increases of slopes. Slope was the dominant factor affecting shallow landslide. (5) Shallow landslides mainly occurred on the slope with slope aspect of 22.5°~337.5°. The number and damage area of shallow landslides did not show obvious regularity with slope aspect
and slope aspect had little influence on shallow landslides.
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