基于过程降雨的红层丘陵低山区滑坡灾害气象预警阈值研究

[目的] 研究不同历时降雨强度与区域滑坡灾害的关系，并对滑坡灾害的气象预警阈值进行研究，为地方管理部门地质灾害预警提供科学依据。 [方法] 收集了2013—2021年研究区348个雨量站的逐小时降雨数据和231处近10 a已发生灾情、险情滑坡事件的时间及位置，基于平均降雨强度(I)—降雨历时(D)模型，分地貌单元，提出了不同降雨历时的临界降雨预警阈值和分级预警阈值。 [结果] 研究区丘陵地貌区不同前期降雨条件下1，3，6，12，24和48 h平均雨强的红色预警阈值依次为29.774，18.579，14.416，11.186，8.679和6.734 mm；低山地貌区不同前期降雨条件下1，3，6，12，24和48 h平均雨强的红色预警阈值依次为28.849，15.542，10.520，7.121，4.820和3.263 mm。 [结论] 在24 h前期降雨条件下，低山区对降雨的敏感性明显比丘陵区高，具体表现为低山区1，3，6，12和24 h的临界预警阈值明显比丘陵区更低，但随着降雨历时进一步延长，低山区和丘陵区域临界预警阈值趋于相近。

Meteorological Warning Thresholds for Regional Landslide Disasters in Red Bed Hills at Low Mountain Area Based on Process Rainfall

[Objective] The relationship between rainfall intensity of different durations and regional landslide disasters was studied, and the meteorological warning threshold of landslide disasters was determined in order to provide a scientific basis of geological disaster warnings for local administrative departments. [Methods] Hourly rainfall data from 348 rainfall stations in the study area during 2013—2021 were collected, as well as the time and location of 231 disaster and dangerous landslide events that have occurred in the past 10 years. Based on the average rainfall intensity (I)—rainfall duration (D) model, the dataset was divided into geomorphic units. Critical rainfall warning thresholds were proposed, and graded warning thresholds for different rainfall durations were determined. [Results] Red warning thresholds for the average rainfall intensity at 1, 3, 6, 12, 24, and 48 hours under different early rainfall conditions in the hilly terrain area of the study area were 29.774, 18.579, 14.416, 11.186, 8.679 and 6.734 mm, respectively. The red warning thresholds for the average rainfall intensity at 1, 3, 6, 12, 24 and 48 hours under different early rainfall conditions in low mountain terrain areas were 28.849, 15.542, 10.520, 7.121, 4.820 and 3.263 mm, respectively. [Conclusion] Under the condition of rainfall in the early 24 hours period, the sensitivity of low mountainous areas to rainfall was significantly higher than the sensitivity of hilly areas. The critical warning thresholds at 1, 3, 6, 12 and 24 hours in low mountainous areas were significantly lower than those in hilly areas. However, with the further extension of rainfall duration, the critical warning thresholds at low mountainous areas and hilly areas tended to be similar.