四川丹巴县泥石流灾害及其降雨预报阈值确定

Debris Flow Disaster Research and Threshold Determination of Precipitation Forecast in Danba County

  • 摘要: 利用2000~2020年丹巴泥石流和降雨资料,对丹巴泥石流灾害进行了研究。结果表明:丹巴县境内东北部的小金河谷是泥石流的高易发区,西北部的金川河谷是次易发区;5~9月均有泥石流发生,相对集中在6~7月,高发期为7月;短时强降水的雨强越大,发生灾害的风险越大,强降水出现频率最高的时段也是泥石流高发时段,19:00~05:00是泥石流灾害发生的高发时段;当降雨强度10~15 mm/h或15~25 mm/3h时,有一定泥石流灾害气象风险,为四级;降水强度在16~20 mm/h或26~35 mm/3h时,泥石流灾害气象风险较高,为三级;降水强度21~35 mm/h或36~60 mm/3h时,泥石流灾害气象风险高,为二级;降水强度≥35 mm/h或≥60 mm/3h时,泥石流灾害气象风险极高,为一级。前期有效雨量累积时间越长、雨量越大,出现泥石流灾害的可能性越大。

     

    Abstract: By using the data of debris flow and precipitation in Danba from 2000 to 2020, the debris flow disaster in Danba is studied. The results show that: The Xiaojin River Valley in the northeast of Danba County is a high-prone area of debris flow, and the Jinchuan River Valley in the northwest is a sub-prone area. Debris flow occurs from May to September, relatively concentrates in June to July, and the high incidence period is July. The greater the intensity of short-term precipitation, the greater the risk of disasters, and the period with the highest frequency of heavy precipitation is also the peak period of debris flow, with the period from 19 : 00 to 05 : 00 being the period of high incidence of debris flow disasters. When the precipitation intensity is 10~15 mm / h or 15~25 mm / 3h, there is a certain meteorological risk of debris flow disaster, which is level 4. When the precipitation intensity is 16~ 20 mm /h or 26~35 mm /3h, the disaster risk is the third level. When the precipitation intensity is 21~35 mm /h or 36~60 mm /3h, the disaster risk is high, which is grade 2. When the precipitation intensity ≥ 35 mm / h or ≥ 60 mm / 3h, the disaster risk is extremely high, which is the first level. The longer the effective precipitation accumulation time and the heavier the precipitation are, the greater the possibility of debris flow disaster will be.

     

/

返回文章
返回