ENSO与云南蒋家沟泥石流灾害发生的关系

通过分析近40年来出现的ENSO事件对云南东川蒋家沟泥石流活动的影响可知,El Ni(~n)o与LaNi(~n)a对其的影响正好相反,且El Ni(~n)o的影响大于La Ni(~n)a的影响.El Ni(~n)o年,泥石流年发生频次、径流量和输沙量偏少的概率均较大,泥石流活动减弱的倾向明显;La Ni(~n)a年,虽有一定的对应关系,但不如El Ni(~n)o年明显,且影响更复杂一些,总的来说,泥石流年发生频次、径流量和输沙量偏多或持平的概率较大.

Relationship between ENSO and occurrence of debris flow disaster in Jiangjia Ravine, Yunnan

Using the observation data gotten from Dongchuan Debris Flow Observation and Research Station since 1965, the primary study on debris flow relative to ENSO event in Jiangjia Ravine is made, and the following conclusions are drawn. ENSO event is one of the factors affecting the activity of debris flow in Dongchuan. The impact of E1 Nino event on the debris flow in Jiangjia Ravine is more serious than that of La Nina event during the recent 40 years. Generally, the E1 Nino event may decrease the precipitation in summer season. The probability of low qrequency, low runoff and low sediment transformation of debris flow is greater. On the contrary, the La Nina event may increase the precipitation in summer season, and the impact of the event is much complicated and not so obvious. Then ,the high frequency, high runoff, high sediment transformation and normality of debris flow are predominant. The findings suggest that further research into the relationship between ENSO event and the activity of debris flow in Dongchuan would be worthwhile.