四川省山区城镇山洪灾害特征分析

Analysis of characters of torrent disasters in the towns of the mountain areas,Sichuan,China

四川省山区城镇山洪灾害分为溪河洪水、泥石流、溪河洪水+泥石流与溪河洪水+泥石流+滑坡四种类型。通过对近50年四川省受山洪灾害危害的典型山区城镇进行调查,从灾害的爆发频率、威胁人口、死亡人口及财产损失四个方面进行相关性分析得出:总体上山洪灾害爆发频率越低,造成的威胁区内人员死亡概率和人均财产损失越大。各类山洪灾害的特征不同:溪河洪水爆发频率高,造成人员伤亡较小,财产损失较大;泥石流的爆发频率低,人员伤亡大,财产损失较大;泥石流+溪河洪水的综合灾害爆发频次低,人员伤亡和财产损失相对较大;泥石流+滑坡+溪河洪水的综合灾害爆发频次最低,威胁人口最多,造成人员伤亡和财产损失都很大。

There are four kinds of torrents in the towns of the mountain areas in Sichuan Province. They are pure floods, debris flows, flood ＋ debris flow, and flood q-debris flow ＋landslip. Based on the data on the latest 50 years, the authors research the torrent characters, and the result shows that： （1） the disasters of a pure flood are characterized by high frequency and low loss; （2） the disasters of a debris flow are low frequency and high loss; （3） the disasters of flood ＋ debris flow are low frequency and make casualty and economic loss more than the debris flow; （4） the disasters of flood ＋debris flow ＋landslip are the lowest frequency, largest scale and the casualty and economic loss are the most of all. On the analysis of relativity between the frequency and the loss, the authors find that the lower the frequency is, the more the loss be.