低频泥石流特征及防治——以四川汶川县茶园沟为例

The characteristics and control of the low frequency debris flow——Taking the Chayuan gully debris flow Wenchuan County, Sichuan Province as a example

低频泥石流指30a以上发生1次的泥石流。尽管发生频率很低,但由于自身的特征及人们认识上的原因,其造成的人员伤亡和财产损失却居各类泥石流之首。对低频泥石流的研究在预防和减轻泥石流灾害方面有着重要意义。文章以2003年8月9日发生在四川汶川县茶园沟的泥石流为例,采用形态调查法和称重法等方法确定了流量、流速及重度。分析了其物质来源及形成的自然和人为原因,探讨了低频泥石流的特征。针对低频泥石流的低频性、破坏性和隐蔽性特点,同时考虑到低频泥石流沟的防治受保护对象的重要程度及资金投入等因素的限制,提出了进行泥石流危险性分区、搞好小流域水土保持、普及泥石流防灾减灾知识及加强监测和预警预报等措施,这对减轻低频泥石流区的灾害有一定的借鉴意义。

The low frequency debris flow refers to the debris flow which occurs once for more than thirty years. Because of the low frequency and short of people＇ s cognition, it always causes huge harmness comparing with other debris flows. Taking the Chayuan gully debris flow, Wenchuan County, Sichuan Province occurring on August 9,2003 as an example, this paper discussed the characteristic of the low frequency debris flow from the material source and the reason caused by human being and nature. At the same time, the velocity, the discharge and the density were calculated by the way of configuration investigation and weighing density. Aiming at the characteristic of the low frequency, the large disaster and the concealment, considering the needed fund and the importance of the protected object, some measures of precaution and control were set up such as division of risk analysis of debris flow, reservation of water and soil of small watershed, popularization the knowledge of averting disaster and strengthening surveillance and prediction, Which could provide the use of reference for the harness of the low frequency debris flow area.