泽错公路夏果沟泥石流成因及防治

泽错公路是西藏自治区主骨架公路网络“六大通道”之一，由于该区域独特而又脆弱的自然环境因素，泥石流灾害分布广泛，暴发频繁，活动强烈，类型众多，严重地影响公路的畅通。泽错公路全长217km，有泥石流沟71条，平均密度为3．27条／10km，其中，夏果沟泥石流危害比较严重，其发育特征及其危害方式在公路沿线非常典型。夏果沟是一条高频率亚粘性泥石流沟，每年平均暴发泥石流10次左右，泥石流体含有大量石块，比较粘稠，汇集到公路后发生强烈堆积成灾，形成路堑阻断交通。每次泥石流暴发其堆积厚度可达2m以上，长度65m左右，一般要2—3d或更长时间才能清除，严重地影响到公路畅通。根据夏果沟泥石流对该段公路及灌渠和农田的危害特点，防治工程的重点是将泥石流固体物质拦蓄在沟内，采取拦挡停淤的工程整治措施。工程实施后，该公路段泥石流灾害消除，保证公路畅通和灌渠及农田的安全，取得良好的效益。

Prevention of Debris Flow of Xiaguo Gully along the Zecuo Highway

The Zecuo highway is one of six key lines in Tibet, which has constantly suffered from frequent disasters of debris flow of various kinds due to fragility of environment. The highway is 217 km long with 71 gullies of debris flow distributed along, in number density of 0.327/km. Among these gullies the most severe is Xiaguo, of which debris flow is of high frequency and subviseosity. Each year witnesses some 10 debris flows blocking or interrupting the traffic. Deposition may reaches up to 2 m and more in depth and 65 m in length. Considering its harm to the road and farmland, engineering works are designed to trap sediment and boulders, bringing about security of traffic and farmland.