应用人工阶梯 深潭系统治理泥石流沟的尝试

泥石流的主要破坏性在于其能量巨大，输送大量物质造成生命财产损失，消耗泥石流的起动及运动能量能防止泥石流发生或使泥石流的破坏性大大降低，为泥石流治理提供了新的思路。通过在甘肃西汉水流域的泥石流支沟拦山沟进行人工阶梯 深潭系统试验，2009~2010年汛期观测发现阶梯 深潭系统能增强沟道阻力，抬高侵蚀基准面，从而控制侵蚀下切，且多级的阶梯 深潭系统通过跌水和水跃能有效消散水流能量，在一定程度上抑制了泥石流的起动和加速，使得泥石流在阶梯上游停留堆积，淤满的阶梯在河床纵剖面仍能保持阶梯形态，起到增强阻力消能的作用，减小了拦山沟泥石流对下游的破坏。消能结构对大坡度山区河流起重要作用，不论是人工消能结构还是自然消能结构，都能起到增阻消能的作用，对山区河流治理起到积极的作用

FIELD EXPERIMENT FOR DEBRIS FLOW CONTROL BY USING ARTIFICIAL STEP-POOL SYSTEM

Debris flow,which commonly contains high kinetic energy,has terrible damage capacity to cause heavy disaster by its strong impact force and transporting huge volume materials.If the kinetic energy of debris flow could be completely or partly dissipated before its initiation or deposition,the disaster caused by debris flow may be avoided or be mitigated to minimization.Step-pool systems have the maximum flow resistance and stability condition,which potentially could be used for mountain streams training and ecological restoration.In this paper,17 artificial step-pool systems were built on Lanshan Gully,a tributary of Xihanshui River in Gansu Province in Northwest of China.The experimental study of step-pool systems started from June 2009.Based on observation during two flood seasons of 2009-2010,the artificial step-pool systems raised the base level by deposition.And the riverbed and bank was protected from erosion.Thus,the bed and bank slope were stabilized.Moreover,the kinetic energy of debris flow was dissipated by hydraulic drop and hydraulic jump of the step-pool systems,and sediment deposited on the upstream of steps.Finally,there was little debris flow occurred in Lanshan Gully from 2009 to 2010.The results show that energy dissipation structures are the key to stabilize high gradient mountain streams.The resistance structures,such as step-pool systems,whether developed by nature or by man-made could dissipate the flow energy and keep the kinetic energy of the flow below a critical energy for initiation of debris flows.