灌区水闸的闸下普遍存在着冲刷现象，以往对闸下冲刷的研究，无论采用原型观测或模型试验的方法，通常是在恒定流的水力条件下进行研究的。消能防冲设计时采用的公式，大多数也是由恒定流而得出的。实际上在闸门开启过程中，过闸水流为非恒定流，闸门开启的时段内闸下产生的冲坑深度，占一次放水过程产生冲坑深度的一半。因此在灌区水闸的消能防冲设计中应考虑非恒定流的水力条件 Flood irrigation gate under the gate there is widespread erosion phenomenon, the past under the gate scour study, regardless of the use of prototype observation or model test methods, usually under constant flow conditions of the hydraulic research. Energy-saving anti-shock design used in the formula, most are derived from the constant flow. In fact, during the process of opening the gate, the water flow across the gate is unsteady. The depth of the puddle generated under the gate during the gate opening period accounts for half of the depth of the puddle during a drain. Therefore, in the design of energy-dissipating and anti-scouring of sluice gate, hydraulic conditions of unsteady flow should be considered