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黄河上游沙漠宽谷段支流——十大孔兑的高含沙洪水多次淤堵黄河干流,造成灾害。基于实测水文泥沙资料和模型试验手段对孔兑高含沙洪水特点、淤堵干流过程和交汇区沙坝形态进行了研究。结果表明:孔兑洪水具有陡涨陡落、持续时间短、洪峰流量大、含沙量高、输沙量大等特点;孔兑洪水形成沙坝、淤堵黄河的过程可分为形成、相对稳定和冲刷3个阶段,支流洪水量级较大,形成的沙坝规模较大,沙坝冲刷历时也较长;孔兑高含沙水流入黄交汇区水流结构分区包括壅水区、回流区、高流速带、剪切层等组成要素,沙坝淤积形态模式包括壅水区、回流区、回流区下游淤积体和交汇区输水输沙窄槽;基于沙坝淤堵判别方法以及实测和试验数据提出了孔兑入黄交汇区沙坝判别条件。
Tributaries of the desert hilly valley in the upper reaches of the Yellow River - silt floods of the top ten holes repeatedly silt the Yellow River main stream, causing disasters. Based on the measured hydrological and sediment data and model test methods, the characteristics of flood-flood-sediment-flood, silting-up of main stream flow and the shape of sand bar in the intersection area were studied. The results show that the flood flood has characteristics of steep rise and fall, short duration, high peak flow, high sediment concentration and large amount of sediment transport. The formation of sand dams by flood floods can be divided into formation and relative Stability and scouring three stages, a larger flood flood tributaries, the formation of a larger scale of sand dam, sand dam erosion lasted longer; hole against the high concentration of sandy water into the Yellow River confluence of water flow structure partition, including water area, , High velocity belts and shear layers. The silt depositional patterns of silt dam include swill zone, recirculation zone, sediment body downstream of recirculation zone and narrow slot of water and sediment transport in the intersection area; The test data put forward the criteria for discriminating sand bars between the hole and the junction area of Yellow River.