引黄灌区水沙资源配置技术的研究

Study on main techniques of water and sediment resources allocation in irrigation system of the Lower Yellow River

引黄灌区水沙资源配置关键技术包括灌区减沙沉沙技术、引水分沙技术、渠道输水输沙技术等。通过引黄灌区引沙和沉沙资料的分析,总结了灌区减沙技术和有害泥沙拦沉技术,减沙主要是通过控制引水含沙量或减少引水量来实现,有害泥沙的拦沉主要是利用渠道拦沙设施和沉沙池拦截和沉积有害的粗颗粒泥沙。结合渠道输水输沙能力,分析了提高灌渠输沙能力的工程措施和非工程措施,工程措施包括加大渠道比降、渠道衬砌、改造阻水建筑物、优化断面等,非工程措施主要是指水沙调控技术。通过分析渠道引水分沙特征,进一步探讨了引黄灌区自流灌溉和提水灌溉的特点,指出自流灌溉的支渠引水含沙量略低于或等于干渠含水量;若提水泵站进口合理布置在平均含沙量水深以下,将会有利于渠道减淤。

The main techniques of water and sediment resources allocation in irrigation system of the Lower Yellow River were summarized, which includes the sediment reduction and sediment sinking technique, water and sediment transport technique, water and sediment diversion teehniqueetc. The sediment reduction and harmful sediment control are stated based on the harmful sediment concept in the irrigation system, of which the former will be realized on controlling diversion sediment concentration or water diversion reduction, and the latter will become true based on the harmful sediment interception and settlement. The structural and non-structural measures for enhancing the sediment transport capacity of the canal are summed through analysis, of which the former includes the slope increase, canal liner, improvement of the flow block bridges and optical cross-section, and the latter consists mainly of water and sediment controlling techniques. The water and sediment diversion characteristics of the gravity irrigation and pumping irrigation were analyzed in theory. When the diversion sediment concentration by gravity in branch canal is less than that in trunk canal, the trunk canal will be in status of deposition increase. When the pumping station and its inlet are arranged suitably, it is good at deposition decrease in the trunk canal.