Study On The Water-salt Balance And Sediment-water Control For A Irrigation Region In The Lower Yellow River

The irrigation areas in the lower reaches of the Yellow River distribute mainly in the under Qin River and the area along banks in the Shandong province and Henan province. The irrigation area is the important economic development belt and the grain, cotton and oil producing area in our country. And the developing history of agricultural irrigation is long. The water yield for the Yellow River is 12 billion cubic meters annually and it accounts for 20.69 of the flow of annual gross of the Yellow River. But the structure of development and utilization of water resources is unreasonable, the irrigation mode is extensive and the irrigation technique is uncultured in the irrigation area. So these cause water ecology and environment of downstream irrigated area are worsen, the silt threaten are strengthen, soil desertification and soil erosion are aggravated, the production capacity of the soil drops, soil potential secondary Stalinization increases. Those influence the sustaining, stabile development of the agricultural and national economy of the low reaches guide yellow irrigated area.The actuality of the development and utilization of water resources of the irrigated area in the low reaches of the Yellow River, the actuality of the environments and changes and the silt deposit, and the deposit law and cause have been discussed in the paper. The questions of the development and utilization of water resources have been analyzed dealt in the paper. The main reasons of the exacerbation of the water ecology and environment and the influence of the soil salinization in the irrigation area have been opened out. The model of the disposing and managing with net benefits being most and the balanced equation of water and salt has been set up. The regulate technology of the water and sediment has been proposed. And the technology of dealing with and utilizing the sediment and the project of inducing the silt has been studied.The WeiShan irrigated area is taken as an example in the paper. Based on the analyses of the amount and characteristic of the water resources in the secondary irrigated area, utilizing the model of the disposing and managing, the distribution of the groundwater and the water of Yellow River in the different period within the year has been studied and the optimum cultivated area and output of the wheat and maize have been analyzed. According to the precipitation and the serial materials of irrigated area in the Yellow River and the balanced equation in water and salt, the change of water and salt reserves of irrigated area has been researched, the intensity of salinization of soil of the irrigated area has been predicted, the measure which controls the process of salinization of soil has been proposed. The actuality of the sediment deposition in the WeiShan irrigated area has also been analyzed, the trend of the sediment deposition has been predicted, and the regulate technology of the water and sediment has been studied.The paper has the stronger directive significance in the reasonable development and utilizing the water resource, improving the irrigated area environment, avoiding the secondary salinization of soil and promoting the sustainable development of irrigated area in the lower reaches of the Yellow River.