Evaluation Of The Allowable Yield Of Corridor In The Downstream Valley Of Tuwei River

Tuwei River is well-known as an energy and chemical base in northern Shaanxi. And itis the water supply source of Jinjie, the Great Barrier Industrial Park and Shenmu City. Inrecent years, with the rapid development of the energy resources and chemical industry in theriver basin, the runoff of downstream has sharp declined and the contradiction between watersupply and demand has become increasingly prominent. Therefore, it’s particularly urgent tocarry out the allowable yield evaluation of groundwater resources in Tuwei River Valley, anddesign proper water intake engineering and hydraulic project which can provide a guaranteedsupplying yield in the region.In this paper, the proposed corridors are adopted for water intaking in the study area onthe basis of full understanding of the natural geography, geology and hydrological geology ofthe region combined with the construction and operating costs of the water intake structure.Firstly, make analysis of the runoff of the study area in order to calculate the inflow ofentrance section under different guaranteed rate. Secondly, make groundwater’s allowableyield evaluation by setting up three-dimensional finite difference numerical model of region’smultiple corridors which run at the same time on the basis of coupled seepage-pipe flowtheory. We should calculate the allowable yield under the present situation and the conditionof a large quantity of water intaking respectively, so as to determine the proposed extractionof the corridors. However, due to the human exploitation of water resources, the remainingflow of the entrance section doesn’t continuously ensure the daily recommended extraction ofcorridors. So we suggest using the corridors with the reservoir in order to ensure the normalsupply of the corridors. The regulating reservoir which we design is an overyear regulatingreservoir with the diachronic method. It stores up the excess water in wet period of one yearto increase the supplying yield in water shortage period. Finally, we put forward protectionmeasures on the exploitation of the study area’s water resources.Nine proposed corridors are laid to exploit groundwater resources in the study area.Calculate the allowable yield respectively under the present situation and the condition of a large quantity of water intaking by setting up three-dimensional finite difference numericalmodel. The results show that:(1) the groundwater’s allowable yield is103100m3/d in thenormal season(50%guaranteed rate);(2) the groundwater’s allowable yield is85100m3/d indry season(90%guaranteed rate);(3) the groundwater’s allowable yield is46000m3/d undersafflower drainage of agricultural irrigation water in dry season(90%guaranteed rate);(4)under safflower drainage of agricultural irrigation water and the water intaking in upstream ofTuwei River, the groundwater’s allowable yield is21000m3/d with a small size regulatingreservoir for groundwater regulating whose utilizable capacity is227×104m3. Throughdemonstrating on guarantee degree, the groundwater’s allowable yield has rechargeassurance.