The four existing water sources in Dongshan Coal Mine are Guanmengqian water source, Zaogou water source, mine water inrush water source and mine drainage water source. Mine drainage is normal except for bacteria exceeding the standard, and can be used as domestic water or industrial water with a little treatment. According to the calculation of optimal management of drainage and water supply, after 10 years, the four water sources can provide 65000m3/d, 75000m3/d, 6000m3/d and 4000m3/d respectively. The main water users in Dongshan are railway bureaus, power plants and coal mines, and the surplus water resources are supplied to Taiyuan City. The estimated water consumption of the above three departments 10 years later is: railway bureau 15000m3/d, power plant 5000m3/d, coal mine 5000m3/d, and the rest will be supplied to Taiyuan.

The water supply of Guanmengqian water source to railway bureau, power plant, coal mine and Taiyuan city is Q 1, Q2, Q3 and Q4 respectively, and the corresponding benefit coefficients are C 1, C2, C3 and C4. The water supply of Zaogou water source to railway bureau, power plant, coal mine and Taiyuan city is Q5, Q6, Q7 and Q8 respectively, and the corresponding benefit coefficients are C5, C6, C7 and C8. The water supply of water inrush points to railway bureau, power plant, coal mine and Taiyuan city are Q9, Q 10, Q1and Q 12 respectively, and the corresponding benefit coefficients are C9, C 10 and C12. The water supply of mine drainage to railway bureau, power plant, coal mine and Taiyuan city are Q 13, Q 14, Q 15 and Q 16 respectively, and the corresponding benefit coefficients are C 13, C 14 and C. Its objective function is the maximum benefit of water resources utilization, and the expression is as follows:

Optimal management of drainage, water supply and environmental protection in North China coalfield

Constraints include:

(1) The water supply of water source cannot exceed the maximum water supply of each water source, and there are four constraints:

Optimal management of drainage, water supply and environmental protection in North China coalfield

(2) The sum of water supplied to each user should not be less than the water consumption of each user. There are three constraints, in the absence of constraints, as much as possible to supply water to Taiyuan city.

Optimal management of drainage, water supply and environmental protection in North China coalfield

(3) The water quantity supplied by each water source to each user shall not exceed the water consumption of each user, with the constraint of 12, and Q4, Q8, Q 12 and Q 16 are the water quantity supplied to Taiyuan, with no upper limit constraint.

Optimal management of drainage, water supply and environmental protection in North China coalfield

(4) Non-negative constraints of each variable.

Optimal management of drainage, water supply and environmental protection in North China coalfield

To sum up, the mathematical model of optimal management of water resources allocation is:

Optimal management of drainage, water supply and environmental protection in North China coalfield

st Q 1+Q2+Q3+Q4≤65000m3/d

Optimal management of drainage, water supply and environmental protection in North China coalfield