Future groundwater extraction scenarios based on COMSOL multiphysics for the confined aquifer at Linfen basin, Shanxi Province, China

Figures & data

Table 1. Phreatic aquifer drawdown data of seven major basins in Shanxi Province in year 1991–2005

Year (a)	Drawdown value of each basin (m)
	Tianyang	Datong	Yiding	Taiyuan	Linfen	Yuncheng	Changzhi	Average
Accumulating value since 1991 to 2005	0.83	1.38	2.74	6.95	2.92	3.39	−1.85	2.72
Average value per Year	0.06	0.09	0.18	0.46	0.19	0.23	−0.12	0.18

Figure 1. conceptual model of boundary conditions of Linfen basin.

Figure 2. Hydraulic conductivity and location of the pumping well at Linfen basin.

Table 2. Recharge & discharge data per year of Linfen basin

Confined aquifer
Recharge (10^8 m^3/a)		Discharge (10^8 m^3/a)
Lateral recharge	1.43	Lateral discharge to the Yellow River (constant hydraulic head of 380 m)	\
Leakage recharge	1.32	Extraction	3.39

Figure 3. Hydraulic head surface maps in 10 and 20 years.

Table 3. Lateral discharge value to the Yellow River in years

Year (a)	Velocity integration^^ (m^2/s)	Lateral discharge* (m^3/s)	Lateral discharge (10^8 m^3/a)
0	\	\	\
2	0.0437	8.74	2.76
4	0.0254	5.08	1.60
6	0.0178	3.56	1.12
8	0.0123	2.46	0.78
10	0.0089	1.78	0.56
12	0.0067	1.34	0.42
14	0.0052	1.04	0.33
16	0.0044	0.88	0.28
18	0.0041	0.82	0.26
20	0.004	0.8	0.25

^{^} Velocity integration along specific head boundary.

* (Velocity integration) × (Aquifer depth 200 m).

Figure 4. Lateral discharge change curve to the Yellow River in years.

Table 4. Drawdown velocity of the well in years

Year (a)	2-Year cumulative drawdown of the well^^ (m)	Drawdown Velocity of the Well* (m/a)
0	\	\
2	175.1332	87.5666
4	35.2957	17.6479
6	23.7894	11.8947
8	17.7526	8.8763
10	14.1355	7.0678
12	12.0953	6.0477
14	10.6199	5.3099
16	9.0877	4.5439
18	7.7752	3.8876
20	6.8771	3.4386

^{^} 2-Year cumulative drawdown is calculated based on the hydraulic head difference of the well in the nearly 2 years.

* Drawdown Velocity means ^2-Year Cumulative Drawdown of the Well/2.

Figure 5. Drawdown velocity change curve of the well in years.

Table 5a. Groundwater extraction scenarios in 10 years

Confined aquifer prediction in 10 years
Recharge (10^8 m^3/a)		Discharge (10^8 m^3/a)
Lateral recharge	1.43	Lateral discharge to Yellow River (constant hydraulic head of 380 m)	0.56
Leakage recharge	1.32	Extraction	3.39
Drawdown velocity of pumping well (m/a)		7.07

Notes: Groundwater drawdown values in 10 years and their consequent impacts on confined aquifer lateral discharge amount to the Yellow River were predicted and depicted through Table 5a, which provide data of valuable reference for local groundwater management.

Table 5b. Groundwater extraction scenarios in 20 years

Confined aquifer prediction in 20 years
Recharge (10^8 m^3/a)		Discharge (10^8 m^3/a)
Lateral recharge	1.43	Lateral discharge to Yellow River (constant hydraulic head of 380 m)	0.25
Leakage recharge	1.32	Extraction	3.39
Drawdown velocity of pumping well (m/a)		3.44

Notes: Groundwater drawdown values in 20 years and their consequent impacts on confined aquifer lateral discharge amount to the Yellow River were predicted and depicted through Table 5b, which provide data of valuable reference for local groundwater management.

Figure 6. Drawdown velocity change curve of the well in years within 20% of current extraction amount – 0.66 × 10⁸ m³/a.