Question

quantifying fluxes to answer a question
an aquifer receives 40 m³ of precipitation and loses 10 m³ of water through natural movement.
how much water can be pumped from the aquifer to balance the budget?
○ 10 m³
○ 20 m³
○ 30 m³
○ 40 m³

Explanation:

Step1: Apply water - budget principle

The water - budget equation is \( \text{Inflow}-\text{Outflow}-\text{Extraction}=0\) (assuming steady - state, so change in storage \(\Delta S = 0\)). Let \(Q_{in}\) be the inflow (precipitation), \(Q_{out}\) be the natural outflow, and \(Q_{pump}\) be the pumped amount. Here, \(Q_{in}=40\space m^{3}\), \(Q_{out} = 10\space m^{3}\).

Step2: Solve for pumped amount

From \(Q_{in}-Q_{out}-Q_{pump}=0\), we can rearrange to \(Q_{pump}=Q_{in}-Q_{out}\). Substitute \(Q_{in} = 40\space m^{3}\) and \(Q_{out}=10\space m^{3}\) into the equation: \(Q_{pump}=40 - 10\).

Answer:

\(30\space m^{3}\)