CoachGroundwater is the water under the ground that fills the pores and cracks of the soil and of the rocks.
示例
Example 17.12 (A new fuel tank for the farm)
A farmer on a chalk hillside drinks the water of her own well, halfway up the slope, and wants to put a new fuel tank in one of two fields: one uphill of the well, one downhill of it, near the stream. The groundwater flows downhill. A leak from the field uphill would drift down towards the well; a leak from the field downhill would drift away from it, towards the stream. The field downhill of the well is the better choice for the well — and a tank on a tray that holds any leak is better still, since the stream matters too.