Question

what happens to ground water reserves when ,a)rains heavily and b)does not rain at all

Answer 1

when it rains heavily the ground water increase and when it make the above land smooth and it results in land scapes
when it didnot rain at all the ground will be depleted

Answer 2

If it rains constantly over a span of time, it has the potential to restore terrain and surface water reservoirs. For example, if in a period of five hours, a district experiences over 150mm rainfall, it is contemplated substantial rainfall in a small period and may lead to runoff by increasing the water levels of the wells.

If it does not rain than groundwater deterioration is a sincere and problem in various places. When rainfall is less than average for various weeks, periods, or years, the flow of waters and rivers decreases, water levels in ponds and reserves decline, and the depth to water in wells progress. If dry weather continues and water-supply difficulties occur, the dry season can become a drought.