In which cases will make the shortage of water is certain or some season only. But if it rains less than the rate of evaporation of water, it will make the area caused a shortage of water that continued permanently.
In the latter case, it makes a water shortage or a certain season only. If rain is less than the rate of evaporation of water will cause the condition that caused water shortages contiguous permanently.
In the latter case which will make the water shortage in some range or some season only. But if it rains less than the rate of evaporation of water, it will make the state of water shortage is low, continuously permanently .