Question

Long periods of less rainfall usually causes the condition of___.

Answer 1

Long periods of less rainfall usually causes the condition of Draught.
Drought is caused by drier than normal conditions that can eventually lead to water supply problems. Really hot temperatures can make drought worse by causing moisture to evaporate from the soil.
When a particular area gets less rain than usual, the soil gets much less moisture, too. The soil starts drying out and plants die. When this pattern continues for several weeks, months, or years, the flow of streams and rivers decreases, and water levels in lakes, reservoirs, and wells fall. Eventually, the unusually dry weather causes water supply issues, and the dry period becomes a drought.