semiarid climate

A climate of low rainfall characterised by irregular and unpredictable rainy seasons. Semi-arid regions often form on the margins of deserts, or in rainshadow basins. They are more hazardous that deserts because, form time to time, there is enough rainfall to support farming, which encourages people to overdevelop them and leads to catastrophe when a long period without rain follows (know as when the rains "fail"). The Sahel of Africa is a region of semi-arid climate with a large population where disasters due to rain failures are common. The Great Plains region of North America is a semi-arid region. The disaster that produced the "Dust Bowl" was due to a period of rain shortage.