WORLD HISTORY

Detailed explanation-1: -A hot-dry climate is generally defined as a region that receives less than 20 in. (50 cm) of annual precipitation and where the monthly average outdoor temperature remains above 45°F (7°C) throughout the year.

Detailed explanation-2: -Arid regions are those where the rainfall is very low, and consequently little surface moisture may exist. Major arid regions can be found around the world in North America, South America, Africa, Asia and Australia, and are commonly also referred to as deserts.

Detailed explanation-3: -Regions lying within the dry climate group occur where precipitation is low. There are two dry climate types: arid and semiarid. Most arid climates receive 10 to 30 centimeters (four to 12 inches) of rain each year, and semiarid climates receive enough to support extensive grasslands.

Detailed explanation-4: -In C. W. Thornthwaite’s 1948 climatic classification, any climate type in which the seasonal water surplus does not counteract seasonal water deficiency; thus it has a moisture index of less than zero. These types include the dry subhumid, semiarid, and arid climates.