In general terms, the climate of a local or region is said to be arid when it's characterized by a severe lack of available water, to the extent of hindering or even preventing the growth and development of plant and animal life. As a result, environments subject to arid climates tend to lack vegetation and are called xeric or desertic. Juba, South Sudan is an Arid land. Concepts The expression 'available water' refers to water in the soil in excess to the wilting point. The air over a hot de… (More on Arid)