Climatic types of water balances in the tropics

Abstract

One of the most important climate criteria of the tropics is the absence of thermic seasons. Thus, hygric seasons become more relevant for ecosystem functioning and are of special importance for plant growth. Within this chapter different climate types of the tropics are discussed on the basis of their annual water budget. The humid climate type appears across the rain equator within or close to the ITCZ. It is distinguished by a clear water surplus and all months show a positive water balance in the long-term mean. The semi-humid climate type prevails at a certain distance from the Equator and the ITCZ. It is characterized by a distinct rainfall seasonality and the occurrence of more than 3 -4 arid months. In terms of the arid climate type the arid period is in general longer than the humid period and precipitation amounts decrease almost towards zero within the desert areas.