The total amount of rain falling on land surfaces across the globe remains relatively constant in each decade. The distribution of rainfall is patchy and dry desert areas are clearly visible. On a global scale the size of very dry or very wet areas changes only slightly. However it is predicted that the intensity of rainfall events will increase leading to more water running off the land and less being retained in the soil.
The rainfall maps were generated by the Centre for Ecology and Hydrology CEH using Arc GIS software, and use CRU TS2.1 data (CRU= Climate Research Unit). The decadally averaged annual total precipitation (mm) represents the amount of precipitation in one year, averaged over the decade.