Aridification is the process of a region becoming increasingly arid, or dry. It refers to long term change, rather than seasonal variation.
It is often measured as the reduction of average soil moisture content. It can be caused by natural or anthropogenic means such as climate change, reduced precipitation, increased evaporation, lowering of water tables or changes in ground cover. Its major consequences include reduced agricultural production, soil degradation, ecosystem changes and decreased water catchment runoff.