Local factors important for water availability
An important issue that has grabbed the attention of scientists and policy makers alike is the amount of freshwater that will be available to populations across different climate settings, especially as rain belts reorganize in response to warming temperatures over the 21st century. The amount of freshwater available on land, calculated from runoff, is a function of supply and demand, where annual rainfall determines the supply and the dryness determined by solar radiation largely controls the demand. Local factors, such as vegetation and soil types that are directly tied to regional climate, modulate the surface water supply and demand. However, there are no observations to quantify the effect of regional climate on surface water availability.