Physical geog

• The global water budget is comprise of stores such as: the oceans-97% of global water. 2.5% of stores are freshwater of which 69% is glaciers, ice caps, and ice sheets and 30% is groundwater. Surface and other freshwater only accounts for 1% of global stores- permafrost, lakes, swamps, marshes, rivers, living organisms
• 85% of solar radiation is reflected in polar regions
• Dense vegetation consumes 75% of precipitation in tropical rainforests
• In China, groundwater irrigates 40% of farmland whilst 70% of drinking water comes from groundwater
• meteorologicall drought is rainfall deficit with low precipitation, high temperatures, strong winds, increased solar radiation and reduced snow cover
• Hydrological drought is stream flow deficit- reduced infiltration, low soil moisture, little percolation and groundwater recharge
• Agricultural drought is soil moisture deficit- low evapotranspiration, reduced biomass and a fall in groundwater level
• Socio-economic drought is food deficit- loss of vegetation, increased risk of wildfires, soil erosion and desertification
• climate change will reduce inputs, reduce stores but may increase outputs with the hydrological cycle
• 66% of the world's population live in areas that have access to only 25% of the world's annual rainfall