Human impacts on hydrological cycle

• Deforestation causes less vegetation that is able to intercept water, hence less evaporation
• Fewer trees mean less water is returned to the atmosphere by transpiration
• Agriculture means soils are compacted by heavy machines and livestock this means no water can infiltrate the soil this increases the surface runoff
• Rapid surface runoff can create flooding
• Urban development creates more impermeable surfaces where surface runoff can occur
• Global increase in temperatures effects rates of evaporation, transpiration and precipitation among other rates
• Water abstraction refers to process of taking or extracting water from natural resources for various human uses
• Water abstraction reduces volume of water in surface stores
• Water abstraction increases during dry seasons
• Human abstraction from aquifers as an output to meet water demand is larger that the input of water, this leads to goobal decline of water in stores
• Water abstraction can be bad if water sources are not returned, it affects downstream flow
• Rivers of Tibet, provide water to 1500 million people, growing demand has led to conflict and shortages in some areas