hydrological cycle

The natural hydrological cycle is in a state of?

• dynamic equilibrium 

Abstractive uses of water

• domestics

• agricultural

• industrial

Non abstractive uses of water

• Wildlife conservation

• Recreational

• Transport

• Energy production

Human Impact on the Hydrological Cycle

• deforestation

• agriculture

• urban development

• global climate change

how does deforestation impact the H2O cycle

• Vegetation changes where precipitation hits the ground

• trees intercept precipitation

• returns soil water to the atmosphere via transpiration

how does agriculture affect the H2O cycle

• Soil compaction increases runoff

• crop irrigation increases evaporation rates

• loss of soil biota reduces infiltration and reduces water retention

how does urban development affect the H2O cycle

Increase impermeable surfaces, which can lead to flooding

water quality criterias

• physical

• chemical

• biological

the physical criteria for water quality

Turbidity - a measure of how turbid or cloudy water is. Water with a high level of suspended sediment is known as turbid.

the chemical criteria for water quality

Various chemical techniques can be used to test for different chemicals. e.g. pH, pesticide and heavy metal concentrations

the biological criteria for water quality

The detection of pathogens in the water, e.g. the presence of E. Coli