Hydrospheric interaction

The global water budget

Although water is found everywhere on earth, its distribution of highly unequal. The hydrosphere refers to all the water on the Earth which may be present as ocean water, runoff, snow, ice, groundwater or as water vapour in the atmosphere. The vast majority of water is found in the seas and oceans and is undrinkable for humans.

Water is distributed and redistributed around the globe through the processes of the water cycle.

Local variations in the hydrosphere

The availability of water results from variation in the hydrosphere. These variations may arise from the local weather and climate, river systems or local groundwater sources.

Human impacts on the hydrosphere

Humans have altered the hydrosphere to suit their own needs for millennia, in fact it is not surprising that the first civilisations arose along the banks of major river systems such as the Nile, the Yangtze or the Euphrates. However, the scale and complexity with which humans are able to alter the water cycle is now much greater.

Humans can impact the hydrosphere in the following ways:

Alteration of river and run-off velocity and path.
Inputs of nutrient and heat pollution
excessive removal of water from either rivers or aquifers

The creation of dams and reservoirs
Changes to water chemistry
Removal of local flora and fauna

The Hydrosphere

The global water budget

Local variations in the hydrosphere

Human impacts on the hydrosphere

Further Reading