Human impacts on water systems

Irrigation

The watering of plants through artificial means

Types of irrigation

• Surface irrigation: water is applied directly through soil through canals and ditches 

• Drip irrigation: delivered to roots of plants (no evaporation / run-off

• Sprinkler: sprayed

Fertiliser

Substances mainly composed of nitrates, phosphorus, and potassium, added to increase soil fertility.

Eutrophication

The natural or artificial enrichment of a body of water, particularly due to nitrates and phosphates

Algae

Aquatic organisms that perform photosynthesis to produce their own food

manure

An organic fertiliser made from the faeces and urine of animals.

Machine use

Heavy machinery such as tractors can compact the soil. Compact soil is less permeable, so water is not absorbed effectively by the soil. This resulting increased surface run-off contributes to more frequent and severe flash floods

Deforestation

Cutting of trees to provide timber or land for human activities.

Deforestation (flooding)

When forests are cleared, the network of tree roots no longer absorbs rainwater. Thus, rainwater flows rapidly over the soil's surface, increasing the surface run-off. During heavy rainfall events this poses a risk of flooding , as the water collects quickly and overflows into nearby water bodies. It also means that less water reaches groundwater storages.

afforestation

Planting large numbers of trees on land which has few or no trees.

urbanization

The process of making a landscape more built-up, industrialised and dominated by close human settlements.

direct ways to measure water quality

Measure actual physical, chemical, or biological properties of water.

Indirect ways to measure water quality

Assess factors that influence water quality, not water itself.