The Trend scenario forecasts further deterioration of aquatic ecosystems and their services (Janse et al., 2015). The main causes of freshwater biodiversity loss under the Trend scenario are expansion of agricultural land and intensification of land use, fragmentation and infrastructure, climate change, water flow alteration, exploitation of natural ecosystems – including fisheries and forestry – and tourism. Various water users each have their own demands and effects on the quantity and quality of the water as well as on the shape (morphology, level of canalisation, disruptions) of both surface water bodies and groundwater (Table 1). Of these, agriculture has the highest consumption globally, using at present about two thirds of the water that is mobilised from surface and groundwater (Rockström et al., 2009). Its impacts are also highest (Table 1), on both terrestrial and aquatic ecosystems and their biodiversity.
Groups of water users with an indication of their specific water demands and selected impacts.
Users . | Relative requirements . | Impacts on . | |||
---|---|---|---|---|---|
Quantity . | Quality . | Quantity . | Quality . | Morphology . | |
Irrigation and livestock | High | Moderate | High | Moderate/high | High |
Domestic (drinking water) | Low | High | Low | Low | Low |
Cities (wastewater) | Low | Low | Low | High | Low |
Manufacturing | Moderate | Moderate | Low | High | Low |
Electricity | High | Low | Low | Low | High |
Transport/navigation | Moderate | Low | Moderate | Low | High |
Nature | Moderate/high | High | Low | Low | Low |
Flood protection | Moderate | Low | Moderate | Low | High |
Users . | Relative requirements . | Impacts on . | |||
---|---|---|---|---|---|
Quantity . | Quality . | Quantity . | Quality . | Morphology . | |
Irrigation and livestock | High | Moderate | High | Moderate/high | High |
Domestic (drinking water) | Low | High | Low | Low | Low |
Cities (wastewater) | Low | Low | Low | High | Low |
Manufacturing | Moderate | Moderate | Low | High | Low |
Electricity | High | Low | Low | Low | High |
Transport/navigation | Moderate | Low | Moderate | Low | High |
Nature | Moderate/high | High | Low | Low | Low |
Flood protection | Moderate | Low | Moderate | Low | High |