In an article published on Thursday 16 January, the European Commission argues that global urbanisation has led to a deterioration in water quality over the last twenty years, having analysed more than 20,000 independent research publications dating from 1976 to 2022.
The European Commission concluded that urbanisation is the landscape change “most responsible for water-quality deterioration”. To reach this conclusion, the researchers examined the link between changes in landscape indicators and water quality. Five types of landscape composition showed “significant impact on water quality”: urban lands, agricultural lands, forests, wetlands and grasslands.
Urbanisation has led to an increase in “levels of total dissolved solids and metal ions” and a reduction in “dissolved oxygen in the water”. Farmland, meanwhile, causes “nutrient pollution by nitrogen and phosphorus from fertiliser run-off”, while ploughing and irrigation contribute to “increased solids in the water”.
As forest cover has a restorative effect on water quality, the researchers felt that increasing it could be beneficial, particularly at low latitudes closer to the Equator. According to the study, this solution could be deployed as part of a land-use change management strategy. (Original version in French by Florent Servia)