Study : Human activity is disrupting the freshwater cycle in parts of the world

An international team of hydrologists and climatologists has comprehensively studied the freshwater cycle on Earth and concluded that human activity has violated this cycle in 18 percent of the world's regions.

The media office of Aalto University in Finland indicates that the scientific team has reached the conclusion that the movement of fresh water between rivers, ponds, lakes, other bodies of water and other environments has been greatly violated as a result of human activity, and these violations are concentrated in the tropical regions of South America and Africa, and in the central regions of The United States and Mexico, in southern Europe and China, in India and the Middle East.

“Our analysis showed that strong deviations in the pattern of water movement through reservoirs and soil began mostly in the past century and a half and in a greater number of regions than in the pre-industrial era,” says Willi Virke, a scientific researcher at the university. “This indicates that humanity is violating the natural freshwater cycle.” In the world".

The researchers reached this conclusion from a comprehensive analysis of how the pattern of freshwater movement through soil and reservoirs changed in all regions of the world between the middle of the seventeenth century and the beginning of this century. This time period covers both the pre-industrial era (1661-1861) and the modern era (1861-2005), during which the appearance of many areas of the Earth changed radically, including as a result of the construction of electrical power plants. Dams and other hydraulic installations.

The researchers studied the impact of these changes on the water cycle on Earth by using a detailed model of the Earth's hydrosphere to calculate how the movement of fresh water flow in soil and reservoirs changes with very high spatial resolution. For this purpose, they divided all the lands into squares with an area of ​​50 x 50 km, and monitored the extent of change in the level of soil moisture, the volume of water flowing through rivers, lakes and other bodies of water, in addition to other hydrological indicators.

It became clear to them that hydrological anomalies, including droughts, floods, and other deviations from the typical amount of moisture in the soil or reservoirs, covered approximately 9.4-9.8 percent of the total land area on a monthly and annual basis in the pre-industrial era. But this number doubled over the next century and a half and now covers about 18 percent of water bodies and 15 percent of soil. Scientists link this to human economic activity.