A study by a research team in the United States and other countries has revealed that groundwater, which is used for a variety of purposes, is on the decline around the world.
The research team believes that in dry regions, pumping up large amounts of groundwater for agricultural purposes may have an effect, and that urgent measures are needed.
This was published by a research team in the United States and elsewhere in the scientific journal Nature on the 24th.
The research team analyzed approximately 170,000 wells in more than 40 countries around the world, and compiled changes in groundwater levels at 1,693 locations.
According to the results, since the beginning of this century, groundwater levels have decreased by more than 10 cm per year in approximately 36% of the total, and in approximately 12% of the total, they have decreased significantly by more than 50 cm per year. It turns out that there is.
The decline in water levels is particularly noticeable in areas where agriculture is practiced in dry climates, and the research team believes that this may be due to the pumping of large amounts of groundwater used for agriculture. Masu.
On the other hand, there are approximately 6% of areas where the water level has recovered by more than 10 centimeters per year, and an investigation of these areas reveals that there were also areas where policies such as restricting the pumping of groundwater were taken. is.
When groundwater decreases to an extreme level, it may become impossible to use it as before, so the research team says that effective measures should be taken immediately in areas where groundwater is decreasing.