La deforestación tiene un efecto sorprendente en la calidad del agua, dice nueva investigación
Tiene implicaciones devastadoras para el acceso al agua.
Researchers in Malawi have made a groundbreaking discovery about the relation between clearcutting forests and clean water.
While it has long been thought that deforestation helps — or at least does not hurt — access to water in nearby communities, two scientists have published what they believe is the first paper proving that wrong.
“[People believe] that deforestation will not have a negative effect on water access to people," Hisahiro Naito, an economist and associate professor at Japan's University of Tsukuba, writes in an email to Pacific Standard. "We have challenged this view."
While deforestation may make more water available (called “water yield”), that doesn’t mean that it’s safe to drink. The forest floor acts as a sponge for runoff sediments, helping water treatment systems — which are rare in many areas in Malawi.
Naito and co-researcher Annie Mwayi Mapulanga examined satellite data from the Ministry of Natural Resources, Energy, and Mining over a 10-year period beginning in 2000. They then compared this data to safe water health surveys taken over the same period. The results of their research were published in March in the Proceedings of the National Academy of Sciences.
Over the course of their research, Malawi’s forest cover shrank by more than 14%, Pacific Standard reports, making it one of the highest rates of deforestation in Africa. Forests have been cleared largely for fuelwood and farms, leading to 9% less clean drinking water for Malawians.
"At first, [a] 9-percent decrease looks small," Naito writes, adding that that such a substantial decline actually reduces citizens’ reliable access to clean water by 5%.
The trend of deforestation in Malawi is nothing new. Over the past three decades, the effect of deforestation is equivalent to 18% less rainfall, Naito writes. This is only expected to grow with the effect of climate change.
Some 17% of Malawians drink water from unsafe sources, shows 2010 data, as reported by Pacific Standard.
The good news: Slowing down deforestation, and planting more trees, may reverse the effects, and better help the southeastern African nation protect itself against climate change.
"Our study shows that, if there is more forest in Malawi, Malawi can [resist] those events," Naito writes, "and people can still have access to clean water."