Jakarta. Sumatra’s watersheds — ridges of land that separate waters flowing to different rivers and keep those waters pristine — have lost the largest amount of forest cover in the world over the course of 15 years, drastically reducing the quality of its water supply, World Research Institute's Global Forest Watch Water revealed on Tuesday (30/08).
More than 22 percent of Sumatra's forest cover, or 8 million hectares — an area almost as large as the entire province of North Sumatra — was destroyed from 2000 to 2014.
"Research shows that agricultural expansion, logging and infrastructure extension as a result of expanding global markets for pulp, timber and oil palm are among the major causes of this massive loss in forest cover," Yiyuan Qin, a research analyst for the WRI’s Natural Infrastructure for Water project, wrote.
According to Qin, the massive loss of forest cover has made the land more vulnerable to both flooding and drought, and contaminated its water supply, as the land lost its natural ability to regulate the water flow and filter it.
Sumatra has suffered from more floods, landslides, forest and peat fires and water pollution thanks to uncontrollable forest clearing activities.
What happens in Sumatra reflects what has been happening around the globe. Forest degradation has threatened water security everywhere as natural infrastructures — such as upstream forests and wetlands — are stripped and the soil can no longer filter water naturally.
"The world’s watersheds lost 6 percent of their tree cover on average from 2000-2014, putting citizens at risk of losing their water supplies,” Qin said, adding that watersheds face the most danger from forest cover loss, fires and erosion.
Establishing conservation zones, engaging in agroforestry and other sustainable forestry practices are some approaches Qin and her team suggested to mitigate watershed damage.
In the watershed of Krishna, India, only 3 percent of its trees remain, leaving the area more prone to frequent droughts and floods, with high levels of water pollution — thanks to urbanization and cropland expansion.
Meanwhile in the Philippines, erosion caused by expansive agriculture is the main threat for the Southern Leyte watershed, making the area more susceptible to landslides.
In Angola, not only are fires there killing off trees, they have also contaminated the water supply and interrupted its flow to many communities.
To improve water security at risk from forest cover loss, fires and unsustainable land use, WRI launched the Global Forest Watch Water to educate the public about the importance of protecting water supplies.
The platform also provides data sets, statistics and risk scores of 230 watersheds around the world.