Written by May Nelsa Putri Ritonga, VDMS grantee from North Sumatera University (USU), Medan

As is generally known, 70% of the surface area of ​​the earth is covered by water, and 2/3 of the human body is water so water is important. But problems of water began to appear, such as the severe drought during the dry and flooding during the rainy. And one contributing factor is the destruction of forest (deforestation). One of impact is no balanced due absorption capacity to water volume adding. For example one of them is Bohorok River’s flood in 2003. Allegedly this happened because of flash flooding rains constantly and plus rampant illegal logging in the forest TNGL (Gunung Leuser National Park) as found many logs (trunks of felled trees) are carried on the water.

The average consumption of water by moist tropical lowland forest is about 1,415 mm per year, while the mountain forest that lies at an altitude of about 1,750 mm above sea level water consumption amounted to 1,225 mm. If we see the consumption of agricultural crops is only about 1.100-1200 mm. So if the forest was conversion into agricultural land, amounting to 200-300 mm of water per year will increase the river flow could do flooding because the forest’s ability to manage water is going down.

Basically, the forest is like a giant sponge that can absorb rainwater during the rainy season and do slowly be released back in the dry season. Rainwater will be patch in the crowns of trees or in the litter and do a process to vaporize back into the air before the water to soil surface. Litter and undergrowth will also reduce the flow rate of water on the soil surface and withstand drops of water that fell from the leaves to protect water quality by minimizing erosion and reduce sediment. By which makes the concentration of sediment in the water that flows be higher and siltation (puddling) streams.

So let us all begin to realize how important it is to keep the forest for our water supplies. The water is sourced from a forest area will flow not only in forest and the surrounding areas, but also under the forest area will be utilized in everyday life. Stop illegal logging! Damaged forests can cause great disaster for all of us.

A2A E – Newsletter Vol. 61| III | 2017