Study links Bahorok flood to illegal logging

Muninggar Sri Saraswati, The Jakarta Post, Medan

An investigation by the Leuser Management Unit (UML) concluded over the weekend that the recent flash flood that swept through a North Sumatran resort town, which claimed hundreds of lives, was an indirect result of the rampant deforestation of Mount Leuser National Park.

The UML is a European Union-funded organization comprising environmentalists and government institutions for the preservation of the Leuser ecosystem.

The conclusion was made following an analysis of video footage taken at Bukit Lawang resort several days after the incident and a topographical map of Langkat regency covering 250,000 hectares of forest areas.

The forests in the regency belong to the 950,000 hectare National Park, most of which is located in the southeastern part of Aceh province.

The footage, taken early on Monday, revealed dozens of landslides upstream of the Bahorok River, which flows through Bahorok town on the slopes of Mount Leuser.

The mud from the landslides had flowed across several hills, located at an altitude of between 1,200 to 2,000 meters above sea level. Thousands of trees had toppled along the riverbank and into the river.

The mud and trees had created dozens of small dams and several large dams.

UML advisor Mike Griffiths said the dams had blocked the river and it was likely that they could no longer hold back the water when heavy rains fell upstream of the Bahorok River a day before the flash flood.

The North Sumatra Meteorology and Geophysics Agency (BMG) recorded 66 millimeters of rainfall on Saturday, two millimeters on Sunday and nine millimeters on Monday. It had warned of possible heavy rains at the beginning of the rainy season.

Griffiths warned of the possibility of similar flooding recurring in the area.

There are more than 150 tributaries that flow into the Bahorok River. All of the rivers in the upper side are located in Aceh.

The National Park mainly consists of steep, almost inaccessible montane forests. However, illegal loggers have poached and deforested several areas in the park.

UML spokesman Deny Purba said over the weekend that some 42,000 hectares of the park in Langkat regency was now barren land, most of which was located 50 kilometers or so above Bukit Lawang resort.

It is estimated that 50 percent of the deforested area, or critical land, is the result of illegal logging. The other 50 percent is a consequence of illegal occupation of the land by Acehnese refugees who fled to the park following the political turmoil of 1999-2001.

The illegal logging is mostly carried out by local people who sell the timber to a wood and pulp company owned by a notorious businessman, he added.

"The company lends bulldozers and chain saws to poach trees inside the park," he said.

It is common knowledge among locals that the businessman -- whose name Deny declined to disclose -- has close ties with local security and administration officials, including councillors.

The businessman, who started his business in the 1990s, is also known to smuggle oil, and has often been nabbed by police for his illegal activities. However, he always managed to escape prosecution due to his relationship with influential local figures, Deny added.

He said the critical land was located in the same river basin of the Bahorok River -- the Wampu river basin -- that was hit by the flash flood last Sunday.

Bambang Hero Saharjo, a forestry expert at the Bogor Institute of Agriculture, explained that the disaster was an indirect result of the partial destruction of the Leuser ecosystem.

"The soil is not stable and shifts incrementally, invisibly. The destruction of a particular location within a single ecosystem will harm other parts of the ecosystem," he said, pointing out that the Leuser ecosystem had porous soil and steep hills, which raised the potential for flooding.

He explained that "the poor soil from the barren land above Bukit Lawang spread to the resort area and weakened the tree roots in Bukit Lawang".

"People always mistakenly think that a natural disaster has nothing to do with the destruction of forests by man," said Bambang, who often testifies as an expert witness in forest destruction cases.

Bambang repeatedly warned that the Leuser ecosystem, just like any other ecosystem in the world, could not withstand deforestation, no matter how minimal.

"The Bahorok tragedy teaches us that nature can no longer bear human exploitation. We can do nothing against the anger of nature."