The Sumatran Disaster Is a Real Proof of Environmental Degradation

JAKARTA, KOMPAS – The disasters of flooding, flash floods, and landslides that have struck Aceh, North Sumatra, and West Sumatra are not only caused by natural factors but also by human actions. Areas that should serve as water catchment zones have been converted into plantations, agricultural land, and mining sites. The disaster, which has claimed more than 300 lives, serves as a stark evidence of environmental degradation.

As of Sunday (30/11/2025), several access routes in the three provinces remain cut off. Thousands of residents have been forced to evacuate. The community is also overshadowed by concerns of subsequent disasters, considering that heavy rain still has the potential to occur.

Hydrology expert from Padjadjaran University, Chay Asdak, stated that environmental degradation also contributes to the disaster. The impact of the disaster triggered by tropical cyclones Senyar and Koto has become increasingly severe.

"If there is no environmental degradation, it is impossible for there to be a major flood that brings mud and logs from upstream. One of the causes of this degradation is land conversion," he stated when contacted in Jakarta on Sunday afternoon.

Lands in the mountains or hills can no longer hold back the flow of water during heavy rains. As a result, most of the water flows over the surface of the ground, triggering floods. The high concentration of water on steep land is very vulnerable to landslides.

Therefore, land use permits must be tightened and analyzed carefully. According to Chay, national development programs should not be burdened by activities that damage the environment.

"Permits must also consider disaster management. Therefore, the principle of precaution should not be overlooked. We should not only view it from the perspective of the disaster itself but also the land use policies that have been in place."

Chay stated that the policy applies to several sectors, such as forestry, agriculture, plantations, and energy and mineral resources (ESDM). Land use is often linked to timber production, food estates, oil palm plantations, and mining.

We should not only look at the disaster side, but also the land use policies that have been implemented so far.

"This is not to blame any party. However, we can see that even legal actions can lead to greater disasters if their implementation is not meticulous," he said.

Therefore, ministries in each sector need to reassess the policies that have been implemented. Disasters that have claimed many lives should serve as a momentum to improve land use, especially in water catchment areas.

"Just focus on anthropogenic factors. I am concerned that if the national program is misused, the damage it can cause could be much greater. In the end, it is the community that will bear the losses," he explained.

Chay added that regarding natural factors, information about the potential for extreme weather is expected to be communicated to the public in a timely manner. This way, residents and local governments can build preparedness to minimize its impacts.

"Disasters do not come with a sense of timing. It is not only natural factors; policies that can trigger environmental degradation must also be taken into account. The government must be more sensitive in anticipating the impacts. How much longer will we wait?" he stated.

A lecturer from the Geodesy and Geomatics Study Program at the Bandung Institute of Technology (ITB), Heri Andreas, explained that flooding is not solely about rainfall, but also how water is received, absorbed, and managed by the earth's surface. Environmental degradation, changes in land cover, and the decreasing capacity of areas to hold water are significant factors that exacerbate the impacts of flooding.

"When precipitation falls, some water seeps into the ground (infiltration), while the rest flows over the surface as runoff. The proportion between the two depends greatly on land cover and soil characteristics," he explained.

Heri added that areas with natural vegetation cover, such as forests and swamps, have a much higher water absorption capacity than areas that have been converted into residential areas, plantations, or open areas without vegetation. When these areas are degraded, their infiltration capacity decreases significantly, leading to a much greater increase in runoff.

"When natural water retention areas disappear, the region loses its ability to absorb runoff. As a result, rainwater flows quickly into the rivers and triggers flooding," he stated.

The disruption of several access roads due to flooding and landslides has hindered the distribution of logistical assistance. As a result, logistical aid for several areas that remain isolated must be distributed via air routes.

In North Sumatra, thousands of residents have been displaced at various locations due to damaged settlements and disrupted access. The number of refugees has reached thousands in South Tapanuli and the city of Sibolga, as well as hundreds to thousands of households in Mandailing Natal, North Tapanuli, and Humbang Hasundutan.

Transportation access in this region is largely damaged. The national routes of Sibolga–Padang Sidempuan and Sibolga–Tarutung have been completely severed and blocked by landslides at many points. Several bridges, including the Pandan Bridge and the bridge on the Sibolga–Manduamas road segment, have also been cut off.

Several district routes have also been cut off and have not yet been repaired due to difficult terrain. In Mandailing Natal, at least seven areas are isolated due to the closure of interprovincial routes, while some villages can only be accessed using heavy equipment or air transportation.

To expedite the response, the National Disaster Management Agency (BNPB) and various ministries/agencies have deployed various main weapon system tools (alutsista), including five support helicopters stationed at Silangit Airport for logistics distribution to Central Tapanuli and other isolated areas. "For instance, Sibolga, as of the third day of the emergency response, we have not been able to reach it by land, but we can access it by air for logistics distribution," said BNPB Head Suharyanto in a press statement.

In Aceh, the damage to bridges and national roads has resulted in the disruption of main access routes, including the Banda Aceh–Lhokseumawe route and the Aceh–North Sumatra border route in the Aceh Tamiang area. Until now, several regions such as Gayo Lues, Aceh Tengah, and Bener Meriah remain inaccessible by land routes.

The National Disaster Management Agency (BNPB) has activated emergency communication support using satellite networks in several locations, particularly in areas where telecommunication networks are disrupted. Logistics delivery is carried out by air using helicopters and Cessna Caravan aircraft to reach areas that remain isolated.

Several provincial and national roads in West Sumatra have also been cut off due to landslides and damaged bridges. The Caravan aircraft and Bell 505 helicopters have been deployed to support the distribution of logistics to areas that are not yet accessible by land.

President Prabowo Subianto stated that the government continues to monitor the natural disasters affecting several regions in Sumatra. Assistance will be continuously sent to the residents impacted by the disasters.

"We continue to monitor. We continue to send aid. We will assess the situation later," said President Prabowo (Kompas, November 30, 2025).