West Sumatra experienced recent floods and landslides. In Agam floods and landslides killed a resident. The Regent of Agam declared a disaster emergency response for 15 days, 13 to 27 July 2023. Padang Pariaman Regency, too, was flooded last July 14 so that more than 1,000 residents’ houses were affected and 85.5 hectares of rice fields were reported submerged.
Seeing that several areas in West Sumatra were experiencing disasters at almost the same time, BNPB immediately sent a team to West Sumatra led by Acting Main Secretary, as well as Director of Emergency Resources Support, Rustian to coordinate and accelerate steps for handling the 15 July disaster.
The BNPB team had a coordination meeting with the Governor of W Sumatra, the Mayor of Padang, the Regent of Padang Pariaman and the Head of Implementers and Regional Apparatus Organizations in W Sumatra.
From that meeting, BNPB will provide operational funding assistance and equipment logistical support to the affected regional governments. The BNPB team also conducted a joint visit with local government representatives to Air Manis Village, Padang City and Lubuk Sekoci Village, Padang Pariaman.
Abdul Muhari, Head of the BNPB Disaster Data, Information and Communication Center, said that the points of disaster occurrence were mostly repeated in the last 10 years.
As long as there are no significant changes in the context of land use, ecosystem rehabilitation or replanting of water catchment areas, he said, maybe these areas will still be the biggest contributors to disasters.
Initially, West Sumatra was not a concern because the BMKG weather forecast on the second floor of July did not specifically mention that the area of origin of this rendang dish would be subject to major flooding. They see potential in Eastern Indonesia, namely Maluku, Sulawesi and Papua.
He said, there is the influence of the Madden-Julian Oscillation (MJO), which is a non-seasonal wave or oscillation in the troposphere moving from west to east for 30-60 days. This phenomenon, he said, had an impact on the anomalous conditions of rainfall in the areas it passed.
In addition, he said, there are several regional conditions. MJO, he said , is like a series of train movements of rain clouds from the East Coast of Africa or to the west of the Indian Ocean and then shifts along the equator. “It takes two to three weeks to pass through Indonesia. Now its position is in Indonesia all the way to the East,” he said.
Even so, on the other hand there is the formation of tropical cyclones north of the Philippines. Once there was a big rain cloud, he said, the cyclone would suck it in. So, it’s as if the clouds are drawn to the east and get lots of rain clouds.
“So, this condition depends on regional weather. Because we are a maritime nation, the island is influenced by the Pacific and Indian oceans which causes the seasonal pattern to be not absolute, meaning that the rainy season does not have to be wet or vice versa. So, there are regional phenomena that bring or attract rain clouds so that the weather changes are very dynamic in Indonesia.”
Muhari appealed to the local government to be vigilant because there is still the potential for low to moderate rain which might have an impact on natural disasters. “Such as aftershocks such as West Pasaman, Pasaman, Agam and South Coast and Mentawai.”
In addition to flooding, West Sumatra is also prone to landslides, such as on Mount Padang, in Agam, South Coast and Mentawai districts.
Agam is prone to landslides, he said, because this is a volcanic area so when it rains large boulders slide down and hit the house. “Because of the topography as well.
Muhari said that climate change in Indonesia is so dynamic. The time span until the end of August, which should have been the peak of the dry season, instead experienced wet hydrological disasters such as floods and extreme weather.
Therefore, vigilance does not only focus on wet and dry hydrological disasters.
For people who live along river banks or are quite far away or who live in areas that are steep and have sufficient vegetation, they must really pay attention to natural conditions.
He urged residents to immediately evacuate independently. “Don’t wait for the local government to order an evacuation.”
Disaster in Bali
The island of Bali was not spared from floods and landslides. Karangasem Regency on the eastern tip of Bali Island, was recorded as the area with the most disasters this July.
In early July, Bali was hit by hundreds of disasters in all districts which were sparked by two days of heavy rain. The vulnerability of this small island is increasing.
Based on the latest Bali BPBD recapitulation data, during 2023, until July 10 there were 353 disasters, the most in Karangasem, 129 incidents. After Karangasem, followed by Tabanan, then Gianyar and Badung.
The Bandung Institute of Technology (ITB) Research and Community Service Institute held a focused discussion on disaster and education in Karangasem 20 July 2023.
Edi Riawan, an ITB hydrometeorology researcher, said that in October 2022 there was heavy rain in Bali. On October 19, it was recorded that rainfall was above 100 mm per day. There is a trend of increasing rain and wind.
He said, in 1975, the rainfall discharge in Denpasar had reached 350 mm. A repeat with a probability of five years could occur.
Extreme weather, he said, is not only measured by statistics on the frequency of occurrence, but also by the potential damage that occurs. One type of extreme weather in Indonesia is heavy rain with a minimum intensity of 50 mm per 24 hours or 20 mm per hour.
IB Ketut Arimbawa, Head of the Karangasem BPBD, said that this district has the highest threat of disaster.
Since the flash floods last July 6-10, many flood early warning devices have been damaged, for example in Yeh Seh. Also, homes and school facilities. From BPBD data, at least three residents died due to landslides this July.
He admits that mitigation is still minimal, for example, there is reinforcement of bridge leaning but when heavy rains it erodes. “During the summer the river is dry but when it rains it floods,” he complained.
A number of efforts were made, he said, through disaster preparedness education focused on earthquakes and eruptions. Then the disaster resilient village program or Desatana already exists in 10 villages.
They have also provided the latest disaster risk maps to spatial planning for example six km from the mountain should not be inhabited.