Flood Threat Remains Large

KOMPAS/VIDELIS JEMALI

Houses stand partially buried on Monday (4/29/2019) in mud, silt and tree debris reaching a height of 3 meters that were carried by a flash flood in Bangga village of South Dolo district, Sigi regency, Central Sulawesi. No fatalities were reported, but the villagers lost many of their personal possessions in the flood, which was caused when nearby rivers overflowed.

Heavy and extreme rains happen more often in line with climate change. Changing weather patterns increase the risk of floods, flash floods and landslides.

JAKARTA, KOMPAS — Heavy rainfall (more than 50 millimeters per day) and extreme rainfall (more than 100 millimeters per day) over the past week have caused flooding and landslides in at least 26 cities and regencies in nine provinces. The threat of floods and landslides remain, especially in regions with degraded vegetation, as heavy rainfall is expected to continue through the first week of May.

Following flooding and landslides in Greater Jakarta, the disasters also hit Bengkulu, Lampung, West Kalimantan, Central Kalimantan, North Sulawesi, South Sulawesi, East Java and Central Sulawesi. By Monday, 34 people had been killed and six others were missing.

A flash flood on Sunday (4/28/2019) hit four villages in Gumbasa and South Dolo districts in Sigi regency, Central Sulawesi. No casualties were reported, but one village was buried in mud and silt carried by the overflowing Bora River. The mudflow reached 3 meters high, inundating most homes to the roof. The flash flood left mud and tree debris in three other villages.

This was the second flash flood in six months, with the first occurring on Nov. 28, 2018. Local residents said the flash flood was more severe this time. The flash flood followed two days of heavy rains that fell in Sigi on Saturday and Sunday.

“I stayed on top of my house for two hours until the search and rescue [SAR] team arrived to evacuate me,” Bangga villager Irman, 36, said on Monday (4/29).

Bangga village was worst hit by the flash flood. Sigi Regent Irwan Lapatta said at the site of the flooding that the mud and silt carried by the river very likely came from the mountain. The earthquake on Sept. 28, 2018 was believed to have caused the landslide.

In Central Kalimantan, 13 villages in eight districts in Kapuas, Pulang Pisau and Lamandau regencies were flooded. Huts and docks on the Batang Kawa River, a tributary of the Lamandau River, were inundated to their rooftops. The villagers believed that the flood was a result of converting forests into plantations. Kubung village secretary Tamel of Kudangan district, Lamandau regency, said, “We have never had floods. This is the first time.”

Floodwaters in several regions, including Bengkulu and Manado, North Sulawesi, began to recede on Monday. Around 50 percent of the 12,000 people, who were evacuated in nine regencies and cities in Bengkulu, have returned to their homes. They urgently need assistance like food, medicine, clothing and construction materials to repair their damaged homes.

BPBD TANA TORAJA

Search and Rescue personnel navigate a rubber dinghy on floodwaters as they rescue local residents. Flooding hit several regencies on Monday (4/29/2019) in South Sulawesi, including Tana Toraja, North Toraja, Enrekang, and North Luwu.

Bengkulu Disaster Mitigation Agency (BPBD) emergency response head Syamsudin said this was the biggest flood the region had seen in 30 years. “Almost all regions in Bengkulu are now flood-prone. Only Muko Muko was unaffected,” he said.

By Monday, 28 people in Bengkulu had been killed in the flood, while six people remained missing.

Six people were killed during a landslide in Pesisir Barat regency, Lampung, while flooding in South Lampung inundated around 300 homes.

Train delays

Flooding in the East Java city of Pasuruan has caused delays of 40-229 minutes to the train service in eastern Java. Fast-flowing floodwaters carried away ballast and soil from the tracks, which were submerged in water 5-15 centimeters deep.

“In the last four years, the railway has been flooded several times. However, this is the most severe, as it has damaged the track and caused delays to the rail service,” said Luqman Arif, the spokesperson of state railway operator PT KAI’s Jember branch.

ANTARA FOTO/UMARUL FARUQ

Motorcyclists drive on the Lapindo mud embankment on Monday (4/29/2019) to avoid floodwaters in Porong, Sidoarjo, East Java. The Porong highway was inaccessible to motorcyclists, as it was submerged in floodwaters 60 cm high due to high rainfall since Sunday evening (4/28/2019).

Monitoring data at the Meteorology, Climatology and Geophysics Agency’s (BMKG) shows that the intense rainfall had moved on Sunday and Monday to the central and eastern parts of the county. The maritime meteorology station in Paotere, South Sulawesi, recorded the highest rainfall intensity at 107 mm per day. Rainfall of more than 50 mm per day continued in eastern Java, southern and northern Kalimantan, northern and central Sulawesi and the Bird’s Head region of West Papua.

The regions forecast for heavy rainfall until May 2 include Java, Bali, East Nusa Tenggara, North Kalimantan, East Kalimantan, Sulawesi, North Maluku, Maluku, West Papua and Papua.

“These regions, especially Sulawesi, Kalimantan and Papua, are climatically still in the rainy season,” said BMKG climate and air quality information head Siswanto.

Heavy rainfall of more than 60 mm was recorded in western Flores. “This is an anomaly, as the MJO [Madden-Julian Oscillation] moving from west to east is colliding with dry easterly winds from Australia. It has resulted in air currents that have led to increased rainfall, including in East Nusa Tenggara, which should be entering the dry season,” said Siswanto.

He said the extreme rainfall anomaly was part of the changing rain patterns in Indonesia. Siswanto’s research showed that daily rainfall patterns were changing to more than 50 mm and 100 mm. The trend had been increasing significantly from 1961 to 2010, in line with the sharp temperature increase over the period.

ANTARA FOTO/UMARUL FARUQ

A transfer dump truck braves floodwaters covering the Porong highway on Monday (4/29/2019) in Porong, Sidoarjo, East Java. Heavy rains since Sunday evening (4/28/2019) caused floodwaters up to 60 cm high to inundate the highway.

Siswanto said that the risk of flooding in Indonesia would only increase due to the changing trend. Disaster hazards had also increased in line with environmental degradation and higher residential density on floodplains.(AIK/IDO/OKA/VIO/GER/TAM/REN/NIK/RAM/ESA/VDL)