Extreme Rainfall in Padang Beats Jakarta's 154-Year Record

Rainfall in Padang City on Thursday (7/3/2024) was recorded as extreme, reaching 394.6 millimeters per day.

The following article was translated using both Microsoft Azure Open AI and Google Translation AI. The original article can be found in Curah Hujan Ekstrem di Padang Mengalahkan Rekor 154 Tahun di Jakarta

BPBD PADANG PARIAMAN

The process of evacuating deceased victims who were buried in a landslide in Padang Pariaman Regency, West Sumatra, took place on Friday (8/3/2024).

JAKARTA, KOMPAS — At least 21 residents died and five people went missing as a result of the floods and landslides that hit a number of areas in West Sumatra since Friday (8/3/2024). This was triggered by high rainfall in the area with the highest occurring in Padang City.

The Meteorology, Climatology and Geophysics Agency (BMKG) recorded high rainfall in West Sumatra with the highest occurring in Padang City, reaching 394.6 millimeters per day, from Thursday to Friday ( 7-8/3/2024).

According to the Head of the BMKG Public Meteorology Center Andri Ramdhani, in Jakarta on Monday, based on mapping in West Sumatra, moderate to heavy rain dominated most areas of this province from Thursday to Friday last week.

"Rain with very heavy intensity commonly occurs in the areas of the west coast of West Sumatra," he said. "Rain is categorized as very heavy if it has an intensity or precipitation of 100-150 millimeters (mm) per day," he added.

Andri added that extreme intensity rain was also recorded at eight observation stations in this province. Rain is categorized as extreme if it has a precipitation of more than 150 mm per day.

BMKG

Rainfall data at several rainfall observation posts in West Sumatra from Thursday to Friday (8/3/2024). Source: BMKG.

Note from BMKG states that the highest recorded extreme rainfall intensity was at Bandar Buat Station in Padang, reaching 394.6 millimeters per day. Next, rainfall with an intensity of 368.4 millimeters per day was recorded at the Minangkabau Meteorology Station in Padang Pariaman.

Heavy rain with a very intense intensity commonly occurs in the areas along the west coast of West Sumatra.

Rain with an intensity of 328 mm per day was recorded in Pos Sasak, Padang Pariaman, and in Pos Terusan, Pesisir Selatan, with 320 mm per day.

Also read: Flood, Alarm from Nature

According to Andri, the intensity of rainfall in the city of Padang and some areas of West Sumatra is likely the highest in Indonesia. The amount of rainfall also exceeds the record amount that occurred in Jakarta at the end of 2019.

Exceeding Jakarta's record

The data shows that the intensity of rainfall in Padang City is higher than the highest recorded rainfall of 377 mm per day in Jakarta's 154-year history of recording, which was recorded in Halim, East Jakarta, on December 31, 2019.

The intensity of the rainfall in Jakarta at that time triggered a major flood that affected 31,200 residents towards the end of the year.

According to climate expert Siswanto of the BMKG, rainfall intensity records in Jakarta have been conducted since the 1840s by the Dutch, but the data has only been properly organized since 1866.

The highest recorded rainfall in Jakarta previously reached 367 mm per day in Sunter in 2015. The extreme rain in Jakarta at that time was categorized as weather anomaly due to the continued warming of the surface air as a result of climate change.

KOMPAS/RIZA FATHONI

Location of the Ciliwung drainage gate at Kali Cipinang, East Jakarta, on Tuesday (1/14/2020). The Ciliwung drainage gate was built to channel water from the Ciliwung River to the East Flood Canal, which is expected to become one of the solutions to overcome floods.

Rising temperatures due to climate change are changing rainfall patterns. Siswanto's study in the journal Royal Meteorological Society (2015) stated that in 1866-2010, the number of rainy days in Jakarta decreased, but the proportion of heavy rainfall exceeded 50 mm per day and 100 mm per day in total annual rainfall. rose significantly.

So, even though the annual rainfall accumulation is decreasing, the frequency of extreme hourly or daily rainfall is increasing.

According to Siswanto's study published in the Meteorological Society of Japan journal in February 2022, an increase in surface temperature in Jakarta and its surroundings of 1 degree Celsius in the last 100 years increased the air's ability to hold water by up to 14 percent, double that of which is understood globally.

Ocean temperature anomalies

Head of the Minangkabau Meteorology Station in Padang Pariaman, Desindra Deddy Kurniawan, stated in his report that based on satellite imagery, the presence of convective clouds in the West Sumatra region was observed since Thursday at 3:00 PM.

The presence of convective clouds continued to develop and entered the area of Padang City at 5:00 PM with the peak temperature of the cloud reaching minus 80 degrees Celsius. This condition indicates the presence of convective clouds that can trigger heavy rain accompanied by lightning in the area.

Also read: 21 Residents Died due to Floods and Landslides in West Sumatra, 5 Others Disappeared

According to Desindra, the Madden-Julian Oscillation wave, which usually contributes to high rainfall, is currently not present in the western region of Indonesia, therefore not contributing to the formation of rain clouds in West Sumatra.

BMKG

Rainfall patterns in several rain observation posts in West Sumatra from Thursday to Friday (7-8/3/2024). Source: BMKG.

However, the indicator of anomalous sea temperature shows an increase of 1-3 degrees Celsius. This triggers the potential for evaporation or the addition of water vapor mass in the western Indian Ocean of Sumatra, thereby increasing the amount of water vapor mass.

Analysis of the 3000-feet air layer shows a convergence of air masses and a significant slowing down of wind speeds in the West Sumatra region. This has resulted in the buildup of air masses in West Sumatra and has supported the growth of convective clouds in the area.

Meanwhile, the analysis of air humidity sourced from data from the Minangkabau Meteorological Station on March 7, 2024 indicated that the air was in a wet state from the lower to higher levels. This shows the potential formation of convective clouds in the West Sumatra region.

Desindra concludes that the extreme rain in Padang City and its surrounding areas was caused by the meeting of air masses accompanied by a significant slowing down of wind speed. "The sea surface temperature in the western waters of West Sumatra is warm and the humidity of the air is high in both the lower and upper layers," he said.

Based on satellite and radar image data, heavy rain with long duration occurred from daytime until nighttime. This condition caused the rain catchment area to be unable to accommodate the very high rainfall which resulted in flooding and landslides.

Takes lives

Head of the Center for Disaster Data, Information, and Communication of the National Disaster Mitigation Agency (BNPB) Abdul Muhari stated that the floods and landslides in West Sumatra since last Thursday have caused fatalities.

In total, the disaster has claimed 19 lives, injured 2 people, and left 7 missing. It also affected tens of thousands of individuals. It has recently been reported that the death toll has risen to 21 people, with 5 still missing.

DOKUMENTASI WARGA

Condition after the flash flood in Kampung Langgai, Nagari Ganting Mudik Utara Surantih, Pesisir Selatan, West Sumatra, on Friday (8/3/2024).

Based on information from the Operations Control Centers (Pusdalops) of BNPB, 10,150 families or 35,299 people in the city of Padang were affected by the flood. In the South Coastal Regency, there were 16 fatalities, 7 missing persons, and 25,794 families affected by the flood.

In Padang Pariaman Regency, there were 3 deaths, 2 injured residents, and 800 families or 2,958 people affected.

In the city of Solok, 238 families or 813 individuals were affected. In the district of Limapuluh Kota, 24 families or 100 individuals were affected. In the district of Agam, 36 families or 144 individuals were affected.

Also read: How Floods Can Increase the Risk of Death Even if They Have Passed

Meanwhile, in Solok Regency, 10 families were affected. In West Pasaman Regency, 31 families were affected, and in Pasaman Regency, 191 families were affected.

"The flood and landslide incidents forced residents to evacuate. In the Padang area, 3,734 individuals were displaced; in the South Coast District, 29,483 families or 76,178 individuals were displaced; and in the Agam District, 49 families or 209 individuals were displaced," said Muhari.

Floods and landslides have resulted in material losses in western Sumatra, with 37,265 housing units affected. 666 homes have been damaged, 3 swept away, 26 bridges damaged, 45 places of worship flooded, and 25 schools submerged.

In addition, 13 road sections are affected, 2 irrigation facilities are damaged, 113 hectares of land are affected, as well as 5 public facilities are affected by flood and landslide disasters.

BPBD PESISIR SELATAN

The road conditions collapsed due to flooding in Pesisir Selatan, West Sumatra, on Friday (8/3/2024).

Based on information from officials at the Regional Disaster Management Agency (BPBD) of West Sumatra, Gilang, efforts to handle flooding and landslides are still ongoing. As of Sunday, access to the main road for residents going to and from Kotamenara Village in Padang Pariaman Regency is still blocked by a landslide that stretches for 50 meters.

Floods in Agam Regency, Pesisir Regency, and Solok City are gradually receding. In South Pesisir Regency and Padang City, most of the flood-affected areas are still submerged in water. In Limapuluh Kota Regency, the floods are gradually receding. Cleaning of houses and public facilities that were inundated has been carried out.