In October, several areas in Indonesia have transitioned to the rainy season, including Jakarta. Based on the monitoring of sea surface temperatures in the central and eastern Pacific Ocean, the Meteorological, Climatological, and Geophysical Agency (BMKG) noticed that the anomaly value has passed the La Niña threshold, which is -0.61 in the first ten days of October 2021.

If we look back to 2020, La Niña brought an increase in rainfall in November-January in Java, southern Sumatra, Bali, NTT, southern Kalimantan and southern Sulawesi. This year, the condition is predicted to be relatively the same and will have an impact on an increase in monthly rainfall ranging from 20%-70% above normal. This increase in rainfall requires us to prepare for hydrometeorological hazards or disasters.

La Niña and the Hydrometeorological Disaster

During the interview with Dr. Ir. Dodo Gunawan, DEA, Head of the BMKG Climate Change Information Center, Dodo explained, La Niña is an interaction between the ocean and the atmosphere that occurs in the Pacific Ocean. When La Niña occurs, the temperature in the Pacific Ocean is relatively cold, while the waters or seas around Indonesia are relatively warmer. This condition causes a lot of cloud formation which eventually causes rain. As a result, during La Niña, the intensity of rainfall in Indonesia is increasing. La Niña usually occurs every few years and each event can last from a few months to two years.

This year, La Niña in Indonesia has the potential to develop with weak to moderate intensity until February 2022. In addition, monthly rainfall is estimated to increase between 20%-70% above normal. Reflecting on last year's events, an increase in rainfall could potentially lead to hydrometeorological disasters such as floods, extreme rainfall, and landslides. Hydrometeorological disasters are disasters caused by meteorological parameters such as wind, rainfall, humidity, and temperature.

[All About La Niña: What is it and What You Can Do]

Lessons Learned and The Impact of La Niña in Jakarta

Accurate La Niña predictions can provide early warning and anticipation of hydrometeorological disasters. This prediction can also help us to reduce the losses and costs incurred by hydrometeorological disasters. In early 2020, the Greater Jakarta area experienced high rainfall. The water level in Jakarta was 10-350 centimeters and it took around one to four days for the water to subside.

This year, Jakarta provides ombrometers in 267 areas. Previously, the ombrometer was only installed in 10 areas. This ombrometer is used as a reference to anticipate flooding during extreme rains, so if the numbers shown by the ombrometer have the potential for flooding, both the government and citizens can perform mitigation measures. Not only providing an ombrometer, Jakarta continues to implement the river normalization programs, building vertical drainage, and optimizing the use of water pumps.

[How To Anticipate Flood During Rainy Seasons]

Stay Safe From Hydrometeorological Disasters with JAKI

To find out the condition of the water level at the floodgates and observation posts in Jakarta, you can use JakPantau on JAKI. There’s also access to flood information around the neighborhood in this feature. In addition, JakWarta feature will periodically send early warning notification to your smartphone. This information consists of rain intensity, water level status, and areas that are predicted to rain. All available information is sourced from the BMKG which is forwarded by the Jakarta Regional Disaster Management Agency (BPBD). Not only that, if you see a condition that causes a disturbance after a heavy downpour, you can send a report via JakLapor to get proper treatment from the officers. To get these features, download JAKI and head over to the App Storeor Play Store.