Rainfall Intensity Increases

KOMPAS/RIZA FATHONI

An employee of the East Jakarta Parks and Funeral Service Officer cuts Angsana tree branches on Jalan Lingkar Duren Sawit, East Jakarta, Monday (25/2/2019). Besides reducing branches that disrupt electrical wires, the tree branch pruning is also intended to prevent the trees from collapsing due to strong winds during the rainy season.

JAKARTA, KOMPAS —The intensity of the rain is expected to increase this month and it has the potential to trigger hydrometeorological disasters, especially floods and landslides. This phenomenon is set to last until next week, especially in Sumatra and western Java.

The increase in rain was triggered by the Madden Julian Oscillation (MJO) movement in the Indian Ocean. The atmospheric wave, which carries a wet air mass, has moved from the west around the Indian Ocean to the east and it could increase the potential for rainfall in the area it passes through.

In addition to the MJO, from the analysis of wind movement patterns, the Meteorology, Climatology and Geophysics Agency (BMKG) has also detected the presence of cyclonic circulation in the western Indian Ocean side of Sumatra, which forms a meeting area for wind in Sumatra, Central and South Kalimantan as well as Java.

“The increase in rain will gradually reduce drought in some areas, such as Riau. In April, this area will get rain before the dry season returns,” said BMKG climate and air quality information production subdivision head Siswanto in Jakarta on Sunday.

Early warning

BMKG meteorology division deputy head Mulyono R Prabowo has issued an early warning to the public to be aware of the potential for hydrometeorological disasters. “We have observed a number of atmospheric phenomena simultaneously. This can for increase the potential for high rainfall,” he said.

The BMKG appealed to the public to remain vigilant this month because high rainfall has the potential to trigger hydrometeorological disasters,

such as floods, landslides, flashfloods, inundations, high winds, fallen trees and slippery roads. “This condition could increase in mid-March,” Mulyono said.

According to Mulyono, the regions that could be affected include West Sumatra, Jambi, Bengkulu, South Sumatra, Lampung, almost all of Java, Bali, West Nusa Tenggara and East Nusa Tenggara, Kalimantan, Sulawesi, Maluku, West Papua and Papua.

Yesterday, an intense downpour soaked Jakarta and surrounding areas. Due to the impact of the rain, the Central Office of the Ciliwung Cisadane River Region (BBWSCC) is monitoring the water levels of a number of rivers. Based on data from the BBWSCC at 9 a.m., a number of rivers in Jakarta were declared safe because they were on standby status or lower than the 150-centimeter limit. “Although it is safe, we will continue to monitor the sluice gates,” said BBWSCC water resources maintenance officer Eka Siwi Agustiningsih.

West Jakarta Water Resources Office head Imron Syahrin said the water levels in the Angke and Pesanggrahan rivers have increased by 20 cm.

Imron added that to overcome flooding his office relied on a number of water pumps spread across West Jakarta. For example, water from the Cibubur River, which is located close to houses in the Tambora subdistrict, will be sucked up by a water pump and transferred to the Duri River.

Earlier this year, intense downpours triggered floods and landslides in a number of areas. For example, landslides in Cisolok, Sukabumi regency, West Java, killed 30 people.

In mid-January, floods hit four subdistricts in Bandung regency, as well as North Aceh, Aceh, and Cilacap regencies.

High rainfall also caused massive flooding and landslides in seven regencies and cities in South Sulawesi. Early last month, floods hit Manado in North Sulawesi.

High waves

In addition to heavy rains, according to the BMKG, waves of between 2.5 to 4 meters are also set to hit Central and East Java, the southern part of the Bali Strait, the western Indian Ocean side of the Mentawai Islands to Lampung, as well as the southern Indian Ocean side of Java and Bali.

The BMKG predicts that El Nino will last until July, but its strength will be weak, which means that rainfall will still be quite high until April in most parts of Indonesia.

The dry season is predicted to last its normal duration in most regions, but is predicted that the peak from June to August will be drier than last year. “Even though it tends to be dry, it will not be drier than 2015,” Siswanto said. “If El Nino continues after July, this year’s dry season could last longer,” he added. (AIK / E19)