Regions in at least 11 southern Indonesian provinces, some of which have gone more than seven months without rain, are expected to see the prolonged dry spell continue until December amid the worst dry season the country has experienced since 2015.
Indonesia’s Meteorology, Climatology and Geophysics Agency (BMKG) on Saturday said that cities and regencies across Lampung, Banten, West and East Java, Yogyakarta, Bali, West and East Nusa Tenggara, as well as South and Southeast Sulawesi, had not seen rain for more than 61 days straight.
Buleleng in Bali and Sampang in East Java have not seen rain for more than 216 days, while East Sumba in East Nusa Tenggara (NTT) has suffered the longest at 249 days.
BKMG has raised the drought alert for the regions to its highest level, saying the chance of affected-areas receiving low-intense rainfall by December 23 was 70 per cent.
BMKG’s climate variability analysis head Indra Gustari said: “There are two factors: First is the weak El Nino phenomenon that we observed from the middle of last year until July this year. However, a more dominant factor is the relatively low sea surface temperature, a global phenomenon known as the positive Indian Ocean Dipole (IOD).”
IOD, Indra said, was similar to El Nino but it occurred in the Indian Ocean instead of in the Pacific Ocean. It has three phases; neutral, positive and negative.
A positive IOD, which is currently being observed, means that part’s of Indonesia’s territorial waters in the eastern Indian Ocean is cooler, while the western waters near Africa are warmer.
This phase tends to cause droughts in Indonesia, as the low sea surface temperature slows down seawater evaporation and cloud formation, resulting in less rainfall. The positive IOD also slowed down the Asian monsoon, which greatly affects rainfall intensity in the country, according to Indra.
“Climate change is believed to contribute to strengthening the intensity [of the phenomenon] as the average global temperature keeps rising,” Indra told the Jakarta Post.
A 2013 report by the Intergovernmental Panel on Climate Change (IPCC) revealed that the ocean had absorbed more than 93 per cent of the excess heat from greenhouse gas emissions since the 1970s, causing ocean temperatures to rise.
The International Union for Conservation of Nature (IUCN) said ocean warming caused more extreme weather events.
The BMKG estimated that in 74 per cent of season zones in the country, the rainy season would start later than the 30-year average calculated between 1981 and 2010.
Southern Indonesia’s rainfall is expected to peak in January or February, with Indra warning of floods in the area around that time, as well as in December for the northern part of Sumatra and most of Kalimantan.
The National Disaster Mitigation Agency (BNPB) recorded at least 256 villages across NTT, Central and West Java as well as Bali experiencing drought as of Friday.
In a statement released on Friday, BNPB spokesperson Agus Wibowo said local administrations had been distributing water to their residents using their regional budget, adding that the agency would provide emergency funds if necessary.
Agus said North Central Timor regency in NTT had requested nearly $45,000 of emergency funds and Alor regency in NTT had asked for more than $65,000.
According to local agencies, the two regencies had 99 villages and 60 villages, respectively, suffering from drought, but the North Central Timor administration could only spend more than $7,000 to distribute water to 20 villages.
“We recommend that the regional administrations plant trees in critical areas and in rainwater-storing areas,” Agus said.
THE JAKARTA POST/ANN