Regional haze eases for the moment as rain brings relief to Indonesia’s Sumatra, Kalimantan

(CNA) – The number of hotspots in Indonesia has dropped by more than 40 per cent after rain in parts of Sumatra and Kalimantan, as the overall haze situation eased throughout the region on Wednesday (Sep 25).

The number of hotspots stood at 1,744 on Wednesday, down from 3,150 two days ago, said Mr Agus Wibowo, who heads the Centre for Data, Information and Public Relations in Indonesia’s National Board for Disaster Management.

He noted in a statement that there was rain on Tuesday night in the provinces of Riau, Jambi, South Sumatra, West Kalimantan, Central Kalimantan and South Kalimantan.

Meanwhile, the Indonesian police and the Ministry of the Environment and Forestry said 323 people have been arrested on suspicion of being involved in setting forest fires.

Mr Dedi Prasetyo, the chief of the Police Public Information Bureau, said 14 plantation companies are also suspected to have been involved in these fires.

Since January, more than 300,000 ha of forests and plantations have been destroyed by fires in several provinces of Indonesia.

The peatland fires have also caused haze that blanketed Malaysia and Singapore since early September, having been blown there by the Southwest Monsoon winds.

The Riau provincial government declared an emergency this week after the air quality deteriorated to the hazardous level, with the Air Pollutant Index (API) exceeding 500.

An API of zero to 50 indicates good air quality; 51 to 100, moderate; 101 to 200, unhealthy, 201 to 300, very unhealthy and 300 and above, hazardous.

In Malaysia, the meteorological department had earlier predicted the haze situation would improve following the Inter Monsoon phase beginning Tuesday.

All areas in Malaysia recorded API in the good or moderate range on Wednesday, with the exception of Johan Setia, Selangor.

The API reading taken at 4pm for Johan Setia was 144, which is considered unhealthy.

Over in Singapore, showers on Wednesday alleviated hazy conditions, as the air quality improved markedly.

Pollutant Standards Index (PSI) readings have been in the moderate range since Tuesday night, falling to between 62 and 67 at about 4pm.

PSI readings of 50 and below denote “good” air quality, “moderate” for 51-100 and “unhealthy” for 101-200.

The National Environment Agency noted earlier this week that although showers may have helped to improve the haze situation, the hotspot activities in Sumatra can be expected to persist.

“Singapore may still experience occasional slightly hazy conditions over the next few days if the prevailing winds blow in smoke haze from Sumatra,” it said.