Climate & Environment
Rainfall brings some respite from pollution but threat of more wildfires remains
With the rain, the number of wildfires came down to 59, air quality index to 42 from a high of 334, and visibility went up to 7,000 metres from 1,000 metres.Chandan Kumar Mandal
The brief rainfall of Wednesday evening brought a temporary but much-needed respite from the hazardous levels of air pollution and extreme wildfires in different parts of the country.
Wednesday’s rainfall resulted in clearing the haze which had blanketed Kathmandu Valley and other hilly areas on Thursday and thus improving visibility.
“The weather has significantly improved in comparison to the past few days. Last Friday, visibility had reduced to only 1,000 metres. Now, it is 7,000 metres,” said Raju Pradhanang, a senior meteorologist with the Meteorological Forecasting Division. “Dust particles in the atmosphere have settled down with the rain on Wednesday. At around 2:30pm on Wednesday, visibility was around 3,000m as pollutants had come down.”
Starting last week, particularly Friday, Kathmandu Valley and many other cities had been shrouded in toxic smoke due to intense forest fires, leaving the general public gasping for clean air.
On Thursday afternoon, air quality of Kathmandu Valley and other parts of the country significantly improved.
The Air Quality Index (AQI) of Kathmandu, which had been hovering between ‘very unhealthy’ and ‘hazardous’ categories for several days, improved significantly on Thursday. At 2:45 pm AQI level was 84, down from 334 on Saturday. At 4:45pm, it came down to 42, which means the air is of ‘good’ quality.
Air pollution level also got better in Pokhara, Patan, Siddharthanagar and Dhankuta even as AQI levels still remained ‘unhealthy for sensitive groups’. In Nepalgunj and Tulsipur, it was of ‘moderate’ level.
According to Pradhanang, the drastic improvement in air quality was because of the light to moderate rainfall in several places.
As per the weather office record, Pokhara received 20.4 mm rainfall and Kathmandu witnessed 9.8mm rainfall on Wednesday evening.
The brief precipitation also came as a saviour for controlling wildfires which this season have been responsible for the deteriorated air quality by sending up hazardous smoke.
“Precipitation was necessary for controlling the wildfires and then clearing up smoke and haze,” said Sundar Prasad Sharma, an under-secretary who serves as forest fire expert at the National Disaster Risk Reduction and Management Authority. “The rainfall has come as a relief.”
Despite being just a brief drizzle, it significantly helped in controlling wildfires as was evident in the drop in the number of wildfire incidents reported across the country.
As per the Forest Fire Detection and Monitoring System in Nepal, a government database for tracking wildfire incidents, a total of 130 wildfire incidents were reported in 29 districts on Wednesday. They came down to 59 forest fires in 18 districts on Thursday afternoon, with the highest in Doti with 11, followed by Salyan with eight and Surkhet with six.
But the threat of more wildfires remains.
“Rain definitely provided relief. But if there isn’t any rain for the next three or four days, the forest fire situation can go back to as it was a few days ago,” said Sharma. “Despite the momentary relief due to the rain, we cannot sit with our hands tied and be complacent. Forest fire incidents can once again increase as the fire season is not over yet.”
This forest fire season, which begins in November and lasts till April, has been the most disastrous in terms of the number of wildfire outbreaks. According to the National Disaster Risk Reduction and Management Authority, a total of 2,713 wildfire incidents in a record 73 districts have been reported between November and March this year.
The country is witnessing four times more wildfire incidents this year than the average of the last five years, according to Sharma.
“In the past, around 2,500 forest fire outbreaks would be recorded in the whole season, whereas nearly 500 forest fire events have been recorded in a day,” said Sharma. “Community forest groups and Division Forest Offices have been fighting wildfires with whatever resources they have. They cannot douse big fires, but they have been trying. They face a lack of resources, equipment and a trained human resource.”
What further worries officials is the uncertainty over continued rainfall during the ongoing wildfire season and the concomitant pollution it causes.
The pollution level may have improved but the air has not cleared up yet.
“Although pollutants have been largely washed out, it’s not completely clear,” said Pradhanang, the senior meteorologist. “Kathmandu still has haze as rainfall was neither heavy nor even across the Valley.”
The arrival of another wave of wildfires is also likely because there is a slim chance of rainfall across the country in the coming days.
As per the forecast, brief rainfall will occur at one or two places in the hills, including Kathmandu Valley, from Gandaki Province to Province 1 over the next few days, according to Pradhanang.
“If wildfires are not doused, then the pollution level and haze will soar back once again,” said Pradhanang.
Sharma also fears that without rainfall wildfires across the country could intensify. According to his analysis, nearly 60 percent of all forest fire incidents take place in April and its fourth week is considered the peak season for wildfires.
“The rain was helpful and everyone became happy. But we cannot be satisfied and sit back. Even a couple of days of doing nothing can result in similar devastation. Everyone needs to be alert,” said Sharma.
“Without enough rainfall, forest fires will return once again. Rains at least once or twice a week can control wildfires. If not, forests will continue to burn.”