Erratic monsoon pattern likely to cause more damage this season

Kathmandu, June 25: Year after year, many people are killed due to landslides in the hills and floods at plains caused by heavy precipitation during monsoon season (June-September).

With the onset of this year’s monsoon on June 14, already there has been a huge loss of life in the eastern hills. In just 11 days since the onset of monsoon, 13 out of 17 total casualties took place in eastern Nepal alone, and property worth millions of rupees have already been destroyed. Meteorologists and hydrology experts are wandering about the reasons behind so much rains in a short time span in just some particular places.

As of June 23, four persons have been killed in Okhaldhunga’s different landslide incidents, three each in Panchthar and Taplejung’s landslide and flood incidents, two in Sankhuwasabha and one in Bhojpur, according to the National Disaster Risk Reduction Management Authority (NDRRMA).

However, the highest number of 20 missing, out of 26 reported was received from Sankhuwasabha, and three each from Panchthar and Taplejung districts.

Naturally, after the arrival of monsoon from the eastern region, it normally rains at high altitudes of the hills. At that time, special caution is necessary, meteorologists suggested. 

In June, 2021, there was a flash flood in Melamchi River of Sindhupalchowk immediately after the onset of monsoon, causing great damage and loss of lives of dozens of people. 

This time, Sankhuwasabha’s Num region has become the first epicenter this monsoon.  In Num bazar, 387.4 mm of rainfall was measured in 24 hours last Tuesday. That was the third most precipitation event in Num meteorological station.

Usually when the monsoon enters, there is a possibility of heavy rainfall at high altitudes in the initial days. In such a situation, Num region has become a hub of Koshi Province that receives high rainfall in the first week of monsoon. 

“What should be learned from this situation is that when the monsoon starts, there is a need to be careful in Sankhuwasabha, Panchthar, Taplejung districts,” said meteorologist Rambabu Mishra of the Num station.

In this monsoon, Phungling, the district headquarters of Taplejung received the highest rainfall of 71.6 mm. 

Only about 100 mm of rain has been received in Phidim of Panchthar. 

According to Mishra, there is less rain in other districts compared to these three districts. Rain has occurred in all the 14 districts of Koshi province. Rain also occurred in Jhapa. However, not much rain has fallen in Morang, Sunsari’s Terai area and Udayapur. It has been raining a little in all other areas for the past 11 days.

According to the records kept at the Sankhuwasabha’s Num station, 141.6 mm of rain was recorded on June 13, 123 mm on June 16, 111.4 mm on June 18, 135 mm on June 19 and 387.4, the highest rainfall of this season on June 20.

According to Mishra, who is also the technical officer of the Department of Hydrology and Meteorology, Dharan, if it rains more than 50 mm and less than 100 mm, it is considered as ‘heavy rain’. If it rains more than 100 mm it is called ‘very heavy rain’.

Erratic monsoon pattern

Technical officer Mishra said that this year’s monsoon pattern in eastern Nepal is  more isolated than previous monsoons. “In the monsoons before this, it used to rain for months and days regularly and all of a sudden sometimes.” 

“This year’s monsoon is isolated,” he said. “It rained a lot in one place, somewhere it rained heavily within an hour and there was dry spell in other places,” said Mishra. 

This has happened now and will happen again, Mishra claimed. now it seems that we have to work on how to adjust even when such incidents occur, he said.

Indira Kandel, senior divisional meteorologist at the DHM, said that the pattern of monsoon has been seen so unbalanced over the past few years as some regions of the same province receive heavy rain while other region receives very low and no rain even during the monsoon.

Regions which had already received more than normal rainfall during pre-monsoon in the northern and western hills of the country, are more vulnerable to unexpected and instant landslides as the lands there already got wet.    

Awareness, forewarning essential

There was a big flood in Sankhuwasabha’s river this monsoon. A day before the flood, the hydrology section of Dharan had issued a statement alerting the public that the water level in the rivers would increase. 

Secondly, hydropower projects have also been damaged. There are power plants on the banks of the river. In this regard, those who produce hydropower should build it only after studying the banks of the river where the water rises, meteorologist Mishra suggested. 

“We cannot prevent the risk of natural hazards, but we can reduce the human loss,” said Mishra. “We can also protect some physical structures that can be moved.” For this too, advance notice or messaging system should be arranged. 

In Mishra’s experience, western Nepal seems to be a bit more organised than eastern Nepal in terms of organising the information system and early warning system (EWS). “Even in the east, a team should be formed for weather forecasting and possible disaster management at the local level for proper information dissemination,” said Mishra.

There are 40 hydrology measuring stations and 88 weather measuring stations under Dharan-based Meteorological Station. Manual and automatic machines are also kept in such centres. Mishra said that currently 80 per cent of the machines are automatic.

According to Anil Pokharel, Chief Executive Officer of the National Disaster Risk Reduction and Management Authority, there is a long period of torrential and heavy rain (cloudburst) after floods and landslides, causing huge human losses in eastern hilly districts.

“It was raining in Panchthar and Taplejung from Thursday and Friday,” said Pokharel. “The ground was very wet.” Even on Saturday night, when there was heavy rain, there was a flood causing great damage.

 In last year’s monsoon, 74 persons died due to monsoon-induced disasters mainly by floods, landslides and heavy rains. Of them, 15 were killed due to floods, 54 were killed in landslides and five due to heavy rains.  

Below-normal rain forecast but causing huge losses  

The Department of Hydrology and Meteorology has predicted that most places in the country will receive less than average rainfall in this year’s monsoon. But in less than 12 days of the monsoon, nearly two dozen people had died due to heavy rains in the eastern hilly districts. At least 26 people are still missing and 43 houses were completely damaged and 117 partially damaged, according to NDRRMA update as of June 23.

About 80 per cent of the total rainfall in Nepal is believed to occur in the monsoon, four months starting from June to September.  Therefore, preparations are made to reduce disaster by targeting monsoon. But this year, as the monsoon has just been in activating stage from June 23, the details of the huge damages and loss of lives have started coming out, said Climate Change expert Binod Pokharel.

“Even a few extreme precipitation events are causing major floods and landslides during the monsoon taking lives of many people in a short span of time, which is mainly due to fragile geography of Nepal where people stay in weak geography despite knowing that they are at risk,” said Pokharel.

Monsoon to affect 1.25 million citizens 

Anil Pokharel, the executive head of the NDRRMA, said after collection of all the data from all the provinces and ward levels, the Authority has estimated that 1.25 million people of 286,998 households are likely to get affected by this year’s monsoon and informed about the additional preparations made by the authority for monsoon disasters. The project came by the National Action Plan, Monsoon Preparedness and Response Action Plan 2023 approved by the Home Minister, chairman of the executive committee of the NDRRMA. According to the projection of the Monsoon Action Plan 2023, the highest number of people and households to get affected from this monsoon is in Madhes Province with 403,180 people of 92,261 households followed by Koshi Province with 301,143 people of 68,911 households. After that, Lubmini Province’s 199,862 people of 45,735 households may be affected by the monsoon. 

In Sudurpaschim, it has been projected that 147,060 people of 33,652 households may be affected from the landslides and floods this season.  

Pokharel said that smart sirens at 34 locations in different most vulnerable places of the country have been installed, and procedure to purchase emergency mass rescue vehicles and ‘A Class’ ambulances for advance notification and advance operations, and arrangements have been made to stay one each in all the seven provinces and Kathmandu Valley.

So far, 100,422 people have been registered in the volunteer system for the monsoon and other rescue operation related to disaster, said CEO Pokharel.

Districts to be affected

CEO Pokharel said that the districts that are at high risk of landslides due to monsoon are Ilam, Panchthar, Dhankuta, Tehrathum, Okhaldhunga, Lalitpar, Nuwakot, Dhading, Tanahun, Syangja, Palpa, Gulmi, Arghakhanchi, Baglung, Pyuthan, Rolpa, Rukum West, Dailekh, Achham and Baitadi.

Similarly, the districts to be affected by frequent floods include Jhapa, Morang, Sunsari, Saptari, Siraha, Dhansha, Mahottari, Sarlahi, Rautahat, Bara, Parsa, Chitwan, Nawalpur, Parasi, Rupandehi, Kapilvastu, Dang, Banke, Bardiya, Surkhet, Kailali and Kanchanpur.