Climate & Environment
Forecasts for smaller areas could minimise damage and save lives, experts say
Forecasts for larger areas don’t help communities prepare much. With more resources for technology and research, predictions can be more specific, meteorologists suggest.Chandan Kumar Mandal
This year the monsoon arrived with a bang.
In the first week of its onset, heavy rainfall unleashed floods and landslides in different parts of the country, mainly the hill and mountain districts.
As in the past few years, Sindhupalchok was the worst hit. Flooding of the Melamchi river displaced hundreds of families, killed five and 20 went missing. Manang, usually a dry district, saw unprecedented floods and landslides sweeping away houses and hundreds had to be airlifted to safety. Lamjung also witnessed damage to private and public property and displacement of families.
With three months of the monsoon still remaining and the further devastation it could cause, experts and authorities have called for improving early warning systems to minimise the loss of lives and property.
“Preparations for the rest of the monsoon season should start with the weather office providing more localised weather updates rather than simply sharing forecasts on larger territories like provinces and regions as it is doing now,” Madhukar Upadhya, a watershed practitioner and climate change expert, said.
At present weather updates come for Gandaki or Lumbini province and do not say anything much about small valleys like Melamchi.
“The Department of Meteorology and Hydrology should provide more details and pinpoint information on rainfall so that local units and district authorities can warn communities,” he told the Post.
The Meteorological Forecasting Division under the Department of Meteorology and Hydrology normally provides weather updates twice a day—at 6am and 6pm. The Daily Weather Forecast Bulletin provides meteorological analysis, present weather status and prediction for the next three days. If there is a sudden change in weather condition, the met office also issues a special bulletin.
However, all these weather updates broadly share information on weather conditions in extensive geography like regions—eastern, central or western—or province-wise as in recent years.
“When rainfall prediction is given for one province, chances are one district of the same province could be battered by heavy rain whereas another district on the other end of the province could not be receiving the same intensity of rainfall,” said Upadhya.
Making more specific projections may not be too difficult, according to him.
“We can also rely on historical data to identify areas that have received more rainfall than others and provide localised weather updates,” Upadhya said. “Besides, if the monsoon trough is positioned in one area, we can predict where it could possibly rain and alert the authorities and communities.”
The Department of Meteorology and Hydrology admits that it has not been able to give weather updates for smaller areas and said this is because it does not have the technical capability to do so.
“We are trying to provide district-specific weather forecasts but have not been able to do so, so far. Earlier, the weather updates would be only for regions, which have come down to provinces now,” said Saraju Kumar Baidya, director general of the Department of Hydrology and Meteorology, referring to the five development regions that the country was divided into before the federal structure was adopted in 2015. “But in case of flood warnings we even provide district-wise updates.”
Despite the fact that there is room to improve on forecasts, in recent years, the department has done a remarkable job in terms of flood early warning systems and alerting the general public living in nearby rivers across the country, according to experts.
The Flood Forecasting Division of the department monitors the water levels in several river basins through 89 stations to provide 24-hour updates on water flow in those rivers. Based on these and rainfall prediction authorities warn communities of imminent floods.
There are also 215 rainfall monitoring stations across the country and data from them helps in flood warnings for downstream communities.
“For rivers where there is no flood monitoring system, we give general warning based on rainfall forecast for the area,” said Baidya.
During the monsoon season, the Flood Forecasting Division also publishes a daily Flood Forecasting Bulletin at 7am, mentioning possibilities of floods in major rivers of the country.
But looking at the changing rainfall patterns in recent years, there is a need for more enhanced weather predictions and the possibility now of a three-day weather forecast with upgraded equipment means that it can be done, according to Upadhya.
“Nearly 10 years ago even flood forecasting was not imagined. But starting at the small-scale level initiatives, flood-forecasting warning has been really significant in informing communities. A similar early warning system is required for rainfall as well," he said.
Lately concentrated rain has been occurring in small patches or river basins more frequently, probably because of climate change, causing destruction to downstream communities.
“According to Upadhya meteorology authorities need to provide basin-wise rainfall prediction and narrow it down to other small rivers.
Government authorities agree that more needs to be done beyond regular weather forecast dissemination.
“We need impact-based forecasting for various disasters,” said Anil Pokharel, chief executive officer with the National Disaster Risk Reduction and Management Authority under the Ministry of Home Affairs. “If there are possibilities of extreme weather events then the weather office should communicate impacts of landslides and lightning so that communities can remain alert and move to safer places rather than just weather observations as is the case now. This level of forecast or communicating risk has not happened so far.”
However, the Met office says it is easier said than done.
Providing more area-specific daily weather updates abounds with challenges for several reasons, according to Baidya.
“Any weather phenomenon covers a large area, so it makes it difficult to say that it will rain at this particular place at this particular time. Also since Nepal is a mountainous country rainfall pattern is varied even within small geographical areas. For instance, it may be raining in one area of Kathmandu Valley but not in another one,” said Baidya. “Finally we do not have the required technology for area-specific forecasts because of insufficient resources.”
According to him, the weather forecast models at the disposal of his department cannot make such small-scale weather forecasts.
Meteorologists rely on forecasting models which are computer programmes that provide meteorological information to predict the weather based on wind speed, direction, air temperature, moisture, and pressure collected from different locations.
“Besides, all the models have some levels of uncertainty. On top of that, our topography and rainfall variation makes area specific forecasts even more challenging,” said Baidya. “Using existing computer-based global forecast models, we need to customise them for Nepal with Nepal’s topography, weather systems, input of Nepali weather data and make the required changes.”
Fine-tuning forecast models requires extensive research and research has never been a forte of Nepal’s government, he said.
Besides, this means more resources.
For experts like Upadhya, resources should not be a concern as this is a matter of people’s lives and property.
Instead of building bridges and roads, investing in the technology required that could save and improve lives should be prioritised, he said.
The government’s monsoon action plan has estimated that nearly 1.8 million people are likely to be affected by monsoon-related disasters this season.
“The estimation that 1.8 million to be affected should also include how each of those individuals will be impacted by the monsoon rains. Otherwise, that’s just a vague number,” Upadhya said. “Such data looks good for discussions among government agencies like the National Planning Commission, but does not make sense in the everyday lives of the people.”
The importance of preparedness cannot be overemphasised.
“Rather than spending billions in the aftermath of disasters that damages infrastructures and livelihoods and kills people, some millions invested in developing early-warning systems could make lots of difference and save lives,” said Baidya.
But Baidya and his department alone cannot make such priorities.
“We have been reaching out to the government for the required human resources and budget for improving our capacity,” said Baidya. “The department is a science-based entity, and as long as we do not devote enough resources for research, the weather forecast, flood forecast and climate forecast cannot be accurate. With the availability of more resources we can provide more localised and more accurate weather forecasts.”