Climate & Environment
Country received only 25 percent of normal rainfall this winter
Dry spell, which began after the monsoon, continues as Nepal heads to pre-monsoon.Chandan Kumar Mandal
Nepal witnessed a significant drought this winter with the total rainfall falling short by 75 percent of the normal average for the season.
The scant winter rainfall figures come after an equally dry post-monsoon (October-November) period in which the country received only 25.6 percent of the average rainfall for the season
“The amount of rainfall the country received this winter is very less compared to our average for the season,” said Indira Kadel, a senior meteorologist at the department.”
According to official figures, during the three winter months (December-February), Nepal would, on average, receive 60.4mm rainfall. But this season, it only received 15.4mm.
In Nepal, the average rainfall figure for any place for any particular month and season is calculated as the average of the total rainfall received during a specific month or season between 1981 and 2010.
The figures show that the country is going through a severe drought-like situation, said Kadel, also the chief of the Climate Analysis Section of the department.
“Some places like Bhairahawa did not receive rainfall at all. Data recorded at 20 major stations of the department tell the same story,” said Kadel.
The rainfall figures recorded this season have been in line with the Winter Climate Outlook of the Department of Hydrology and Meteorology for this winter (December 2020-February 2021). In December, the department had forecasted that winter would be “hot and dry”.
An area is said to have received “normal” rainfall if it receives rain equivalent to 90 to 110 percent of the average rainfall. If the figure falls below 90 percent, the area is said to have received “below-normal” rainfall. Figures above 110 percent are deemed “above-normal” rainfall.
A long period of drought could impact the country in several ways, especially when normal rainfall was recorded during the monsoon, officials say. “The post-monsoon season was dry and then winter is also dry. Such a shortage of rain can result in drying up of springs, and trigger scarcity of water and fire incidents,” said Kadel. “Even available water could evaporate faster during hot weather.”
Winter rainfall brought into Nepal by westerly disturbances contributes nearly 3.5 percent to the country’s annual rainfall. Despite its comparatively low contribution, winter precipitation is considered valuable for crops, especially in high mountains where snow provides much-needed moisture for a longer period of time.
Last winter, the country had received above-normal rainfall in most places. This year, however, the Far-western region experienced light rainfall during the first week of January and the second spell of rain came only in the first week of February.
“Winter rainfall is more important than post-monsoon precipitation. Post-monsoon precipitation merely marks a transition to the monsoon,” said Kadel adding that the country now needs to be wary of forest fires in the pre-monsoon period.