Sunday, May 25, 2014

Monsoon: Vidarbha based environmentalist predicts erratic rains on the basis of ant colonies!!!

(TimesofIndia) Southwest monsoon already reached Andaman and Nicobar Islands on Sunday and is expected to reach the southern coast of Kerala around June 5. The arrival of monsoon in the region is normally ten to 12 days after reaching Kerala, according to Indian Meteorological Department (IMD). Thus it could be arriving in Central India around June 15. However, an expert whose forecasts are made by observing the nests of weaver ants says the monsoon will arrive in the city between June 9 and 13.

The weather department has predicted a delayed onset of monsoon from what IMD sees the normal date, June 1. Fearing possible occurrence of a warm ocean current El Nino, IMD has also said that the rainfall this year could be below average. However, environmentalist and chemist Surjyoti Bagchi makes his predictions based on the shapes, sizes, number and position of nests built by weaver ants. His past predictions have been very close to the mark.
"Based on the behaviour of the ants at Koradi Thermal Power Station, my prediction for monsoon in Nagpur district for the current year is that the arrival would be normal rather than late. This year, I saw the formation of large, oblong-shaped nests only in the upper portion of most of the trees. Some trees also have nests at the lower side of the trunks, which are not a common occurrence but had also happened in 2009,"
informed Bagchi. The number of nests, though, is fewer than usual, he added. Interpreting these observations, Bagchi predicted the rainfall this year would be erratic.
"Some areas of Vidarbha would be going dry while others would be receiving very good rains, just like it happened in 2009. Nagpur district is not likely to experience drought, though," he said.
Like Bagchi's predictions, even IMD's forecast links this year's monsoon to that of 2009. El Nino, which occurs periodically, results in changing of wind directions and weather patterns. The drought and low rainfall in 2009, 2004 and 2002 are attributed to this phenomenon. Accordingly, IMD has predicted a below average rainfall this year.

Bagchi said the scenario would not be as bad for Nagpur district that would receive something between 800 to 900mm rainfall. The normal rainfall for Nagpur is 976 mm.


Monsoon would touch Nagpur between June 9 and June 13. Average rainfall for Nagpur district would be around 800mm-900mm.

Monsoon should take a vigorous start. There is a strong possibility of erratic distribution in the region thereafter.


Around three weeks before arrival of rains, weaver ants start building their colonies. Depending on the shape, size and height of these nests built on tree trunks, Bagchi makes predictions about the rainy season. He shared with TOI some key pointers for doing this.

Round and short nests built at low level on the trees and smaller number of nests indicates less rains. Many oblong-shaped nests at higher levels indicate good to heavy rains.

The direction in which these nests are built are opposite of the direction of the winds that cause monsoon. For example, when south-west monsoon winds bring rains, the nests face north-east direction.

Number of nests can be directly related to the amount of rainfall


All nests this year are oblong-shaped, with most being on top of the trees. However, their number is slightly low.


In 2009, when Bagchi observed small and big nests at both high and low levels, he predicted erratic rains and was proved right as Chandrapur faced a drought that year while Nagpur had normal rains. In 2011, he predicted normal monsoon which was how it happened.

For 2013, Bagchi had said rains would arrive in the third week of June and they arrived on June 12. His prediction of above average rainfall also came true

No comments:

Post a Comment