Bengaluru, DHNS: 20 districts record temperature of more than 40 degree Celsius. The sizzling temperatures this March have brought into sharp focus the prevailing drought situation in the State, considered the most severe in the last four decades.

The severity has been attributed to the failure of both the south-west (SW) monsoon (between June 1 and September 30) and the north-east (NE)?monsoon (between October 1 and December 31).

The general pattern has been that if the SW?monsoon fails or is below normal, the NE?monsoon has come to the rescue with above average rainfall. However, on three occasions - 1972, 1985 and 2003 - during the last four decades both the SW?and NE?monsoons have failed in the same year. Now, the year 2015 also finds a place in this list.

According to statistics maintained by the Revenue department, the magnitude of deficiency of rainfall due to the failure of SW?and NE?monsoon in 2015 is the highest compared to the previous occasions, making it the most severe in the last 44 years. In 2015, the deficiency stood at 54%, it was 22% in 2003, 28 % in 1985 and 37 %in 1972.
In 2015, the State received only 22% SW monsoon rains.

There was some optimism as the NE monsoon entered the State, but it too failed, particularly in north interior Karnataka comprising the districts of Ballari, Koppal, Raichur, Kalaburagi, Yadgir, Bidar, Belagavi, Bagalkot, Vijayapura, Gadag, Haveri and Dharwad. It was a double whammy for the people of these districts as they were yet to come out of the minor drought of the year 2014.

“It is due to the El Nino effect. The effect has been at a historic high this year. A powerful El Nino effect results in extreme weather conditions in different parts of the world. While some parts could face severe drought, other parts could receive heavy above average rainfall,” explains G?S?Srinivasa Reddy, Director, Karnataka State Natural Disaster Monitoring Centre (KSNDMC).

Simply put, El Nino phenomenon is a climatic cycle that depends on the surface temperature of the Pacific Ocean with a global impact on weather patterns. It is just not Karnataka, but neighbouring Maharashtra, Telangana and Andhra Pradesh are also under stress due to the El Nino effect.

Not much rain can be expected in the coming months as the period between January and May accounts for only 12% of the annual rainfall in the State, Reddy said.

He said it could be a worrying factor if the effect continues into May, once again affecting the SW?monsoon. However, there are indications that the effect could weaken in the coming months.

The high temperatures across the State could further deplete the already low reservoir levels, Reddy pointed out. As many as 20 of the 30 districts in the State have been recording temperatures of above 40 degrees Celsius in the last few days.

The total storage capacity in major reservoirs stands at 860 tmc ft?of which the present level stands at 213 tmc ft. If the present weather conditions continue, reservoirs could lose 30 tmc ft?to evaporation, Reddy said.

“There is a certain loss of water in reservoirs due to evaporation. It is usually 5 mm per day. However, at above normal temperature it could be 6 to 7 mm per day,” Reddy said. A back of the envelope calculation puts the evaporation loss figures at 30 tmc ft.

Photo credit: DHNS