With 47% rain deficit, Kerala stares at drought, IMD data shows
The southwest monsoon, responsible for bringing 80% of the rainfall in the country, made its onset in Kerala on June 8 and its period lasts till September end.
The deficit in the southwest monsoon rainfall in Kerala stood at a staggering 47% on Friday, indicating that the state is on the cusp of a potential drought this year, the data from the Indian Meteorological Department (IMD) stated.
According to the data, Kerala recorded 894.1 mm rainfall against a normal of 1,681.7 mm between June 1 and August 25 this year, a deficit of 47%. The southwest monsoon, responsible for bringing 80% of the rainfall in the country, made its onset in Kerala this year on June 8 and its period lasts till the end of September.
Rajeevan Erikkulam, a meteorologist with the Kerala State Disaster Management Authority (KSDMA), said when the data is collated at the end of August, the month is likely to have recorded the least rainfall ever in the 123-year history of data records of IMD.
“The monsoon came 8 days late in June and the rainfall was impacted by the formation of Cyclone Biparjoy. As a result, we had 60% deficient rainfall in June this year. But in July, we had two spells of rainfall, especially in the northern districts, which cut back the deficit significantly. There were low-pressure areas that formed in the Bay of Bengal and the phenomenon of Madden-Julian oscillation worked in our favour. The westerly winds were strong which brought rainfall,” said Erikkulam.
A look at the rainfall distribution across the country in the same period also confirms that Kerala has the highest deficiency of southwest monsoon rainfall, so far. Manipur in the northeast comes second with 46% deficient rainfall, followed by Jharkhand and Lakshadweep at 34% deficiency.
The absence of rainfall this year is so striking in the state that 13 of the 14 districts of Kerala have recorded ‘deficient rainfall’ ( ranging from -20% to -59%) and one district ‘large deficient’ (ranging from -60% to -99%). While the two least deficient districts are Kannur (-30%) and Kasaragod (-31%) in the Malabar region, Idukki has recorded the maximum deficiency of 63%, so far. Against a normal of 2,108.7 mm rainfall, the hilly district has only seen 783.8 mm rainfall, so far.
The month of August, which had contributed heavily to the seasonal rainfall graph in the last few years, has seen scant rainfall this year in the state. Between August 10 and August 16, Kerala received only 6.5 mm rainfall against a normal of 109.6 mm, a deficit of 94%, the IMD data showed.
The IMD had predicted a ‘normal’ southwest monsoon this year in the state due to the possibility of a positive phase of the Indian Ocean Dipole (IOD), indicating greater-than-average sea surface temperatures and higher precipitation in the western Indian Ocean region, Erikkulam said.
“But in the last two months, the IOD has continued to be in a neutral phase, which led to less rainfall and dry conditions here. But this may change because there is an indication of a positive IOD movement. After the first week of September, there is a possibility of rain in the state. Things are very uncertain right now,” the scientist added.
Indian Ocean Dipole is defined as the difference in sea surface temperature between two areas or two poles.
Madhavan Rajeevan, a former secretary with the Ministry of Earth Sciences, also said that there is hope of rain in September due to favourable weather conditions.
“But the rainfall in September is unlikely to cover the seasonal deficit this year. The departure from normal is almost 50% so it’s unlikely,” he said.
The absence of rainfall in catchment areas has meant that storage levels in some of the state’s biggest reservoirs and dams have plummetted.
As of August 24, according to the data of the Central Water Commission (CWC), the average departure from normal storage in dams in Kerala is -46%. The water levels in Idukki and Kakki reservoirs are down to 31% and 35% respectively. The state of Periyar and Malampuzha dams are also similar, at 32% and 36%, respectively.
The rainfall deficit as well as the cancellation of long-term contracts of Kerala state electricity board (KSEB) with private firms has pushed the power crisis in the state. The Kerala State Electricity Regulatory Commission (KSERC) has for the time being said yes to the request of KSEB for extension of interim arrangement to buy power as per contracts till December 31.
An official of the KSDMA said talks have been ongoing at a higher level regarding the possibility of drought-like situation in the state and the steps to be taken to address concerns of the public, especially farmers.
“The situation is being monitored and directions have been given at the district level to intensify harvesting of rain water,” he said.
