Monsoon 2021: Why we should worry about deficit rainfall in July
New Delhi, Aug 02: After its vigorous revival in the first week of July that saw floods, cloudburst and landslides in several parts of the country, the Southwest Monsoon 2021 ended with a seven per cent deficit for the month, the India Meteorological Department (IMD) said on Sunday.
7% deficit rainfall in July
The rainfall in July was minus seven per cent which comes to around 93 per cent of the Long Period Average (LPA), IMD Director General Mrutunjay Mohapatra said.
Rainfall in the range of 96-104 is normal whereas precipitation in the range of 90-96 is classified as below normal. July recorded extremely heavy rainfall over coastal and central Maharashtra, Goa, Karnataka.
Several towns and cities in Maharashtra were deluged to very heavy rainfall which resulted in catastrophic events like landslides claiming scores of lives and damaging property. The north Indian states -- Jammu and Kashmir, Uttarakhand, Himachal Pradesh and Ladakh -- also saw cloudburst events that claimed several lives.
The national capital too recorded a very good rainfall activity. But overall, the rainfall recorded for the month was seven per cent less.
The IMD had predicted normal rainfall in July. "We had predicted normal rainfall for July which was somewhere around 96 per cent of the LPA. July brings maximum rain over the country, but there was no rainfall activity over north India until July 8 which could have been the reason behind the deficit," Mohapatra said.
The Southwest Monsoon arrived over Kerala on June 3, two days after its normal schedule. But it very rapidly covered the east, west, south and parts of north India by June 19. But after that it entered into a phase that witnessed a spell of no rainfall activity. It started reviving from July 8.
The Southwest Monsoon reached Delhi on July 13 after a delay of 16 days and covered the entire country the same day. June received 10 per cent more rainfall than normal. Of the four-month rainfall season, July and August receive the maximum precipitation. Overall, the country has received one per cent less rainfall than normal from June 1 to July 31. The deficit was minus 13 per cent in the east and northeast subdivision of the IMD.
Northwest India division which covers north India recorded a two per cent deficit. The south peninsula division which covers the southern states received 17 per cent more rainfall while the central India division that comprises west and central India recorded one per cent more rainfall than the normal.
Rainfall deficit a worry
July is typically the most important of the monsoon season because the most rainfall occurs across the country during this time, and it is when the rainfall really takes hold across all of the Indian subcontinent.
For those who track India's drought history and the agricultural cycle, deficit rain in July is always a cause for great worry.
The spatial distribution of monsoon rain dictates our cropping cycle.
In July, farmers transplant crops, particularly paddy. Paddy needs regular showers during this phase. Though the stalling of the monsoon for the three weeks till July 11 adversely impacted sowing, there has been a pick-up of the activities over the past week, especially in major crop-producing regions.
History shows that deficit rainfall in July triggers droughts. An analysis of the country's six worst droughts during 1877-2005 shows that deficit rainfall in July was a common factor. It is very unlikely that the remaining months can make up for such a deficit.