Why we should worry about 8% deficit rainfall in July

Historically, a deficit monsoon in July invariably leads to drought

By Richard Mahapatra
Published: Wednesday 01 July 2015

There is some perceived good news about the monsoon as it completes one quarter of its four-month season. The country has received 24 per cent above average rainfall for this month. Though it arrived five days late, it covered the entire country in less than two weeks.

Heavy showers and rising prices have prompted farmers to increase planting of pulses by 80 per cent compared to last year, while oilseed planting has jumped fivefold from 2014, latest data from the agriculture ministry shows.

The stock market made some gains on the back of this trend and the fears of a deficit monsoon almost fizzled out of people’s minds.

But by the last week of June, the India Meteorological Department (IMD) flagged off a warning. It forecast eight and 10 per cent deficit in July and August respectively with an error margin of 9 per cent either way. 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, the country witnesses the peak of the monsoon. One-third of total monsoon rains are received in this month—the highest in the four-month season.

June accounts for just 18 per cent of rain. The next big share of rain is received in August, around 29 per cent.

Also, in July, farmers transplant crops, particularly paddy. Paddy needs regular showers during this phase. While surplus rains in June have resulted in a surge in sowing, farmers stare at imminent damage to crops if it doesn’t rain regularly in July.
Euphoria over the rain bounty in June led everyone to ignore an important fact. While 58 per cent of districts received surplus rain, the remaining 256 districts (of a total of 608) are still witnessing deficit or scanty rainfall. These are tentatively the same areas that suffered heavy crop damages due to a deficient monsoon in 2014 and unseasonal rains from January to April this year. The rainfall deficit in these districts ranges from 15 to 73 per cent.

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 (see table). It is very unlikely that the remaining months can make up for such a deficit.

Analysis of six big droughts from 1877 to 2005
Feature 2002 1987 1972 1918 1899 1877
Rainfall deficiency (% deviation from normal) -19 -19 -23.5 -23.9 -26.8 -29.1
Area under deficit rainfall (% area) 56 64 49 68 83 67
Deficiency of rainfall in July (% from normal) -49 -29 -31 -48 -32 -43
Source: Natural and Anthropogenic Disasters: Vulnerability, Preparedness and Mitigation edited by M K Jha

Scientific studies confirm that July plays a critical role in the overall performance of the monsoon. In 2013, scientists from the Indian Institute of Tropical Meteorology studied the overall monsoon outcome when rainfall in June, July, and in both months was above or below normal, using data going back as far as 1871. They found that with deficit rainfall in June, the chances of a deficit overall monsoon were around 77 per cent. But if July experienced a deficit monsoon, the chances of a deficient monsoon rose to over 90 per cent.

Let’s look at two of the country’s worst droughts. The year 1987 saw a rainfall deficit of 26 per cent by the end of July and an 18-per cent below normal monsoon. In 1972, the July rainfall deficit was about 30 per cent and the overall monsoon ended at 25 per cent below average.

The agriculture ministry has already launched a contingency plan to avert a drought-like situation. But with the surge in sowing, there is a high possibility of a further worsening of India’s agrarian crisis.

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