Monsoon is the lifeline for approximately 88 crore people living in India who are dependent on farming. Both excess and deficient rainfall take a toll on the farmer's yield.
As per the final long-range forecast issued by the government's official weather prediction agency, Indian Meteorological Department, this year "seasonal rainfall over the country as a whole was expected to be 98 percent of its long period average (LPA) in 2017. In actual, the year ended with an all India average rainfall of 95 percent of its LPA — a deficiency of 5 percent. The year 2016 also had a monsoon rainfall deficiency of 3 percent, though within normal limits. It is significant to note that both the years 2016 and 2017 ended with All India Summer Monsoon Rainfall on the negative side of the LPA after two consecutive monsoon deficient years 2014 and 2015,” says Dr Kanti Prasad, consultant at Weather Risk Management Services, weather scientist and former deputy director general of India Meteorological Department.
Weather Risk Management Services (WRMS) is a private sector organisation which provide weather and climate services (like IMD) to help farmers plan their farming activities during various cropping seasons.
In the monthly rainfall scenario during 2017, the country had normal monsoon during the months of June and July with All India average rainfall of +4 percent in June and +2 percent in July. However, the months of August and September turned out to be deficient with rainfall departures as -13 percent and -12 percent respectively due to prolonged break monsoon conditions. The corresponding figures in 2016 were -11 percent for June (due to delayed onset), +7 percent for July, -9 percent for August, and -3 percent for September.
In the spatial rainfall distribution during the monsoon season in 2016, the rainfall was fairly well distributed over the country except for a few isolated pockets of deficient rainfall, whereas rainfall distribution in 2017 shows a continuous belt of deficient rainfall extending from Punjab, Haryana, Uttar Pradesh to East Madhya Pradesh and Vidarbha.
In 2016, out of 36 meteorological subdivisions, seasonal rainfall was normal in 23 subdivisions (72 percent of total area of India) and was excess in four subdivisions (13 percent of total area). It was deficient in the remaining nine subdivisions. In 2017, out of 36 meteorological subdivisions, seasonal rainfall was excess in five subdivisions, normal in 25 and deficient in six subdivisions.
In 2016, withdrawal of monsoon commenced from West Rajasthan on 15 September (with a delay of two weeks) and withdrew completely from the entire country on 28 October. During 2017 withdrawal of monsoon was significantly delayed. It commenced from West Rajasthan towards the end of September on 27. The delay in withdrawal happened due to cyclonic activity over northwest India during the third week of September this year.
According to a study carried out by the Stanford Woods Institute for the Environment, there will be changes in the atmosphere like winds and moisture which are likely to be responsible for changes in wet and dry spells in the upcoming years. After studying trends of monsoon rains of around 60 years, the researchers have warned of extreme weather conditions in future.
The phenomena of increased intensity of rains in future can be attributed to global warming and India is not the only country affected by it. In fact, every country including the United States and Europe are witnessing such abnormal rains. It is said that the intensified rains will be the order of the day and people have to deal with such heavy rains with better urban management techniques. Research suggests that the rainy days will come down in future but the quantum of rain might not go down drastically due to heavy downpours. Technology is available these days, to predict such rains over a region but not finding out specific places receiving such downpours.
The author is a consultant at Weather Risk Management Services and former Deputy Director General India Meteorological Department.
Updated Date: Oct 08, 2017 16:13:42 IST