Seasonal showers declined 6% from the long-period average up to August 6
For the first time since the current monsoon season started in June, the country’s water storage has dropped from both the level a year before and the normal benchmark average, thanks to a slowdown in monsoon rains since early July.
Seasonal showers declined 6% from the long-period average (LPA) up to August 6, worsening from a deficit of 4% witnessed until July 30.
According to the data compiled by the ministry of water resources, the storage across 91 water reservoirs touched 78.37 billion cubic metres (bcm) up to Thursday, down 7.5% from 84.72 bcm a year earlier and slightly lower than the normal 10-year average of 79.04 bcm. The current storage is nearly 50% of the total live capacity of these reservoirs, lower than that of 54% a year earlier.
Such a situation might affect sowing of various summer crops if the geographical spread of rainfall remains far from satisfactory this month.
As such, the India Meteorological Department (IMD) this week retained its earlier forecast of a deficient monsoon season for 2015, with rainfall at 88% of the LPA. It predicted rainfall to be 84% of the benchmark average in the second half of the June-September season, compared with the actual showers of 95% of the LPA in the first two months of the season.
The IMD defines deficient monsoon rains as below 90% of the LPA of 89 centimetres of showers recorded between 1951 and 2000. Private weather forecaster Skymet last week also revised its monsoon forecast, predicting showers at 98% of the LPA for season, from 102% of LPA predicted in April.
Last year, wide-spread dry-spells initially had affected water reserves and the storage level improved only from mid-July following a rebound in monsoon rains that helped sowing as well.
In the current monsoon season, the quantum of rainfall has been 475 millimetres until Thursday, compared with the LPA for the period of 508.5 millimetres, according to the IMD. Monsoon showers were 16% above the LPA in June and 16% lower than the benchmark average in July alone.
Rains have been rather erratic in July, with heavy downpour in select regions (Parts of Gujarat and Rajasthan, for example) and dry-spells in some others.
Helped by good rainfall in June and comfortable water reserves, the sowing of summer crops had jumped significantly in the initial phases before slowing down. The area under various kharif crops rose almost 9% up to July 31 from a year before, but the lead over last year has narrowed from as high as 63% until July 17.
According to the IMD, only 14 of the country’s 36 weather sub-divisions have witnessed normal showers so far. As many as 15 sub-divisions have received deficient rainfall, while 7 have seen excess shower. Marathwada has witnessed the worst rainfall deficit so far (-51%), followed by parts of Karnataka (-47%). Even eastern Uttar Pradesh has seen a 33% drop in rainfall from the normal levels.
“Rainfall activity is likely to increase over eastern and central India from 10 August onwards. Western Himalayan region would receive fairly wide spread rainfall during next 5 days. South Peninsula would receive subdued rainfall activity during next 10 days,” the IMD said on Thursday.