An uneven monsoon is finally drawing to a close in India. The country has received 95% of the long period average, which the India Meteorological Department defines as below normal. This is less than 98% of the long period average, which the Met had forecast at the beginning of the monsoon season in June. The department had also predicted a 4% margin of error.
Of the 630 districts for which the India Meteorological Department tracks rainfall data, 308 received between 19% more and 19% less than normal rain. But 219 received deficient rain, or 20% less than normal rain. Of those, 12 had scanty rain, or 60% less than normal rain. On the other end, 103 districts received excess rain, or 20% more than normal rain. Of those, 27 were 60% above normal.
The monsoon progressively reduced in intensity over the four months it covers the Indian subcontinent. June and July ended with rainfall more than 100% of the long period average for those months. It weakened in August and September to an average of 87.5% of the long period average.
The agriculture department has said that kharif production will be 3% lower than the previous year after central India, including parts of Madhya Pradesh and Uttar Pradesh, received uneven rains, while western and northern India faced floods. These are among the highest food producing states of the country.
High variations
This was indeed a monsoon defined by both floods and dry periods, sometimes in the same area.
Take for instance Rohtas, in Bihar’s Patna division. In the week ending July 26, Rohtas received heavy rains – 280% more than the normal for that week. Yet apart from another heavy bout of rain two weeks later, Rohtas received less than normal rainfall or almost no rainfall for the rest of the season. Cumulatively, according to data from the Met, it has received exactly as much rain through the monsoon as it usually does every other year.
This is not the only anomaly in Bihar. More than 514 people lost their lives in the state in August after 300 mm of rain in 24 hours in its Terai region caused rivers to overflow, and put 1.7 crore people in 19 districts at risk. Of these were areas such as Pashchim Champaran that had rarely flooded before this, according to a report in India Climate Dialogue.
North and North West India both received deficient rainfall. More than half of Uttar Pradesh, two-thirds of Haryana, almost half of Punjab and most of eastern Rajasthan received less than normal rainfall. Many of these parts of the country also faced heavy flooding in the first half of the monsoon.
Despite the monsoon having withdrawn on Saturday, there continues to be heavy rain in parts of the North East as well as northern Karnataka.
Rains resumed in Assam on September 26, triggering another bout of floods. The state has faced crippling floods right through this monsoon – as it has for several years now. Despite this, most districts in Assam have ended the monsoon with below average rainfall. (The constant floods are also an indicator of poor flood management.)
The picture is mixed in the rest of the North East, where the India Meteorological Department does not have observation stations in 25 districts. Many of the higher altitude districts of Arunachal Pradesh have ended the season with deficient rainfall. Tawang has received 74% less rainfall than normal, and is one of 12 districts across the country with scanty rainfall.
Southern states including Karnataka, Kerala and Tamil Nadu had highly deficient rainfall almost until August. Now, parts of these states are facing floods. In the middle of September, three people died after heavy rain in Kerala. The Periyar dam also rose above the danger mark and schools and colleges had to be shut for a day.
Reservoirs still a concern
Despite this, as of September 28, live storage – water that can be used productively for irrigation, drinking and generating electricity – in reservoirs in the southern part of the country is still at 51% of their total capacity. This is against a 10-year average of 72% in this part. Across the country, reservoirs are at 66% of their live storage capacity, against 87% over the last 10 years.
Reservoirs on the Narmada river basin, where Prime Minister Narendra Modi inaugurated the Sardar Sarovar Dam, the world’s second-largest such reservoir, in mid-September, are at 58%. The 10-year average storage for this river is 87% of storage capacity.
Reservoirs on peninsular rivers including the Godavari, Krishna and Cauvery continue to hold far less than their storage capacity. The highest departure from the 10-year average comes from reservoirs on the Krishna River, which runs through Maharashtra, Karnataka and Andhra Pradesh. Storage in these reservoirs are at 55%, against the average of 77%.
The storage in the Nagarjuna Sagar dam on the Krishna is at 4%, down from a normal of 64%.