The southwest monsoon began with an 11 per cent rainfall deficit in June and has shown uneven patterns across India. Central and southern regions have received excess rainfall, while the northwest and eastern parts continue to experience shortages, raising concerns about reservoir water levels.
Central India, which started with a 13 per cent rainfall deficit in June, has seen a significant turnaround, recording 21 per cent more rainfall than average. Similarly, southern India has experienced a 25 per cent increase in rainfall, leading to flooding.
On July 8, Mumbai recorded over 300 mm of rainfall within six hours, the second-highest in its history after the 944 mm deluge on July 26, 2005. Severe landslides struck Wayanad district in Kerala last week, resulting in 308 casualties — the worst since the 2008 floods.
Meanwhile, by August 4, the national rainfall deficit had turned into a 6 per cent surplus, mainly due to the transition from El Nino-Southern Oscillation to La Nina. Despite this relief for some areas, the ongoing imbalance between regions with excess and deficient rainfall continues to pose challenges for water management and agriculture.
Northwest, eastern regions face rain deficiency
With rain deficiency since the start of the monsoon season, northwest, and east and northeast India regions have recorded 10 per cent and 13 per cent less rainfall than normal, respectively. June saw even greater deficits, with 33 per cent below-normal rainfall in the northwest and 13 per cent below-normal in the east and northeast.
The India Meteorological Department (IMD) forecasts below-normal rainfall for these areas in the second half of the monsoon season.
Since June 1, as many as 12 states have received excess rainfall. However, nine states in the east, northeast, and northwest regions, including major kharif crop producers Jharkhand, Bihar, Uttar Pradesh, Punjab, and Haryana, are still experiencing a rain deficit, which is expected to persist, according to the weather department.
India experienced 9 per cent more rainfall than the average last month. However, the northwest regions received 14.3 per cent less rainfall than usual in July. Rainfall in the east and northeast regions was deficient by 23.3 per cent, significantly impacting areas such as Punjab, Haryana, Chandigarh, Himachal Pradesh, Jammu and Kashmir, Bihar, Jharkhand, eastern Uttar Pradesh, Gangetic West Bengal, and Odisha.
Impact on water reservoirs across India
While the surplus rainfall helped replenish many water reservoirs, shortage of storage remain in Punjab, Haryana, Bihar, and West Bengal.
Currently, the live storage in 150 major reservoirs across India is at 94 per cent of last year’s level at this time, and 107 per cent of the 10-year average.
In 10 reservoirs, including those in Himachal Pradesh, Punjab, and Rajasthan, the live storage capacity is at 33 per cent of their total capacity of 19.663 billion cubic metre (BCM). This marks a significant decrease from 76 per cent during the same period last year and is below the 10-year average of 53 per cent.
The 23 reservoirs in the east hold 6.989 BCM, which is 34 per cent of their total capacity of 20.430 BCM. This is an increase from 31 per cent last year but still below the 10-year average of 39 per cent.
[With agency inputs]
First Published: Aug 05 2024 | 3:21 PM IST
