The Hindu Business Line : Moisture stress alert in northwest as rains run dry

MOUNTING moisture stress in the rain-fed farmlands in northwest India barely a month after a capricious southwest monsoon caused the century's worst case of inundation in Mumbai is threatening to upset crop planning in these areas.

The National Centre for Medium Range Weather Forecasting (NCMRWF) is apprehensive that standing crops will suffer unless east and west Rajasthan and the non-irrigated lands of Punjab and Haryana do not receive rain over the next 10 days.

Speaking to Business Line, Dr Akhilesh Gupta, Director, NCMRWF, said these regions have not experienced any significant rainfall after an unusually wet first week of July. As per latest statistics (dated Aug 17), rainfall activity has more or less ceased in the granary-regions of east and west Rajasthan, Punjab and Haryana.

There has been a significant decline in rainfall week-on-week with west Rajasthan already going under the deficient category (-21 per cent on Aug 17 from - 10 per cent the previous week). Joining west Rajasthan, though not as much in impact, were east Rajasthan (+12 to - 1), Punjab (+1 to - 7) and Haryana (+20 to +15).

According to Dr Gupta, even the rain-bearing western disturbances that cross into the country have not been able to penetrate the interior of the northwest region for want of supportive monsoon easterlies flowing inland from the Bay of Bengal.

West Rajasthan was the latest entrant into the `deficient monsoon' club (Aug 17 base) that also featured Assam and Meghalaya (-24); Nagaland-Manipur-Mizoram-Tripura (-24); Jharkhand (-32); Bihar (-20); east Uttar Pradesh (-23) and Tamil Nadu and Pondicherry (-29). Worrying enough, the first four of these have posted cumulative rainfall deficiencies at the end of the 11th week of the monsoon.

Trough alignment: On Tuesday, the western end of the monsoon trough has shifted to the foothills of the Himalayas. But its eastern end passed through Bareilly, Gorakhpur, Asansol, Kolkata and thence southeastwards into northeast Bay of Bengal. This is what has triggered the ongoing wet session in the east and the northeast, negating earlier forecast of a true `weak monsoon' setting by this time.

In its weather update and forecast on Tuesday, the NCMRWF said fairly widespread rains with isolated heavy falls have occurred over east Uttar Pradesh, northeast Madhya Pradesh, Bihar, sub-Himalayan West Bengal, Sikkim, the Northeastern States and coastal Orissa during the 24 hours.

The previous day's upper air cyclonic circulation over Bihar and neighbourhood had weakened and lay over southeast Uttar Pradesh. Under this scenario, rainfall activity is expected to continue over the Northeastern States, sub-Himalayan West Bengal, Sikkim, Bihar, east Madhya Pradesh, Chhattisgarh, Orissa, coastal Andhra Pradesh, south interior Karnataka and east Uttar Pradesh over the next 2-3 days.

Meanwhile, a new cyclonic circulation (not amounting to a `low') is likely to take shape over northwest Bay of Bengal and adjoining Orissa and Gangetic West Bengal by Friday. This may lead to a reduction in rainfall activity over east Uttar Pradesh, sub-Himalayan West Bengal and Sikkim but a corresponding increase in rainfall over Madhya Pradesh, Chhattisgarh, Orissa and coastal Andhra Pradesh.

Another upper air circulation has been located over Tamil Nadu and adjoining Kerala and presages scattered rainfall over Karnataka, Kerala, Telengana, coastal Andhra Pradesh, south Tamil Nadu and Andaman and Nicobar Islands. But this is not expected to last longer than two days. Rainfall activity over Konkan and Goa and coastal Karnataka is also expected to increase after the formation of cyclonic circulation over the Bay.

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