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Posts Tagged ‘meteorological

A month of truant rain

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RG_four_weeks_rain_graphic_20140709

We now have rain data for four complete weeks from the India Meteorological Department (IMD) and for all the districts that have reported the progress of the monsoon. The overall picture is even more serious than reported earlier because of the falling levels of water in the country’s major reservoirs. [05 to 11 June is the first week. 12 to 18 June is the second week. 19 to 25 June is the third week. 26 June to 02 July is the fourth week.]

Using the new measure of assessing the adequacy of district rainfall (and not the meteorological cgradations that is the IMD standard), in the fourth week of the monsoon the number of districts that reported normal rains in that week (+5% to -5%) is 18; deficient 1 (-6% to -20%) is 31; deficient 2 (-21% and more) is 437; excess 1 (+6% to +20%) is 17; excess 2 (+21% and more) is 113; no data was reported from 25.

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An epidemic of misreading rain

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RG_rain_misreadings_201406

Who can you turn to? It’s easier to list those whom you shouldn’t turn to, the top rankers being the country’s press and television wallahs, followed at a not respectable distance by academic commentators, then come the government blokes and bureaucrats (some of whom do know the difference between isobars and salad bars, I’ll give them that). Lurking behind this cacophonous mob are the boffins of the IMD and its associated scientific chapters, a number of whom have got their sums right, but who aren’t given the space and encouragement to tell the great Bharatiya public what said public is yearning to hear simply because regulations forbid, just like it was in 1982, 1957, whenever.

As I may have mentioned before, this is Not A Good Thing. It has taken about a decade of mission mode tutoring (how the UPA bureaucrats loved that phrase, mission mode) to get the media wallahs to see the difference between weather and climate. A few may even have learned to read a wet bulb thermometer and puzzle their way through precipitation charts.

RG_rain_misreadings_2But overall, the profusion of android apps that profess to show cool graphics of clouds with lightning bolts erupting topside so that our humble ‘kisans’ know when it’s going to rain (i.e., by looking down at their screens instead of up at the sky) has not helped the Bharatiya public make more sense of less rain. We have squadrons of Insats and Kalpanas buzzing around the globe beaming pictures from the infra-red to the infra dig back home, every 60 or 90 minutes, busy enough to crash a flickr photo server, but the knowledge that said public can sift from it is sparse, rather like the rainfall over Barmer, Bikaner and Ajmer.

And so it goes, with the waiting for rain replacing with an equal banality waiting for Godot but with a far larger cast of characters, most of them insensible to the greater climatic drama being played out, 30,000 feet overhead, and at the poles, in the vast turquoise swells of the eastern Pacific where a malignant El Nino is brooding, in the Himalayan valleys where crystal zephyrs have been shoved aside by an airborne mat of PM2.5, or to the desiccation that creeps outwards from our towns and cities (7,935 of them, India’s triumphant ‘growth story’) that have enclosed sweeping hectares with cement, asphalt, and the hot foetid belches of factories and air-conditioners. GDP, they have been told, is the great liberator.

And that is why we have in place of the quiet concern of our forefathers in their dhotis, an electronic jumble of shrill alarm. “Weak monsoon intensifies drought like conditions in India” was one such headline, the text beneath finding the most ludicrous connections: “… threat of food inflation and weak rural demand in the first year of the Narendra Modi government”. Naturally, the cheerleaders of a demand-centric world cannot do otherwise.

RG_rain_misreadings_1And likewise with “Weak rains deliver India’s new Modi government its first economic challenge” that desultorily spies impending delays in the “sowing of main crops such as paddy, corn and sugarcane” and which notes mournfully that “about half of all farms lack irrigation systems” and, even worse, that “reservoir levels are only a fourth of last year’s levels”, this last despite the best efforts, ham-handed though they are, by the Central Water Commission to show India (for Bharat knows) that the reservoir levels in the 85 major reservoirs are low, but not much lower at this point in 2014 than they were in 2013. The GDP bullies dislike contrary numbers, and would go cross-eyed were someone to mischievously mention the existence of 4,845 large dams in India (the blue-ribboned 85 included) whose many water levels we don’t in fact know at all.

And similar vapidity from another quarter, which like its peers cloaks ineptitude with what it takes to be appropriate jargon, “The cumulative rainfall across the country has so far been 45 per cent below the Long Period Average (LPA) for 1951-2000” and brandishes even more frightful credentials with “a further breakdown of rain data recorded in different meteorological subdivisions shows that normal rainfall has been recorded in only seven of the 36 regions”. But which sere farmer and her wise daughters consider in their universe such things as meteorological subdivisions, when their world is what Balraj Sahni and Nirupa Roy in 1953 showed us so lambently, is no more than ‘do bigha zamin’?

But still the misreading gathers pace, as vexed fixations upon an existence merely economic chase away plain common-sense. For rains may come or rains may go, but in tractors – for so we are instructed by the agents of hardened merchants – we trust. To wit: “… tractor sales have typically expanded at a double-digit pace in the years when rains have disappointed… In the 11 years between fiscal 2003 and fiscal 2013, rains fell short by 5% or more on six occasions… In four of those six years, tractor sales grew at a double-digit pace”. Let us then leave behind our cares and go rollicking over the dusty, still dustier now, plains of the Deccan in tractors tooting red.

But a shadow of monsoon yet for Bharat, and at June’s end. It is past time that the prattling ceased and the learning began.

The new measure of monsoon

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Districts reporting monsoon data, over two weeks, colour-coded under a revised categorisation (explained in the text) for weekly rainfall. The left bar in each pair is the second week, the right bar is the first. Most districts are coloured light red, signifying rainfall much below the weekly normal. Peach is for the lesser deficient category. Green is normal. The two blue hues - lighter and darker - are for the two excess categories. It is immediately apparent that 485 out of 618 reporting districts (78%) have experienced less rainfall than they should have at this stage of the monsoon.

Districts reporting monsoon data, over two weeks, colour-coded under a revised categorisation (explained in the text) for weekly rainfall. The left bar in each pair is the second week, the right bar is the first. Most districts are coloured light red, signifying rainfall much below the weekly normal. Peach is for the lesser deficient category. Green is normal. The two blue hues – lighter and darker – are for the two excess categories. It is immediately apparent that 485 out of 618 reporting districts (78%) have experienced less rainfall than they should have at this stage of the monsoon.

The changes that we find in the patterns, trends, intensity and quantity of India’s monsoon now require an overhaul in the way we assess what is satisfactory or not for environmental and human needs. India’s summer monsoon is already late, and where it is late but active it is weak. The indications from the central earth science agencies (including the India Meteorological Department), from the Indian Institute of Tropical Meteorology, from the National Centre for Medium Range Weather Forecasting are that it will be the end of June before the summer monsoon system settles over central India and the western Gangetic plains. Even so, it will be a relief from the searing temperatures but will not assure sowing conditions for farmers and cultivators, nor will it add to the stores of water in major and minor reservoirs.

In this commentary written for India Climate Portal, I have explained why IMD’s hoary top level categorisation of rainfall weekly quantities in the subdivisions must be replaced, both for what they describe and for how frequently they are described. These currently are: ‘normal’ in a subdivision is rainfall that is up to +19% above a given period’s average and down to -19% from that same average; likewise excess is +20% and more, deficient is -20% to -59% and scanty is -60% to -99%. The ‘normals’ are calculated based on the mean weekly rainfall for the period 1951-2000 with monitoring done in 641 districts distributed amongst the 36 meteorological subdivisions.

By categorising rainfall ‘normals’ and departures from  ‘normal’ to become more administratively impelling – these proposed corrections also simplify the interpretations possible for rainfall above and below ‘normals’ – greater awareness and preparedness of administrations, key agencies and citizens to the deficiencies of monsoon can be fostered. For the district tables below therefore, I have re-cast the categories as follows (all based on the long-term average provided by IMD): Normal in a district is +5% to -5%; Deficient 1 is -6% to -20%; Deficient 2 is -21% and more; Excess 1 is +6% to +20%; Excess 2 is +21% and more.

Whereas, for the same second rainfall week the IMD categories were ‘No Rain’ in 80 districts, ‘Scanty’ in 241 districts and ‘Deficient’ in 130 districts, under the proposed revision they will simply be ‘Deficient 2’ with 449 districts – thereby showing dramatically how widespread the conditions of the late and weak monsoon 2014 are – and ‘Deficient 1’ with 36 districts. Please read the rest at India Climate Portal.