ISRO Archives - The India Climate Observatory

From space, a district and its water

October 9, 2015 by Climate portal editor 3 Comments

In this panel of maps the relationship between the district of Parbhani (in the Marathwada region of Maharashtra) and water is graphically depicted over time. The blue squares are water bodies, as seen by a satellite equipped to do so. The intensity of the blue colour denotes how much water is standing in that coloured square by volume – the deeper the blue, the more the water.

Water bodies consist of all surface water bodies and these are: reservoirs, irrigation tanks, lakes, ponds, and rivers or streams. There will be variation in the spatial dimensions of these water bodies depending on how much rainfall the district has recorded, and how the collected water has been used during the season and year. In addition to these surface water bodies, there are other areas representing water surface that may appear, such as due to flood inundations, depressions in flood plains, standing water in rice crop areas during transplantation stages. Other than medium and large reservoirs, these water features are treated as seasonal and some may exist for only a few weeks.

RG_ICP_water_district_map_201510_section

Click for a section of the full size image. The detail can be mapped to panchayat level.

The importance of monitoring water collection and use at this scale can be illustrated through a very brief outline of Parbhani. The district has 830 inhabited villages distributed through nine tehsils that together occupy 6,214 square kilometres, eight towns, 359,784 households in which a population of 1.83 million live (1.26 rural and 0.56 million urban). This population includes 317,000 agricultural labourers and 295,000 cultivators – thus water use and rainfall is of very great importance for this district, and indeed for the many like it all over India.

This water bodies map for Parbhani district is composed of 18 panels that are identical spatially – that is, centred on the district – and display the chronological progression of water accumulation or withdrawal. Each panel is a 15-day period, and the series of mapped fortnights begins on 1 January 2015.

The panels tell us that there are periods before the typical monsoon season (1 June to 30 September) when the accumulation of water in surface water bodies has been more than those 15-day periods found during the monsoon season. See in particular the first and second fortnights of March, and the first fortnight of April.

During the monsoon months, it is only the two fortnights of June in which the accumulation of water in the surface water bodies of Parbhani district can be seen. The first half of July and the second half of August in particular have been recorded as relatively dry.

This small demonstration of the value of such information, provided at no cost and placed in the public domain, is based on the programme ‘Satellite derived Information on Water Bodies Area (WBA) and Water Bodies Fraction (WBF)’ which is provided by the National Remote Sensing Centre (NRSC), Indian Space Research Organisation (ISRO), Department of Space, Government of India.

For any of our districts, such continuous monitoring is an invaluable aid to: facilitate the study of water surface dynamics in river basins and watersheds; analyse the relationships between regional rainfall scenarios and the collection and utilisation of water in major, medium reservoirs and irrigation tanks and ponds; inventory, map and administer the use of surface water area at frequent intervals, especially during the crop calendar applicable to district and agro-ecological zones.

A monsoon in more than two halves

August 4, 2015 by Climate portal editor Leave a Comment

Less rain for the remaining two months of the typical monsoon season of four months, but an overall season average that remains as it was forecast in June. This is the confusing monsoon update issued by the Earth System Science Organization (ESSO), the Ministry of Earth Sciences (MoES) and the India Meteorological Department (IMD).

There are aspects of IMD’s treatment of the monsoon season that need correction in our view. One is the long range forecast and its updates. Specific to this update, we are at the halfway stage of what is typically considered the four month monsoon (this too needs revision, as April and May rains were not the usual ‘unseasonal’ passing showers). However, any downward revision of the rainfall average for August and September ought to be an overall downward revision of the season, particularly as June-July have seen very uneven rain.

Consider the highlights of the updated monsoon forecast:

* Quantitatively, the rainfall over the country as a whole during the second half of the season (August to September) is likely to be 84% of LPA with a model error of ±8%.
* The rainfall during August is likely to be 90 ± 9% of LPA as was forecasted in June.
* The season (June to September) rainfall over the country as a whole is likely to be 88% of LPA with a model error of ±4% as was forecasted in June.

We make our criticism constructively, for a significant amount of the material India Climate Portal puts out through our website and our twitter account is taken from the public products released by IMD, ISRO and the Ministry of Earth Sciences, and we fully appreciate the quality of work and commitment of these agencies.

The national mean rainfall (“country as a whole”, as the IMD forecasts call it) must be abandoned as it does not represent the meteorological diversity of a very large country. Each of the 36 met sub-divisions is affected in different ways by the El Nino Southern Oscillation, the Indian Ocean dipole, the Madden-Julian Oscillation and other hemispheric phenomena.

There is no need for this simplification, which in fact achieves the opposite of timely accuracy.
The media in particular (television and radio, print, online) look for an overall message and, without guidance from authorities, picks up ‘top line’ messages that are of little or no use at the district and taluka level, and also for towns and cities. The question for IMD is rather: how will variability in monsoon together with the strengthening El Nino affect local outlooks for August to October. That is why we advocate monthly outlooks for the 36 met sub-divisions, to begin in May and to run until October (that is, half the year and not a third of the year), primarily to prepare local administrations for all possible scenarios.

There is no reason why this cannot be the approach. The Ministry of Earth Sciences coordinates the observation network (satellites included, and our agencies ISRO and NRSC are heavily involved), the IMD uses these data together with a very extensive network of weather stations all over India. The output is excellent quality and in the public domain. Because the meteorological services in India have historically been designed to aid and guide agriculture and cultivation, the agri-met bulletins, alerts and products are copious. Hence IMD/MoES listens to the needs of the agricultural departments and, more recently, disaster management agencies. Unfortunately, the interface with public is still minimal, which this central government can also easily remedy.

Two years of India’s weather watcher

July 28, 2015 by Climate portal editor Leave a Comment

We wish Insat-3D a very happy second birthday and warmly congratulate the Indian Space Research Organisation (ISRO) on this anniversary.

Insat-3D completed two successful years in orbit on 26 July 2015. The Advanced Weather Satellite is designed for enhanced meteorological observations and monitoring of land and ocean surfaces for weather forecasting and disaster warning. Insat-3D is the first Indian geostationary satellite equipped with instruments that provide frequent good quality atmospheric profiles (temperature, humidity) over the Indian landmass and adjoining areas.

Thanks to the coordination between ISRO and the Indian Meteorological Department (IMD), we at India Climate Portal make heavy and frequent use of the many observational products, all free in the public domain, to inform you about weather and climate.

Insat-3D provides us high quality observations for monitoring and predicting of weather events as well as studying our climate. The advanced ‘Imager’ and ‘Sounder’ on the satellite provide a wide range of atmospheric products such as cloud coverage images, atmospheric winds, sea and land surface temperatures, humidity, quantitative rainfall, earth’s radiation, atmospheric profiles, ozone, atmospheric stability parameters, fog, snow, aerosols. These products are immensely helpful in monitoring day-to-day weather and prediction of extreme events like tropical cyclone, thunderstorm, cloud burst and heat waves.

The ‘Imager’ has completed 25,733 scans and ‘Sounder’ has completed 14,866 scans until the end of May 2015. The Insat-3D spacecraft was dedicated to the country at the National Satellite Meteorological Center (NCMC), India Meteorological Department (IMD), New Delhi on 15 January 2014. An indigenously designed and developed Insat-3D Meteorological Data Processing System processes all data transmitted by the Imager and Sounder. The data archival and dissemination is through IMD, New Delhi and the Meteorological and Oceanographic Satellite Data Archival Centre (MOSDAC, at Space Applications Centre, Ahmedabad).

A number of Insat-3D observations and derived products are being used in models operated by national weather prediction agencies like the IMD and the National Centre for Medium Range Weather Prediction (NCMRWF). Moreover, the European Centrer for Medium range Weather Forecast (ECMWF) and the United Kingdom Meteorological Office (UKMET) plan to use Insat-3D derived data in their global models.

As always, the ISRO family, staff, engineers, scientists and technicians excel at what they do best. In tandem with the committed and dilligent meteorologists of the IMD, they have given us free information, as good as the best the world can offer, so that we understand our Bharat better.