Lok Sabha Question No. 1501 (UNSTARRED), answered on 2017-12-27
Subject: Rainfall Calibration
Ministry: EARTH SCIENCES
Asked by: PARVESH SAHIB SINGH

## GOVERNMENT OF INDIA

## MINISTRY OF EARTH SCIENCES LOK SABHA

## UNSTARRED QUESTION No. 1501 TO BE ANSWERED ON WEDNESDAY, DECEMBER 27, 2017

## RAINFALL CALIBRATION

## 1501. SHRI PARVESH SAHIB SINGH:

Will the Minister of EARTH SCIENCES be pleased to state:

- (a) the  current  methods  of  rainfall  forecast  being  followed  by  the  Indian Meteorological Department;
- (b) whether there are any defects that affect the current methods and if so, the details thereof;
- (c) whether  the  said  defects  have  caused  inaccuracies  in  this  year's  rain forecast for areas that were affected by excessive rainfall and were not prepared for it and if so, the details thereof; and
- (d) whether  the  Government  is  looking  at  alternative  methods  for  rainfall calibration and if so, the details thereof and if not, the measures taken for
- accurate rain forecast?

## ANSWER

## MINISTER OF STATE FOR MINISTRY OF SCIENCE AND TECHNOLOGY AND MINISTRY OF EARTH SCIENCES (SHRI Y. S. CHOWDARY)

- (a) India  Meteorological  Department  (IMD)  issues  three  types  of  forecasts during the monsoon season i.e., seasonal forecast (for the whole season), extended range forecast (10- 30 days), short-medium range forecast (0-10 days).  These  forecasts  are  issued  based  on  dynamical  and  statistical models.
- (b)
- No Madam.
- (c) Does not arise.
- (d) IMD  has  established  a  large  number  of  observatories  which  have  been recording  the  daily  rainfall  for  more  than  100  years  now.  IMD  has  706 Automatic Weather Stations (AWS) and 1350 Automatic Rain Gauge (ARG) where the rainfall is being measured every hour. In addition, -IMD receives data from about 3748 number of rain gauges operated all over the country in  collaboration  with  other  stakeholders  (state  governments,  Central Water  Commission-CWC  etc.).  Based  on  these  data  sets,  the  daily assessment of monsoon season rainfall for the country is carried out and rainfall statistics at district-wise/statewise/meteorological-subdivisionwise/region-wise and for the Country as a whole are prepared.

The existing rainfall measurement network is sufficient for climatological purposes  (for  accounting  seasonal  scale  rainfall  statistics).  The  rainfall also supplemented from rainfall estimated from Doppler Weather RADARs and more representative. However, continuous efforts are made by the Government to increase the density of rainfall measurement network with the modern observation technologies involving Automatic Weather Stations (AWS) and data from the said countrywide network of rain gauges is weather satellites to make the rainfall assessment system Automatic Rain Gauges (ARG). Under the 'National Monsoon Mission' (NMM) a state-of-the-art dynamical prediction  model  for  a)  improved  prediction  of  monsoon  rainfall  on extended  range  to  seasonal  time  scale  (16  days  to  one  season)  and  b) improved prediction of temperature, rainfall and extreme weather events on short to medium range time scale (up to 15 days) has been developed and is being used operationally by IMD. An improved suite of prediction models  has  been  implemented  operationally  at  India  Meteorological Department (IMD) for enhanced short range weather forecasting capability through assimilation of all available conventional and satellite data.

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