Lok Sabha Question No. 1044 (UNSTARRED), answered on 2023-07-26
Subject: Rainfall Pattern
Ministry: EARTH SCIENCES
Asked by: Jagdambika Pal

## GOVERNMENT OF INDIA

## MINISTRY OF EARTH SCIENCES

## LOK SABHA

## UNSTARRED QUESTION NO. 1044

## TO BE ANSWERED ON WEDNESDAY, 26 TH  JULY, 2023

## RAINFALL PATTERN

## 1044.     SHRI JAGADAMBIKA PAL:

Will the Minister of EARTH SCIENCES be pleased to state:

- (a) whether the rainfall pattern has changed in different parts of the country, wherein some parts are receiving heavy rainfall and some parts receiving less rainfall;
- (b) if so, the details thereof;
- (c) whether  the  Meteorological  Department  has  conducted  any  survey  through  experts  to ascertain the reasons for extreme diversity in rainfall during the monsoon season recently, if so, the details thereof; and
- (d) the details of the steps taken by the Government to prevent such changes in rainfall pattern?

## ANSWER

## THE MINISTER OF EARTH SCIENCES (SH. KIREN RIJIJU)

- (a) - (c)   Yes  Sir,  changes  are  observed  in  the  rainfall  pattern  of  the  country.  India  Meteorological Department (IMD) has carried out an analysis of observed monsoon rainfall variability and changes  of  29  States  &  Union  Territory  at  State  and  District  levels  based  on  the  IMD's observational  data  of  recent  30  years  (1989-  2018)  during  the  Southwest  monsoon  season from  June  to  September  (JJAS)  and  issued  a  report  on  30  March  2020.  The  reports  on observed rainfall variability and its trend for each State and Union Territory are available in IMD  website  (https://mausam.imd.gov.in/)  under  'PUBLICATIONS'  as  well  as  in  IMD Pune website;

http://www.imdpune.gov.in/hydrology/rainfall%20variability%20page/rainfall%20trend.html

The highlights of the report are given below:

-  Five  states  viz.,  Uttar  Pradesh,  Bihar,  West  Bengal,  Meghalaya  and  Nagaland  have shown significant decreasing trends in southwest monsoon rainfall during the recent 30 years period (1989-2018).
-  The annual rainfall over these five states along with the states of Arunachal Pradesh and Himachal Pradesh also show significant decreasing trends.
-  Other states do not show any significant changes in southwest monsoon rainfall during the same period.
-  Considering  district-wise  rainfall,  there  are  many  districts  in  the  country,  which  show significant changes in southwest monsoon and annual rainfall during the recent 30 years period  (1989-2018).    With  regard  to  the  frequency  of  heavy  rainfall  days,  significant increasing trend is observed over Saurashtra & Kutch, Southeastern parts of Rajasthan, Northern parts of Tamil Nadu, Northern parts of Andhra Pradesh and adjoining areas of Southwest  Odisha,  many  parts  of  Chhattisgarh,  Southwest  Madhya  Pradesh,  West Bengal, Manipur & Mizoram, Konkan & Goa and Uttarakhand.
- (d) Associated with the climate change due to global warming, temporal and spatial diversity in severe weathers including extremely heavy rainfall have been observed in the country in the recent years in line with increase in the extreme events observed over various other parts of the globe. The recent IPCC climate change report indicates that these trends will continue in future and those are not preventable. However, to forewarn about such events, IMD issues forecast and warning related to severe weather to support disaster management activities and sectorial  applications.  For  this  purpose,  IMD  follows  a  seamless  forecasting  strategy.  The long-range forecasts (for the whole season) issued are being followed with extended range forecast  issued  on  every  Thursday  with  a  validity  period  of  four  weeks.  To  follow  up  the extended  range  forecast,  IMD  issues  short  to  medium  range  forecast  and  warnings  at  36 meteorological  sub-divisions  levels  daily  four  times  by  the  National  Weather  Forecasting Centre (NWFC), New Delhi valid up to next five days with an outlook for subsequent two days. The short to medium range forecast and warning at district and station level are issued by state level Meteorological Centres (MCs)/Regional Meteorological Centres (RMCs) with a validity of next five days and are updated twice a day. The short to medium range forecast is followed by very short range forecast of severe weather up to three hours (nowcast) for all the districts and 1085 cities and towns. These nowcasts are updated every three hours.

IMD has implemented Impact Based Forecast (IBF) in the recent past which gives details of what  the  weather  will  do  rather  than  what  the  weather  will  be.  It  contains  the  details  of impacts expected from the severe weather elements and guidelines to general public about do's  and  don'ts  while  getting  exposed  to  severe  weather.  These  guidelines  are  finalised  in collaboration  with  National  Disaster  Management  Authority  (NDMA)  and  is  already implemented successfully for cyclone, heat wave, thunderstorm and heavy rainfall.

While issuing the warning suitable colour code is used to bring out the impact of the severe weather expected and to signal  the Disaster  Management  about  the  course  of  action  to  be taken  with  respect  to  impending  disaster  weather  event.    Green  color  corresponds  to  no warning hence no action is needed, yellow color corresponds to be watchful and get updated information, orange color to be alert and be prepared to take action whereas red color signals to take action.

The forecasts and warnings are disseminated to users including disaster managers by e-mail on  regular  basis.  In  addition  to  this,  WhatsApp  groups  are  created  including  disaster managers and IMD officials and forecast & warnings are disseminated through this facility also. The forecast & Warnings are uploaded in social media & website for reference by all concerned. The nowcasts related to Severe Weathers are disseminated through SMS also to the registered users.

In addition to this, as and when the situation arises, Press Releases are issued by IMD and the same are also disseminated by all the platforms mentioned above.

IMD  has  taken  various  initiatives  in  recent  years  for  improvement  in  dissemination  of weather forecast and warning services based on latest tools and technologies. In 2020, IMD has  launched  seven  of  its  services  (Current  Weather,  Nowcast,  City  Forecast,  Rainfall Information, Tourism Forecast, Warnings and Cyclone) with ' UMANG ' mobile App for use by  public.  Moreover,  in  2020,  IMD  had  developed  mobile  App  ' MAUSAM '  for  weather forecasting,  ' Meghdoot '  for  Agromet  advisory  dissemination  and  ' Damin i'  for  lightning alert.

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