Lok Sabha Question No. 817 (UNSTARRED), answered on 2021-02-05
Subject: Impact of Western Disturbances
Ministry: EARTH SCIENCES
Asked by: Bhagwant Mann

## GOVERNMENT OF INDIA MINISTRY OF EARTH SCIENCES

## LOK SABHA UNSTARRED QUESTION NO.817 TO BE ANSWERED ON FRIDAY, FEBRUARY 05, 2021

## IMPACT OF WESTERN DISTURBANCES

## 817. SHRI BHAGWANT MANN :

## Will the Minister of EARTH SCIENCES be pleased to state:

- (a) whether  the  Government  has  made  any  assessment  of  the  impact  of  western disturbances during winter season on Indian climate;
- (b) if so, the details thereof indicating the ill-effects of such western disturbances; and
- (c) the steps taken to prevent the adverse effects of the western disturbances?

## ANSWER MINISTER FOR MINISTRY OF SCIENCE AND TECHNOLOGY AND MINISTRY OF EARTH SCIENCES (DR. HARSH VARDHAN)

- (a) Yes Sir. There are several studies conducted by various scientific institutes in the country in regard to the impact of western disturbances during winter season on Indian climate. The studies show that;
-  30% of annual precipitation over North West Indian region (J & K, Ladakh, Himachal Pradesh  &  Uttarakhand)  is  received  during  winter  and  it  is  mostly  associated  with Western Disturbances. It also causes rainfall over the adjoining places of north India.
-  Precipitation  associated  with  Western  Disturbances  (WDs)  influences  Himalayan climate,  glaciers,  snow-water  storage,  flora,  fauna,  agricultural  crops  and  human inhabitants etc.
- (b) The adverse weather elements associated with Western Disturbances are;
-  Intense precipitation in the form of snow, rain or hail leading to landslides, avalanches and damage of agriculture and manmade structures.
-  Dense to very dense fog events leading to interruption in aviation / rail / road transport services.
-  Cold Wave to Severe Cold Wave and Cold Day to Severe Cold Day conditions after the passage of western disturbances.
-  However, precipitation from the western disturbances is very vital for the Rabi Crop over northwest India. Also snowfall/snowmelt in the Hilly regions contribute to river flow and drinking water for people living downstream.
- (c)  India  Meteorological  Department  (IMD)  issues  forecast  &  warnings  for  the  weather elements related to WD also. From National Weather Forecasting Centre (NWFC), IMD forecasts  are  given  in  sub-divisional  scale  whereas  the  Regional  Weather  Forecasting Centre (RWFC) and State Weather Forecasting Centre (SWFC) issue forecast and warnings in district level and station level.

In addition to these, a Forecast Demonstration Project (FDP) for winter weather systems has been initiated from 2016 and it has brought together several institutes other than IMD to enhance the monitoring and forecast of weather elements related to WD. Accordingly a FDP bulletin is prepared and issued daily during November to February when the Western Disturbances are more active.

From November 2020 onwards, IMD started issuing a special bulletin related to winter weather systems (All India Multi-hazard Winter Warning Bulletin) which provides colour coded warning for five days for the adverse weather elements associated with WD, along with present weather scenario.

IMD started issuing Impact Based Forecast (IBF) in the recent past. Impact Based Warning contains guidelines to the general public while getting exposed to the severe weather. These guidelines  are  finalized  by  NDMA  (National  Disaster  Management  Authority)  in coordination  with  IMD  and  the  same  is  being  issued  for  the  adverse  weather  elements related with WD.

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