Lok Sabha Question No. 3691 (UNSTARRED), answered on 2021-03-18
Subject: Flood Forecasting
Ministry: JAL SHAKTI
Asked by: Khagen Murmu

## GOVERNMENT OF INDIA MINISTRY OF JAL SHAKTI, DEPARTMENT OF WATER RESOURCES, RIVER DEVELOPMENT & GANGA REJUVENATION

## LOK SABHA UNSTARRED QUESTION NO.

ANSWERED ON 1

## 3691 8.03 .2021

## FLOOD FORECASTING

## 3691. SHRI KHAGEN MURMU

Will the Minister of JAL SHAKTI be pleased to state:

(a) whether India has recently shifted towards deterministic forecast whereas advanced count EU and Japan have already shifted towards ensemble forecast coupled with Inundation modelling (b) if so, the details thereof; and

(c) the steps taken/being taken by the Government to modernise not only the telemetry infr also  raise  the  technological  compatibility  with  tiver  basin  specific  hydrological,  hyd inundation m odelling so that the country can witness probabilistic based flood forecast with more than seven hundred ten days at par with the developed world;

## ANSWER

## THE MINISTER OF STATE FOR JAL SHAKTI & SOCIAL JUSTICE AND EMPOWERMENT

## (SHRI RATTAN LAL KATARIA )

(a)  &  (b)  Central  Water  Commission  (CWC)  issues  flood  forecasts  based  on  deterministi (Conventional  statistical  correlation  methodology  as  well  as  rainfall  runoff  /  hydrodyna technology  using  digital  models)  as  a  non - struct ural  measure  of  flood  management  to  concerned  Stat Governments depending on the requisition from them at identified locations. At present, th hydro- meteorological sites being operated by CWC across the country covering 20 river basins e, discharge  and  sediment  observations.  Many  of  these  stations  are  used  as  flood  monitoring formulating flood forecasts. CWC also issues inflow forecasts to identified reservoirs for regulation.  Flood  forecast  formulation  meth odology  used  by  CWC  includes  deterministic  conventiona statistical  methodology  using  statistical  regression  equations  between  the  levels  of downstream  stations  as  well  as  with  flows  between  upstream  and  downstream  reservoir  stat hydrographs of intervening catchment area is also used for getting rainfall contribution ge these stations. This method provides advance warning time from 6 to 24 hrs depending upon Presently, CWC flood forecasting network has been expanded to 328 Flood Forecast Stations (198 Lev Forecast  for  villages/towns  on  the  bank  of  the  rivers  and  130  Inflow  Forecast  Stations barrages)  covering  23  States  &  2  UTs  including  NCT  of  Delhi  and  20  river  basins  for  ta mitiga tion measures by respective State Governments. Annually, about 8000 flood forecasts ar CWC during floods.

The ensemble forecast which includes the associated probabilities with the flood warnings used at present.

(c) The hydro - meteorological data collection and transmission of CWC is being modernised thr use  of  satellite  based  automatic  data  acquisition  system.  Flood  forecasting  by  CWC  uses technology including remote - sensing, Geographical I nformation System (GIS), internet, artific intelligence and machine learning in development / running / formulation and calibration of models and for providing inundation alerts which are closely at par with international stan formulating three day advisories of flood using satellite based real time rainfall estimat rainfall  forecast  through  Numerical  Weather  Prediction  models  being  shared  by  Indian  Met Department (IMD) on a seamless fashion. Mathemati cal model has been used for formulation of adviso and these advisories are shared with stakeholders using a dedicated website. The three day likely to be extended to five day advisories for all basins from the year 2021. Besides th C is also providing inundation forecast in the same platform using two - dimensional models for main Brahmaputra and is also shared with beneficiaries through the same website. In addition, CWC has signed M/s Google Inc. for using their vast repo sitory of high resolution Digital Elevation Models (DEMs) an power  of  dissemination  to  send  alerts  regarding  inundation  through  Google  platform  usin forecasts issued by CWC.

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