Hydrological forecasting and data assimilation – the HydroCast project

Hydrological Forecasting and Data Assimilation
– The HydroCast Project
Henrik Madsen
Head of Innovation, DHI
With contributions from the HydroCast team
Danish Water Research and Innovation Platform, Annual Meeting,
January 31, 2013

Project overview
• Research grant from the the Danish Council for Strategic Research
• Project period: 1 Jan 2012 – 31 Dec 2015
• Partners:
o DHI (Co-ordinator)
o Geological Survey of Denmark and Greenland (GEUS)
o Department of Geography and Geology, University of Copenhagen
o Department of Civil Engineering, Aalborg University
o Danish Meteorological Institute
o European Centre for Medium-Range Weather Forecasts (ECMWF)
o Institute of Applied Mathematics, Delft University of Technology
o Danish Road Directorate
o Knowledge Centre for Agriculture
o Danish Nature Agency
© DHI #2

Project objective
To establish and test a general framework for hydrological forecasting and data
assimilation that integrates different data sources with meteorological and hydrological
modelling systems
Short-range, limited
area NWP forecast
Weather
radar nowcast
Medium-range, large
scale NWP forecast
Seasonal, large
scale forecast
Hydrological data assimilation
Time of
forecast
© DHI #3
Hydrological ensemble forecast

Project activities - overview
Work packages
• WP1: Combining weather radar and numerical weather prediction for short-range
forecasting
• WP2: Probabilistic hydrological forecasting
• WP3: Hydrological data assimilation
Test studies
• Test study 1: Forecasting of floods for rural infrastructure
• Test study 2: Seasonal forecasting of irrigation potentials
• Test study 3: Integration of modelling in environmental monitoring
© DHI #4

WP1: Combining weather radar and numerical weather
prediction for short-range forecasting
• Forecasting system that combines weather
radar and high-resolution short-range NWP
modelling
• Weather radar forecast model based on a
combination of a storm cell and a radar
reflectivity tracking model
• Data assimilation of weather radar in NWP
model
• Quality control algorithms for state-of-the-art
dual polarisation weather radars
© DHI #5

First results of combined NWP-weather radar forecast system
Extreme rainfall event in Copenhagen 2 July 2011
Maximum 30-min intensity
© DHI #6

First results of combined NWP-weather radar forecast system
Extreme rainfall event in Copenhagen 2 July 2011
Forecast 18 UTC, 3 hour lead time
Radar, 18 UTC
© DHI #7

First results of combined NWP-weather radar forecast system
Extreme rainfall event in Copenhagen 2 July 2011
Forecast 18 UTC, 2 hour lead time
Radar, 18 UTC
© DHI #8

First results of combined NWP-weather radar forecast system
Extreme rainfall event in Copenhagen 2 July 2011
Forecast 18 UTC, 1 hour lead time
Radar, 18 UTC
© DHI #9

WP2: Probabilistic hydrological forecasting
• Use of ensemble precipitation forecast products to
produce ensemble hydrological forecasts
‣Nowcast (few hours): weather radar ensemble
prediction
‣Short-range (< 48 hours): DMI ensemble prediction
system
‣Medium-range (2-10 days): ECMWF ensemble
prediction system
‣Seasonal: ECMWF seasonal ensemble prediction
system
• Framework for quantification and propagation of
different uncertainty sources in the hydrological
forecast system
© DHI #10

DMI’s limited-area, short-range ensemble prediction system
• Based on the HIRLAM model
• 0.05º horizontal resolution
• 25 ensemble members
‣Initial and lateral boundary condition
perturbations
‣Model physics perturbations
• 54h forecasts, four times per day
© DHI #11

DMI’s limited-area, short-range ensemble prediction system
© DHI #12

WP3: Hydrological data assimilation
• Multi-variate hydrological data assimilation based
on the MIKE SHE hydrological modelling system
• Generic data assimilation framework that uses
the open modelling interface (OpenMI) standard
and links to the OpenDA data assimilation
toolbox
• Assimilation of in-situ data (runoff, groundwater
levels, soil moisture profiles) and remote sensing
data (soil moisture, land surface temperature)
© DHI #13

Hydrological data assimilation - Example
Simulated heads with DA
Prediction uncertainty
© DHI #14

Optimising the monitoring effort
Environmental state
uncertainty
Optimal design of monitoring
effort (modelling + monitoring
network)
© DHI #15
Costs

Test study 1: Forecasting of floods for rural infrastructure
• Test the data assimilation and forecasting techniques developed with respect to shortrange
forecasting of flooding at a motorway infrastructure at Silkeborg
• Flooding is caused by a combination of rising groundwater levels and overland flow
generated by heavy rainfall
© DHI #16

MIKE SHE model setup
© DHI #17

Test study 2: Seasonal forecasting of irrigation potentials
• Test the probabilistic hydrological forecasting
tools for seasonal forecasting of river flows to
determine the potential amount of irrigation
water to be abstracted for maintaining a given
minimum flow
• Two forecast horizons considered
‣Forecast mid-February to be used for
planning of agricultural crops
‣Forecast mid-April to be used for issuing
irrigation permissions
© DHI #18

Test study 3: Integration of modelling in environmental
monitoring
• Test the developed multi-variate data
assimilation system for monitoring of the
hydrological state at catchment scale
• Application to the Skjern catchment
using data collected as part of the HOBE
center (www.hobecenter.dk)
© DHI #19

Main project results
• A methodology for combining weather radar and NWP modelling for short-range
forecasting.
• A seamless probabilistic hydrological forecasting system, considering short-range,
medium-range and seasonal forecasting.
• A multi-variate hydrological data assimilation system.
• Test of the developed hydrological forecasting and data assimilation methodologies in
three studies.
• Recommendations for local and central authorities on use of hydrological forecasting
and data assimilation.
• Three graduated PhD students and two completed Post Doc studies.
© DHI #20

Thank you for your attention
Henrik Madsen
hem@dhigroup.com
This work was carried out with the support of the Danish
Council for Strategic Research as part of the project
“HydroCast – Hydrological Forecasting and Data Assimilation”,
Contract No. 11-116880
http://hydrocast.dhigroup.com/
© DHI #21