Radar Rainfall Calibration Webinar - Water...
Transcript of Radar Rainfall Calibration Webinar - Water...
Radar Rainfall Calibration Webinar
Dr Alan Seed
Alan Seed, Mark Curtis
Rainfields3
The next generation radar rainfall estimation and nowcasting system
Radar network
Radar and gauge coverage in real-time
Rainfields
Rainfields QC/QPE/QPF
50 radars
1700 rain gauges
10 000 products per hour
NWP wet bulb freezing levels
Forecasters
Public weather
Hydrology
NWP assimilation
Rainfields algorithms Climatology Quality Control QPE
Beam blocking
Probability of echo
Topography
Velocity QC
Target identification
Reflectivity QC Bias correction
Gauge blending
Accumulations
Products
• Quality controlled volume scans (QC added to the
volume scan data)
• Surface radar reflectivity for single and multi-radar
domains
• Instantaneous rain rate (used for accumulations and
nowcasts)
• Rainfall accumulations (6 min to 24 h)
• Ensemble forecasts
• 0-12 h, 10 min update over 500 km domains for
Melbourne, Sydney, Brisbane
• 0-90 min, 6 min update, over 50 radar domains
Key requirements • Flexible
– Heterogeneous radar network
– Diverse and customizable product suite
• Scalable
– Up to full network and product suite
– Down to small research deployments
• Low latency
– Near real-time display for forecasters
– Data assimilation into NWP
• Accessible
– Searchable archive for research
– Standardized product formats
Real-time product dashboard
Configurable QC for each radar
Query portal Read
volume Speckle filter
Dealias
VRAD
Classify
targets
Threshold
DHZH
Generate
VAD Write VAD Publish VAD Write volume ...
C++ implementation
XML configuration
Bayes Target Classification
Doppler moment dealiasing • Various window and sweep approaches
• 4D Dealiasing approach compares aliased velocity with prior scan
Echo tracking • Used to simulate 1-minute data when calculating the 6-min accumulations
• Used to correct the different time stamps when making the mosaic
• Used for the nowcasting products
Dynamic radar quality index
Dynamic bias adjustment • Mean bias at each gauge is monitored
• Real-time adjustment updated using Kalman filter every 30 mins
• Spatial field estimated using Ordinary Kriging every 30 mins
Verification
• 30min gauge versus 30min
radar
• Based on bias corrected
accumulations
– Not gauge merged
• 4 window lengths
– 7, 30, 120 and 365 day
• Updated daily
Mean Error Time Series
Multi-radar mosaic • Use the quality index to calculate the weights for a mosaic product
Typical products
Rainfields3 Summary • Rainfields3 is the next generation operational radar rainfall estimation and
nowcasting system
– Will be fully operational by July 2017
– Processes data from 50 radars
– Uses the STEPS algorithms to generate 30-member nowcast ensemble for
each of the 50 radars (6 min updates)
– Generates 10000 QPE&QPF products an hour
Thank you
Any questions
What is the problem…..
Calibrated RADAR Rainfall Data – A Comparison with Traditional Techniques
Greg Hansell
Water Technology Pty Ltd
Presented at 21st Queensland Water Symposium, 2016
Further contributors include Alister Daly, Andrew Thompson, Blair Filer and Chris Delany
• How does Calibrated RADAR compare to traditional techniques for the January 2011 event:
• Stanley River
• Lockyer Valley
• Murphy’s Creek
• Implications for catchment hydrology
Mt Stapylton RADAR ImageJan 2011 (Source – BoM)
Background
• Thesis project underway by Chris Delany
• Total catchment ~3,000km2 in area
• ~370km2 Murphy’s Creek
• 38 Council rain gauges
• Only 1 in Murphy’s Creek
• ~2-3 day event duration
Analysis
• Fresh TUFLOW build
• Rain on Grid (Inverse Distance Weighting)
with traditional gauge and RADAR input
• Work in progress, however preliminary results
look promising…
Lockyer Valley Case Study Spatial Comparison
Murphy’s Creek: Spatial Comparison
Murphy’s Creek: Hydraulic Model Comparison
Conclusions – Calibrated RADAR Rainfall data
• RADAR - New and innovative approach
• RADAR compares well to traditional catchment hydrology approaches where gauge data is available
• RADAR may provide enhanced results where gauge data is limited/poor
• Effectively turns every 1km2 grid into a “rain gauge”
• Provides complete rainfall catchment coverage (versus rain gauges only)
• Can be enhanced: -
• With inclusion of other rain gauges (HydroNET can do this);
• Optimum calibration outcome
=> Further source of information=> Can add value to hydrologic assessments
What is RainMap?• Easy online access to:
– BoM weather forecasts
– BoM weather stations
– BoM radar data
• Tools to enable water professionals– Export to model input files
– Upload shape files for catchment averages
– Generate rainfall reports
– Download long time series
– Access to data back to 1900
How widely is the HydroNet Platform Used?
• 2500 water managers world wide use the radar tools of HydroNET
• These tools are now tailored for the Australian situation during the ESA project in cooperation with 10+ Queensland councils.
What do HydroNet offers……
• We buy the radar data from BoM,
• archive it in the cloud and
• translate it into tools for water managers so that they can easily use radar data for operational and strategic water management: whenever and wherever.
• You just need a web browser.
Upcoming seminars
• The same can be done with forecasts…
More informationwww.hydronet.com.auwww.watertech.com.au
Examples of tools that RainMap provides
• exports into platform agnostic (Tuflow, Mike etc) models for model calibration,
• export to Word document to evaluate rainfall events,
• upload your own catchments to calculate catchment averages, download time series in excel or model formats,
• automatic exports to your databases/systems,
• export to your website to share with the community, we archive it for you
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