1. I) Methods of interpolation II) Cloud tracking III) Future Work : radar images & Flood modelling Maureen Coat ENSTA Paristech

2.  Database available :  88 Raingauge Stations  Rainfall Rate every 30 min  Between 06/06/2006 and 19/10/2009

4.  Code in SQL, easy selection of rainfall rate:  At any date  At any time  In London  Only a discrete set of data…  But rainfall is a continuous phenomenon  => Interpolation in regular grid cells

5.  Many methods exist :  Inverse Distance Weight  Liska’s Method  Polygone of Thiessen  …  The more efficient : Kriging Method :  Designed for geophysical variables with a continuous distribution  Based on statistics  => Many data are required (Database)  With Matlab

6. Rainfall Rate Interpolation in London : (07/07/2009)

7.  The 07/07/2009 : Flash flood in London  Victoria Station, Edgware road, and Paddington have been evacuated

8. Rainfall Rate (mm/h) in London (07/07/2009) : Victoria Station Latitude : 51.5104444 Longitude : 0.1872222

9. Rainfall Rate (mm/h) in London (07/07/2009) :

13.  Weather radar :  Estimated rainfall rates are derived indirectly from measurements of reflectivity  => subject to a combination of systematic and random errors  Conditional Merging ?  Bemus (Belgrade Model of Urban Sewers) :  Rainfall Data is in Input  Influence of intensity  Influence of interpolation Method

14. Maureen Coat maureen.coat@ensta.fr