Use of raingauges network data in the short term prediction of urban pluvial floods

Use of raingauges network data in the short term prediction of

urban pluvial floodsI) Methods of interpolationII) Cloud trackingIII) Future Work : radar images & Flood modelling

Maureen Coat ENSTA Paristech

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

Rainfall Data

42 Raingauge stations in London :

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

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

Methods of interpolation

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

The 07/07/2009 : Flash flood in London

Victoria Station , Edgware road, and Paddington have been evacuated

Cloud Tracking ?

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

Victoria Station Latitude : 51.5104444 Longitude : 0.1872222

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

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

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

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

Weather radar : Estimated rainfall rates are derived

indirectly from measurements of reflectivity => subject to a combination of systematic

and random errors Conditional Merging ?

Future work :Comparison with radar images

Bemus (Belgrade Model of Urban Sewers) : Rainfall Data is in Input

Influence of intensity Influence of interpolation Method

Flood modelling :

Thank you for your attention

Maureen Coat maureen.coat@ensta.fr