What is RAS-Flood

RAS-Flood  is an assembly of three complementary software utilities which map and assess solutions to fluvial flooding by virtual case study

  1.  Advanced GIS feature creation from Lidar to describe the catchment digitally (Globalmapper is hard to beat)
  2.  Logical pragmatic stream Bathymetry to 1M grid from lidar point-clouds developed in stage 1 (Atrepo point-smoothing methodology)
  3.  2D Mesh creation and flow computation  (HECRAS 2D courtesy USACE)

g40-ap40-varch1-gis  g40-ap40-varch2-bathym  g40-ap40-varch3-mesh



How long will it take to produce indicative hydrographs from catchment rainfall for comparison of alternative intervention and landuse measures?

Allow a day per 10 sq km for stage 1 (2.5 GHz x 8GB hardware) and 15 minutes per stream for stage 2.    Mesh creation within the perimeter with breaklines from stage 1 is automated and takes only a few minutes. However allow an hour or so to check over such geometry manually.

Then, with geometric data saved and (initially, say) 24 hour rainfall, terrain & bathymetry loaded, the testing of an ‘Unsteady-Flow’ plan to yield indicative hydrographs can be set to take less than an hour (per 100 sq km). A cloud server running the flow analysis code is available on request (email gaw1@cantab.net)



Will catchment flood alleviation measures be considered by policy-makers as providing ‘public good’ and thereby eligible for ‘public funds’ ?

Hard to say, but there is talk of 50p per cubic metre of ‘blue-green’ extreme event flood water storage.

Acknowledgements                                                               More on Virtual Case Studies








Download tests:   canal map                          g40-fbridges