Urban flood modelling is becoming more important as the population is increasingly urbanised.
Flood modelling requires data on rainfall, land cover (whether the ground has roads, fields, buildings etc.), and soil type. Digital elevation data is needed to show where there are hills and where the water will flow.
Remote sensing can collect data by sensors which detect radiation, and where objects are in relation to radiation that is emitted or reflected. Remote sensing can be used for gathering data on topography (the surface of the ground), rainfall and land cover.
There are two main urban flood modelling approaches. 1) Dual drainage – this modelling approach combines a 1D sewer network and a 1D surface network, so the model looks at where water flows in the sewer network and on the surface. 2) Combined 1D/2D model – this approach uses a 1D sewer system to look at water below the ground plus a surface model to see where the water flows, and models the change in elevation.
Urban flood modelling can be used to develop hazard maps to show which areas are most vulnerable to floods; provide rescue and emergency services with more information in the event of a disaster; and determine where flood defence protection is needed. Overall, urban flood modelling techniques allow for more informed decisions and planning and management in the event of a flood.