Johanna Deak Sjöman and Neil Sang
This chapter reviews several different approaches to modelling flooding and climate in urban areas. Simple modelling techniques are discussed which might provide an initial indication of the risk and thus whether further expense is warranted in more precise models and where this would be best focused. In respect of flooding simple “bath tub” and GIS based flow models are discussed as well as more bespoke Computational simulation models (MIKE, Telemac) as well as strategic impact models (DIVA, SIMClim) and early attemps at Low Impact Drainage estimation. In respect of climate, three of the most popular packages are reviewed in detail, ENVImet, SOLWEIG and RayMan, each of which carries different strengths and complexities.
- Simple flood models are often sufficient for an initial estimate but tend to be most reliable for estimating a worst case.
- Ground infiltration models are important but difficult to calibrate, often requiring field work or estimates from other models.
- Simulation models are important for handling complex urban topography, but are impractical at large scales and tend to assume hard surfaces.
- Very little work has been done on Low Impact Drainage modelling.
- Climate models are often best managed as indicators such as temperature and skye view factor.
- Dynamic simulation is computationally difficult. The increase in difficulty for more detailed results is steep. However fast laser scanning and photogrammetric modelling have made data collection much simpler.