Flood inundation modelling

A flood map provides information on depth of flooding, extent of inundation, and most importantly the direction of flow paths as the flood water travels.

Tarland modelling                        

Hydraulic models help to predict where flooding might occur, how severe it might be, and the impact that different mitigation measures might have on flood risk in different situations.

We have used a two-dimensional modelling approach to study the hydrological processes, particularly the relationship between rainfall, runoff and channel flows within the focus research catchments (for example, Tarland). The aim is to determine where and how significant the risk of flooding is within a catchment.

We have tested and applied a two-dimensional hydraulic model called Tuflow which is a suite of advanced numerical engines for simulating free-surface flow for river, floodplains, estuaries and coastlines. Tuflow divides the catchment into fine grids that can be constructed from a digital elevation model (derived from Lidar data).

We have used Flood Estimation Handbook (FEH) techniques to determine flow hydrographs based upon catchment characteristics such as topography, slope, land use, soil and sub-surface moisture conditions that are required for the model.

• Coull Bridge  – Between Tarland and Aboyne (51km² )
• October 2002 flood period was modelled local data sets
• Public access to live online live data and time-laps video
• Model scenarios for a major flood using TOPMODEL
• Four land management scenarios to evaluate flood mitigation

Flood inundation modelling

A flood map provides information on depth of flooding, extent of inundation, and most importantly the direction of flow paths as the flood water travels. The flood map can be overlaid with other varieties of maps and aerial photographs so that anyone can easily read and understand the map. This allows the residents to find out whether their farm/ property/ community is likely to be flooded in a specific situation.

Figure 1: Flood inundation map for an extreme event of 1 in 100 year based on LiDAR DEM, Tarland catchment (Webcam images will be used to ground-truth hydraulic modelling)

Publication

Ghimire, S. 2013. Application of a 2D hydrodynamic model for assessing flood risk from extreme storm events. Climate 2013, 1, 148- 162.

NERC Enivronmental Virtual Observatory  

Can complex environmental issues such as diffuse pollution, flooding, water scarcity and carbon dynamics be captured and communicated to communities in simple, informative, easy-to-use tools that empower the scientific, policy and the wider end-user communities? That is the challenge for the NERC Environmental Virtual Observatory, in which the James Hutton Institute is a partner.