Information tracking for flood impact of land use and management change
O''Donnell, Greg Martin
PublisherUniversity of Newcastle Upon Tyne
MetadataShow full item record
Knowledge of how local changes in runoff generation propagate through the stream network to create impacts downstream at the larger catchment scale is lacking. This issue needs to be urgently addressed, particularly as many organisations involved in flood risk management favour interventions that manage runoff at source. To enable research into propagation of catchment flood runoff and its impacts, a new modelling approach has been developed. The catchment is discretised into the component hillslopes/fields, which are connected to a dense dendritic stream network. Runoff generated from the landscape units is represented as packets of water, which are tracked through the stream network using a numerical solution of the non-inertial form of the Saint Venant equations. The packets carry information, including the volume, location and time of runoff generation. To recover the information, the packets travelling past particular downstream points in the network are interrogated. The recovered information can be used in many ways. For example, it is possible to create spatial maps, showing the source locations and intensities of runoff contributing to the catchment hydrograph peak, or to break down the hydrograph into contributing hydrographs, one per sub-catchment or per area undergoing change. The importance of this novel approach is that it explicitly links the local scale, at which landscape adaptation measures are implemented, and the catchment scale, where impact occurs. An application of this type is demonstrated for the Eden Catchment, UK, providing novel and informative visual representations of spatial runoff generation and propagation.