Integration of Numerical Flood Modelling into Geographic lnformation Systems

Geographic lnformation Systems (GIs) are a powerful tool for land management purposes. The integration of the numerical flood modelling process with a GIs has numerous benefits relating to (a) the efficiency of the flood model development and (b) the interpretation, presentation and conveyance of flood related information. To establish this, a joint project between WBM Pty Ltd and the Department of Lands, Qld was established. The lower floodplain of the Noosa River, Qld was chosen for the project. The 1-D hydrodynamic network program, ESTRY and the ARC/INFO system were used for the flood modelling and GIs components. The outcomes of the project to date indicate the benefits above can be realised. The efficiency and flexibility of the flood model development can be increased through the automatic generation of tables representing the river and floodplain geometry. The presentation of the results from a flood modelling exercise are significantly enhanced. Flood inundation maps, contours of depth and velocities of flood waters leading to flood hazard mapping, can be displayed in two-dimensional plan view or three-dimensional perspectives. Overlays of cadastral, topographic and other information can also be displayed. The scheme is particularly suited to local authorities where flooding is a concern. Flood related information can be stored as attributes in the GIs, and form part of an inquiry data base. The scheme could also be incorporated as part of a flood warning scheme, allowing graphical or tabular presentation of properties and roads likely to be inundated or isolated.