ENHANCING RUNOFF MODELING WITH GIS

Runoff modeling is used to predict the effect that rain falling somewh ere in a catchment will have elsewhere in the catchment. Engineers use it to estimate floods, and therefore design dams, spillways and retar ding basins. However, engineering runoff models are not well suited to the process of environmental planning: substantial hydrological exper tise is required to run them. It takes many hours to run a single test , and Visual display of the planning scheme for the catchment is rudim entary, Geographic Information Systems (GIS) have the potential to ove rcome all these problems. In this paper, we describe how we integrated RORB, the runoff model most widely used in Australia, with a GIS. Res ults obtained with the integrated GIS/RORB system were not significant ly different from those obtained by conventional use of RORB by hydrol ogical engineers. Model operations using the linked system took only a round one quarter of the time and, as would be expected with GIS, the visual display capability was excellent. (C) 1997 Elsevier Science B.V .