Applications of GIS in hydrologic modeling

Literature on applications of geographic information systems (GIS) to hydrologic modeling, stormflow generation in steep watersheds of humid regions, and automated configurations of watersheds was reviewed. A hydrologic model in conjunction with GIS technology was constructed to simulate stormflow hydrographs from a watershed. The model consists of three components: stormflow generation, translation and detention. Two major aspects were emphasised in the model: one is taking advantage of standard GIS to extract, overlay and delineate land and water-related characteristics required for stormflow modeling; another is integrating GIS with hydrologic modeling to simulate both spatial and temporal transformation of rainfall into stormflow. A good agreement between simulated and observed stormflow hydrographs was achieved when the model was tested using real data from Jamieson Creek, a well gaged and forested watershed in North Vancouver. Applications of this model in an ungaged and forested watershed, Nitinat watershed on Vancouver Island, show that the model is capable of handling the effects of complexities of soil, land use, topography and rainfall intensity on stormflow simulation. It was revealed that for a given return period the maximum peak flow for a design storm would increase with the duration of the storm and the Rational Method would not be suitable in estimating the maximum peak flow from a watershed with large storage capacity. The GIS technology was highly recommended for water resources management because of its ability of managing and modeling spatial information. Further improvement and testing of the model would result in a comprehensive GIS based model, simulating stormflow, soil erosion and non-point source water pollution.Applied Science, Faculty ofChemical and Biological Engineering, Department ofGraduat