Formulation and testing of a distributed triangular irregular network rainfall/runoff model

Abstract

In this thesis, a new distributed, continuous simulation model is developed for flood forecasting. This new model, tRIBS (triangulated Real-Time Interactive Basin Simulator), is created by integrating two models previously developed. A landscape evolution model, CHILD, is used to create the triangular irregular network (TIN) of tRIBS while the original RIBS model is used to provide runoff and saturated/unsaturated groundwater dynamics in the system. These two base models of tRIBS are described and the modifications to CHILD and RIBS are presented. The CHILD model is modified to accept time varying distributed inputs and a saturated zone groundwater flow routine is created. The RIBS model is modified to allow for continuous simulation and capillary suction. This thesis also develops the datasets needed for the tRIBS model. Starting from Digital Elevation Models, watersheds are delineated and then manipulated using geographic information systems to form a TIN. Algorithms to create distributed rainfall inputs and stream channels are also developed for use in the tRIBS model. With the model and dataset completed, the model is successfully tested and calibrated to the Peacheater Creek watershed. Results are very promising.