A self-correction technique for real-time simulation of regulated rivers Olcay I. Unver An automatic self-correction scheme is presented for online adjustment of stream- flow forecasts during simulation of river systems with regulating structures, when actual flow data for interior points are available in real time. Another scheme is presented which allows for the modelling of channel losses due to physical effects such as evapotranspiration, bank storage and diversions. A previously developed river simulation/reservoir management model has been modified to include both schemes. The model is particularly useful for real-time, short-term flood forecasting and reservoir operation. The model application is made to the Lower Colorado River in Texas. The progress which has been made in electronics technology during the past decade has provided valuable tools for real-time river management such as monitoring, flood forecasting and reservoir opera- tion. Remote-sensing data collection equipment and computers are now more affordable, and computing power, speed and capabilities have been enhanced. Online monitoring of hydrologic quantity and quality data such as streamflow and rainfall is economically more feasible than ever. River and reservoir manage- ment for purposes such as flood control, water supply, low flow augmentation, recreation, etc is becoming more and more efficient with the utilization of computer models that can process the large amounts of data available in the real-time framework. Problem statement One of the problems in routing flows in river- reservoir systems on a real-time basis is the time—space tradeoff. For flood operations of a river Olcay Unver is President, Prime Ministry of Turkey South- eastern Anatolia Project Regional Development Administra- tion, Karli Sokak 59, GDP, 06700 Ankara, Turkey. reservoir system, for example, the system manager will want to start routing computations as soon as a potential flood hydrograph is detected, and from the point the hydrograph enters the river system. In medium to large river systems, such as the Lower Colorado River in Texas, the travel time of flood waters may vary between several hours and several days before the flood hydrograph reaches the reser- voir system or flood control points (Figure 1). Similarly, it may take several days for reservoir releases to reach demand points in water supply operations (Figure 2 ). A real-time simulation model for flood operations of multi-reservoir systems was previously developed (Unver et al, 1987) that com- bines rainfall-runoff modelling, interactive data input—output, full dynamic wave flood routing, and on-screen colour graphics capabilities. The model uses a modified version of the US National Weather Service dynamic wave operational model, DWOPER (Fread, 1982) for routing computations. In this study, two important modifications to the aforementioned model are presented to utilize fully all real-time streamflow data available and to correct computed flow variables on a real-time basis. The formulation, as a by-product, allows for the inclusion of flows into 248 0790-0627/92/040248-09 © 1992 Butterworth-Heinemann Ltd Downloaded by [Queensland University of Technology] at 05:48 21 November 2014