Darrell G. Fontane

A framework for propagation of uncertainty contributed by parameterization, input data, model structure, and calibration/validation data in watershed modeling

Failure to consider major sources of uncertainty may bias model predictions in simulating watershed behavior. A framework entitled the Integrated Parameter Estimation and Uncertainty Analysis Tool (IPEAT), was developed utilizing Bayesian inferences, an input error model and modified goodness-of-fit statistics to incorporate uncertainty in parameter, model structure, input data, and calibration/validation data in watershed modeling. Applications of the framework at the Eagle Creek Watershed in Indiana shows that watershed behavior was more realistically represented when the four uncertainty sources were considered jointly without having to embed watershed behavior constraints in auto-calibration. Accounting for the major sources of uncertainty associated with watershed modeling produces more realistic predictions, improves the quality of calibrated solutions, and consequently reduces predictive uncertainty. IPEAT is an innovative tool to investigate and explore the significance of uncertainty sources, which enhances watershed modeling by improved characterization and assessment of predictive uncertainty.

Multicriteria Decision Support System for Regionalization of Integrated Water Resources Management

Successful implementation of integrated water resources planning and management (IWRM) requires delineation of regions that are relatively homogeneous with respect to multiple criteria, including hydrographic, physical-environmental, socioeconomic, and political-administrative aspects. The water resources planning and management (WARPLAM) DSS is presented as tool for regionalization in support of IWRM through: (1) GIS processing of spatial data related to multiple criteria for defining the homogeneity of clustered base units (e.g., catchments) with respect to multiple criteria; (2) application of fuzzy set theory to development of composite measures of homogeneity over all criteria for alternative clustering of adjacent base units; and (3) development of a modified dynamic programming clustering algorithm that guarantees consistent optimal solutions based on user preferences on the relative importance of the suite of criteria considered for regionalization. The viability of WARPLAM DSS as a tool for regional delineation in support of IWRM is demonstrated through a case study application to the Tocantins-Araguaia River Basin, the second largest in Brazil.

Multiple reservoir system operational planning using multi-criterion decision analysis

Abstract Reservoir system operators must consider multiple quantitative and qualitative operational objectives with varying degrees of importance. A two-stage procedure combining multi-objective optimization and multi-criterion decision analysis techniques is presented for reservoir system operational planning. Objectives are divided into primary and secondary groups. In the first stage of the procedure, primary quantitative operational objectives are used to generate non-dominated alternatives via multi-objective optimization using successive linear programming and the e-constraint method. In the second stage, primary and secondary operation objectives are combined within multi-criterion decision techniques to select the most preferred alternatives from the generated set. Four multi-criterion decision analysis techniques were evaluated in this study. The two-stage procedure is demonstrated by application to the Han River Basin in Korea.

Spatial Estimation of Regional Crop Evapotranspiration

Current methods of computing regional crop evapotranspiration (ET), the prime variable in estimating irrigation demand, largely ignore the spatial variability of ET parameters, thus introducing errors. In this research, a method was developed to estimate regional ET while considering the spatial variability of parameters. To consider this variability, spatial databases were developed for agricultural land-use, relevant climatic parameters, and topographic data using geographic information systems (GIS). Analytical GIS functions of map algebra and map overlay were used to calculate regional crop ET for the Cache la Poudre Basin in Colorado. The Cache la Poudre Basin was selected as the study area due to the availability of ground truthed land-use survey data. This research uses land-use classification, climatic variables and elevation adjustments to determine the value of using a spatial/GIS approach instead of current nonspatial approaches.

A General Framework for a Collaborative Water Quality Knowledge and Information Network

Increasing knowledge about the environment has brought about a better understanding of the complexity of the issues, and more information publicly available has resulted into a steady shift from centralized decision making to increasing levels of participatory processes. The management of that information, in turn, is becoming more complex. One of the ways to deal with the complexity is the development of tools that would allow all players, including managers, researchers, educators, stakeholders and the civil society, to be able to contribute to the information system, in any level they are inclined to do so. In this project, a search for the available technology for collaboration, methods of community filtering, and community-based review was performed and the possible implementation of these tools to create a general framework for a collaborative “Water Quality Knowledge and Information Network” was evaluated. The main goals of the network are to advance water quality education and knowledge; encourage distribution and access to data; provide networking opportunities; allow public perceptions and concerns to be collected; promote exchange of ideas; and, give general, open, and free access to information. A reference implementation was made available online and received positive feedback from the community, which also suggested some possible improvements.

Decision Support System for Adaptive River Basin Management: Application to the Geum River Basin, Korea

Abstract The MODSIM 8.0 decision support system (DSS) for integrated river basin management (IRBM) has been adapted from a prior appropriation rights-based system to one found in Korea and in much of Asia where water deficits are shared among water use sectors, taking into account priorities established by water policy and institutional frameworks. The Korean version called KModSim is applied to the Geum River basin for evaluation of long-term sustainability of existing and new water infrastructure and facilities under integrated, basin-wide water resources management. KModSim is calibrated to the physical and hydrologic characteristics of the basin, as well as to operational and administrative water allocation policies for municipal and industrial water supply, irrigation, hydropower, transbasin diversions, and low-flow augmentation for environmental purposes. Conditional reservoir operational rules that adapt to changing river basin hydrologic conditions are developed from an implicit stochastic optimization algorithm and incorporated using the extensive user-customization capabilities of KModSim. Results demonstrate that decision guidance under KModSim enhances beneficial water uses in the Geum River system through fully integrated, basin-wide management.

Model for Reservoir Operations During Periods of High Flow

A combined dynamic programming optimization and hydraulic simulation model is presented for the analysis of the operation of hydroelectric reservoir facilities during periods of flood flows. The model is specifically designed to analyze the impacts of reservoir operations on upstream flooding and to consider complex reservoir outlet works. The model was applied to analyze the design and operational strategies for the Visegrad Hydroelectric Project in Yugoslavia. Results of the analysis indicated that the most economical means of flood protection for upstream areas was a combination of flood protection structures and a lowering of the reservoir storage level in anticipation of flood flows.

Data Consolidation from Hydroelectric Plants

This paper presents a sequence of procedures for data analysis and correction from hydroelectric plants. The procedures are based on variable data recorded by the plant. Therefore, they do not require additional financial investment in instrumentation for measurements. The proposed methodology makes use of a data manager, a queries builder, a generator of the overall efficiency function and an electronic spreadsheet. It has been applied to the data from a large Brazilian hydroelectric plant whose operation is under the coordination of the Electric System National Operator (ONS). The benefits of the data correction are analyzed using a simulator of the hydroelectric plants operation. This simulator is used to reproduce the past operation of the plant, once with official data and the next with adjusted data. The results show significant improvements in terms of quality of the data, contributing to the efficiency and reliability of the computational models in use by the energy sector in the operation planning.

Evaluation of Optimization Algorithms to Adjust Efficiency Curves for Hydroelectric Generating Units

AbstractThe power generated by a hydroelectric plant depends on the penstock head loss, the turbine efficiency, and the generator efficiency among other factors. Initially, the functions related to these variables are provided by the equipment manufacturer; however, over time they change as the plant ages. This paper presents a methodology to adjust an efficiency function for each generating unit based on measured data. It is applied using two optimization methods: the generalized reduced gradient and the evolutionary algorithm. A case study with data from a large Brazilian hydroelectric plant demonstrates how the methodology can be employed and compares the performance of the optimization tools. A comparison metric is used to show that the optimal unit efficiency function significantly improves the performance of simulation models to reproduce observed data and better describe the actual operation of the hydroelectric plant.

Efficiency Curves for Hydroelectric Generating Units

AbstractThis paper presents a methodology for obtaining and adjusting of efficiency curves for hydroelectric generating units. It is based on measured data of power, gross head, and water discharge recorded by the company that manages the plant operation. The objective is to determine the actual performance characteristics of the set: turbine, generator, and penstock. In order to obtain the efficiency functions, an iterative calculation is used. Its input data are the functions currently in use of turbine efficiency, generator efficiency, and penstock head losses. For the adjustment of the efficiency functions, the Generalized Reduced Gradient optimization method is employed. A case study was applied to the data from a large Brazilian hydroelectric plant whose operation is under the coordination of the Electric System National Operator. The benefits of the proposed methodology are analyzed using a simulation tool for the hydroelectric operation. The simulator is used to reproduce the past operation of the...