Report of a Workshop on Predictability and Limits-To-Prediction in Hydrologic Systems


Book Description

The Committee on Hydrologic Science (COHS) of the National Research Council (NRC) is engaged in studying the priorities and future strategies for hydrologic science. In order to involve a broad community representation, COHS is organizing workshops on priority topics in hydrologic science. These efforts will culminate in reports from the NRC on the individual workshops as well as a synthesis report on strategic directions in hydrologic science. The first workshop-Predictability and Limits-to-Prediction in Hydrologic Systems-was held at the National Center for Atmospheric Research in Boulder, Colorado, September 21-22, 2000. Fourteen technical presentations covered basic research and understanding, model formulations and behavior, observing strategies, and transition to operational predictions.




Review of the GAPP Science and Implementation Plan


Book Description

Water managers rely on predicting changes in the hydrologic cycle on seasonal-to-interannual time frames to prepare for water resource needs. Seasonal to interannual predictability of the hydrologic cycle is related to local and remote influences involving land processes and ocean processes, such as the El Niño Southern Oscillation. Although advances in understanding land-surface processes show promise in improving climate prediction, incorporating this information into water management decision processes remains a challenge since current models provide only limited information for predictions on seasonal and longer time scales. To address these needs, the Global Energy and Water Cycle Experiment (GEWEX) Americas Prediction Project (GAPP) was established in 2001 to improve how changes in water resources are predicted on intraseasonal-to-interannual time scales for the continental United States. The GAPP program has developed a science and implementation plan to guide its science activities, which describes strategies for improving prediction and decision support in the hydrologic sciences. This report by the National Research Council provides a review of the GAPP Science and Implementation Plan, outlining suggestions to strengthen the plan and the GAPP program overall.




Groundwater Fluxes Across Interfaces


Book Description

Estimates of groundwater recharge and discharge rates are needed at many different scales for many different purposes. These include such tasks as evaluating landslide risks, managing groundwater resources, locating nuclear waste repositories, and estimating global budgets of water and greenhouse gasses. Groundwater Fluxes Across Interfaces focuses on scientific challenges in (1) the spatial and temporal variability of recharge and discharge, (2) how information at one scale can be used at another, and (3) the effects of groundwater on climate and vice versa.




Distributed Hydrologic Modeling Using GIS


Book Description

1. 5 REFERENCES 127 7 DIGITAL TERRAIN 129 1. 1 INTRODUCTION 129 1. 2 DRAINAGE NETWORK 130 1. 3 DEFINITION OF CHANNEL NETWORKS 135 1. 4 RESOLUTION DEPENDENT EFFECTS 138 1. 5 CONSTRAINING DRAINAGE DIRECTION 141 1. 6 SUMMARY 145 1. 7 REFERENCES 146 8 PRECIPITATION MEASUREMENT 149 1. 1 INTRODUCTION 149 1. 2 RAIN GAUGE ESTIMATION OF RAINFALL 151 ADAR STIMATION OF RECIPITATION 1. 3 R E P 155 1. 4 WSR-88D RADAR CHARACTERISTICS 167 1. 5 INPUT FOR HYDROLOGIC MODELING 172 1. 6 SUMMARY 174 1. 7 REFERENCES 175 9 FINITE ELEMENT MODELING 177 1. 1 INTRODUCTION 177 1. 2 MATHEMATICAL FORMULATION 182 1. 3 SUMMARY 194 1. 4 REFERENCES 195 10 DISTRIBUTED MODEL CALIBRATION 197 1. 1 INTRODUCTION 197 1. 2 CALIBRATION APPROACH 199 1. 3 DISTRIBUTED MODEL CALIBRATION 201 1. 4 AUTOMATIC CALIBRATION 208 1. 5 SUMMARY 214 1. 6 REFERENCES 214 11 DISTRIBUTED HYDROLOGIC MODELING 217 1. 1 INTRODUCTION 218 1. 2 CASE STUDIES 218 1. 3 SUMMARY 236 1. 4 REFERENCES 237 12 HYDROLOGIC ANALYSIS AND PREDICTION 239 1. 1 INTRODUCTION 239 x Distributed Hydrologic Modeling Using GIS 1. 2 VFLOTM EDITIONS 241 1. 3 VFLOTM FEATURES AND MODULES 242 1. 4 MODEL FEATURE SUMMARY 245 1. 5 VFLOTM REAL-TIME 256 1. 6 DATA REQUIREMENTS 258 1. 7 RELATIONSHIP TO OTHER MODELS 259 1. 8 SUMMARY 260 1.




Flood Assessment


Book Description

About 7,000 people lose their lives and nearly 100 million people are adversely affected by floods each year worldwide. Flooding occurs in almost every part of the world and is the result of extreme rainfall. Severe flooding also costs billions of dollars each year in damage and economic losses. This new volume focuses on two detailed studies that employ physically based hydrologic models to predict flooding in the particularly challenging environment of small watersheds with mountainous terrain and high intensity/high variability rainfall.




Stochasticity, Nonlinearity and Forecasting of Streamflow Processes


Book Description

Streamflow forecasting is of great importance to water resources management and flood defense. On the other hand, a better understanding of the streamflow process is fundamental for improving the skill of streamflow forecasting. The methods for forecasting streamflows may fall into two general classes: process-driven methods and data-driven methods. Equivalently, methods for understanding streamflow processes may also be broken into two categories: physically-based methods and mathematically-based methods. This thesis focuses on using mathematically-based methods to analyze stochasticity and nonlinearity of streamflow processes based on univariate historic streamflow records, and presents data-driven models that are also mainly based on univariate streamflow time series. Six streamflow processes of five rivers in different geological regions are investigated for stochasticity and nonlinearity at several characteristic timescales.







Climate Science for Serving Society


Book Description

This volume offers a comprehensive survey and a close analysis of efforts to develop actionable climate information in support of vital decisions for climate adaptation, risk management and policy. Arising from submissions and discussion at the 2011 Open Science Conference (OSC) of the World Climate Research Program (WCRP), the book addresses research and intellectual challenges which span the full range of Program activities.




Hydrology, Ecology, and Fishes of the Klamath River Basin


Book Description

The Klamath River basin, which spans parts of southern Oregon and northern California, has been the focus of a prominent conflict over competing uses for water. Management actions to protect threatened and endangered fish species in the basin have left less water available for irrigation in dry years and heightened tensions among farmers and other stakeholders including commercial fishermen, Native Americans, conservationists, hunters, anglers, and hydropower producers. This National Research Council book assesses two recent studies that evaluate various aspects of flows in the Klamath basin: (1) the Instream Flow Phase II study (IFS), conducted by Utah State University, and (2) the Natural Flow of the Upper Klamath Basin study (NFS), conducted by the U.S. Bureau of Reclamation (USBR). The book concludes that both studies offer important new information but do not provide enough information for detailed management of flows in the Klamath River, and it offers many suggestions for improving the studies. The report recommends that a comprehensive analysis of the many individual studies of the Klamath river basin be conducted so that a big picture perspective of the entire basin and research and management needs can emerge.




Effective Groundwater Model Calibration


Book Description

Methods and guidelines for developing and using mathematical models Turn to Effective Groundwater Model Calibration for a set of methods and guidelines that can help produce more accurate and transparent mathematical models. The models can represent groundwater flow and transport and other natural and engineered systems. Use this book and its extensive exercises to learn methods to fully exploit the data on hand, maximize the model's potential, and troubleshoot any problems that arise. Use the methods to perform: Sensitivity analysis to evaluate the information content of data Data assessment to identify (a) existing measurements that dominate model development and predictions and (b) potential measurements likely to improve the reliability of predictions Calibration to develop models that are consistent with the data in an optimal manner Uncertainty evaluation to quantify and communicate errors in simulated results that are often used to make important societal decisions Most of the methods are based on linear and nonlinear regression theory. Fourteen guidelines show the reader how to use the methods advantageously in practical situations. Exercises focus on a groundwater flow system and management problem, enabling readers to apply all the methods presented in the text. The exercises can be completed using the material provided in the book, or as hands-on computer exercises using instructions and files available on the text's accompanying Web site. Throughout the book, the authors stress the need for valid statistical concepts and easily understood presentation methods required to achieve well-tested, transparent models. Most of the examples and all of the exercises focus on simulating groundwater systems; other examples come from surface-water hydrology and geophysics. The methods and guidelines in the text are broadly applicable and can be used by students, researchers, and engineers to simulate many kinds systems.