Download or read book Real time Modeling of River Basin Response Using Radar generated Rainfall Maps and a Distributed Hydrologic Database written by Luis Garrote and published by . This book was released on 1993 with total page 404 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Estimation of Rainfall for Flood Forecasting Using Radar and Rain Gage Data written by William J. Charley and published by . This book was released on 1988 with total page 14 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Runoff Simulation Using Radar Rainfall Data written by John Charles Peters and published by . This book was released on 1996 with total page 20 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Technical Report written by Massachusetts Institute of Technology. Hydrodynamics Laboratory and published by . This book was released on 1993 with total page 422 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Environmental Systems written by Antonio S. Camara and published by Oxford University Press, USA. This book was released on 2002 with total page 346 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is intended for scholars and students of geography, geology, environmental science, civil engineering, urban planning biology, and social sciences.
Download or read book Hydrological Forecasting with Radar and the Probability Distributed Hydrological Model PDM written by Gbotemi Abraham Adediran and published by Universal-Publishers. This book was released on 2015-07-01 with total page 112 pages. Available in PDF, EPUB and Kindle. Book excerpt: The efficiency of a probabilistic hydrological forecasting system with weather radar and the Probability distributed hydrological model (PDM) was evaluated at the Brue catchment; south-western England. The ability of the radar to measure gauged precipitation in 2007 (regarded as the ground truth) was evaluated using Normalized Bias (NB) and Normalized Error (NE) statistics as the objective function of evaluation. The radar overestimated precipitation measurements by average gauges with NB value of 0.41 and a considerably low NE of 0.68. Furthermore, the effectiveness of a Deterministic nowcasting system (DNS) to forecast radar measured precipitation at 132 forecast time series of 6hrs forecast lead time was assessed. The DNS overestimated the radar measured precipitation with a NB value of 87% and recorded an accumulated NE of 146%. Moreover, the efficiencies of 10 ensemble precipitation forecats generated from a Stochastic nowcasting system (SNS) over the singular deterministic forecasts from the DNS was evaluated at 3 major hydrological events. Some of the ensembles significantly performed better than the deterministic forecast and brilliantly captured the radar measured precipitation at most of the forecast time series. Furthermore, the efficiencies of these sources of precipitation measurement to simulate flows with the PDM at the Brue catchment were also assessed by integrating the radar-based forecasts with measurements from average gauges. The PDM performed satisfactorily well in simulating the flows of 17th January 2007 with an average Nash–Sutcliffe Efficiency Index (NSE) of 0.65 and the model was judged insensitive to the significantly high precipitation inputs for the hydrological event of 27th of May 2007. However, the PDM performed poorly in simulating flows for the historical storms of 20th of July 2007; with the model under estimating flows with bias value of over 250 cumecs for an event popular for its devastating flooding in the Southwest of England. The model inadequacies was however associated to poor radar precipitation measurements and forecasts on which flow simulation was based. This work therefore emphasis the need for developments in hydrological modeling as well as advancement in weather radar technology to effectively correct radar errors due to radar calibration, signal attenuation, clutter and anomalous propagation, vertical variation of reflectivity, range effects, Z-R relationships, variations of drop size distributions, vertical air motions, beam overshooting the shallow precipitation and sampling issues, that has been identified to affect radar measurements.
Download or read book A Pilot Application of Weather Radar based Runoff Forecasting Salt River Basin MO written by and published by . This book was released on 1996 with total page 48 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Hydrologic Validation of Real Time Weather Radar VPR Correction Methods written by Erika Suzanne Klyszejko and published by . This book was released on 2007 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book China written by World Bank and published by World Bank Publications. This book was released on 1993 with total page 1422 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Republic of Korea's industrial policy has directed that nation's economy through nearly three decades of spectacular growth. But the authors of this paper maintain that this policy is showing signs of being outmoded. The time has come, the authors argue, for the Korean government to stop managing the economy's structural development and to redefine the responsibilities of business and government. Under this proposed compact, the allocation of resources would shift from the government to the private industrial and financial sectors. The transformation of the government bureaucracy from an ad hoc policy role to one of a transparent and predictable regulator is a key to the success of this undertaking. These new directions would present the government with enormous challenges. Greater competitive discipline and regulatory oversight would be required. While dealing with the complexities of the transition, the government would have to maintain macroeconomic stability and the momentum of savings and investment. For comparison, the study examines the industrial economies of France, Germany, Japan, and the United States, which underwent similar shifts.
Download or read book Near Real time Runoff Estimation Using Spatially Distributed Radar Rainfall Data written by Jennifer Lyn Hadley and published by . This book was released on 2004 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The purpose of this study was to evaluate variations of the Natural Resources Conservation Service (NRCS) curve number (CN) method for estimating near real-time runoff for naturalized flow, using high resolution radar rainfall data for watersheds in various agro-climatic regions of Texas. The CN method is an empirical method for calculating surface runoff which has been tested on various systems over a period of several years. Many of the findings of previous studies indicate the need to develop variations of this method to account for regional and seasonal changes in weather patterns and land cover that might affect runoff. This study seeks to address these issues, as well as the inherent spatial variability of rainfall, in order to develop a means of predicting runoff in near real-time for water resource management. In the past, raingauge networks have provided data for hydrologic models. However, these networks are generally unable to provide data in real-time or capture the spatial variability associated with rainfall. Radar networks, such as the Next Generation Weather Radar (NEXRAD) of the National Weather Service (NWS), which are widely available and continue to improve in quality and resolution, can accomplish these tasks. In general, a statistical comparison of the raingauge and NEXRAD data, where both were available, shows that the radar data is as representative of observed rainfall as raingauge data. In this study, watersheds of mostly homogenous land cover and naturalized flow were used as study areas. Findings indicate that the use of a dry antecedent moisture condition CN value and an initial abstraction (Ia) coefficient of 0.1 produced statistically significant results for eight out of the ten watersheds tested. The urban watershed used in this study produced more significant results with the use of the traditional 0.2 Ia coefficient. The predicted results before and during the growing season, in general, more closely agreed with the observed runoff than those after the growing season. The overall results can be further improved by altering the CN values to account for seasonal vegetation changes, conducting field verification of land cover condition, and using bias-corrected NEXRAD rainfall data.
Download or read book Rainfall Runoff Modelling written by Keith J. Beven and published by John Wiley & Sons. This book was released on 2003 with total page 384 pages. Available in PDF, EPUB and Kindle. Book excerpt: Amid climatic changes linked to global warming, ongoing changes in land-use patterns, and growing international concern with the environment it is increasingly important to understand the potential impact of these changes on the environment. Rainfall-runoff modeling is an important predictor of that impact. This book introduces rainfall-runoff models that have been developed over the past 24-30 years, giving examples of their practical applications. It provides a summary of available techniques for rainfall modeling based upon the most recent research, but in a way that serves as a primer for the subject. Provides an overview of how catchment rainfall-runoff systems work A history of rainfall-runoff models Examples of models can be downloaded over the Internet Looks at uncertainty in model prediction
Download or read book Government Reports Announcements Index written by and published by . This book was released on 1993 with total page 1030 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Application of Rainfall runoff Simulation for Flood Forecasting written by John Peters and published by . This book was released on 1993 with total page 24 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Evaluation of Gauge radar Merging Methods for Quantitative Precipitation Estimation in Hydrology written by Jack L. McKee and published by . This book was released on 2015 with total page 270 pages. Available in PDF, EPUB and Kindle. Book excerpt: Hydrological models rely on accurate precipitation data in order to produce results with a high degree of confidence and serve as valuable flood forecasting and warning tools. Gauge-radar merging methods combine rainfall estimates from rain gauges and weather radar in order to capitalize on the strengths of the individual instruments and produce precipitation data with greater accuracy for input to hydrological models. A comprehensive review of gauge-radar merging methods reveals that there is an opportunity for near-real time application in hydrological models. The performance of four well known gauge-radar merging methods, including mean field bias correction, Brandes spatial adjustment, local bias correction using kriging and conditional merging, are examined using Environment Canada radar and the Upper Thames River basin in southwestern Ontario, Canada, as a case study. The analysis assesses the effect of gauge-radar merging methods on: 1) the accuracy of predicted rainfall accumulations; and 2) the accuracy of predicted stream flows using a semi-distributed hydrological model. In addition, several influencing factors (i.e., gauge density, storm type, basin type, proximity to the radar tower and time-step of adjustment) are analysed to determine their effect on the performance of the rainfall estimation techniques. Results indicate that gauge-radar merging methods can increase the accuracy of both rainfall accumulation estimations and predicted stream flows over the use of raw radar and rain gauges alone. Results from this study provide guidance for hydrologists and engineers assessing whether the addition of corrected radar products will improve rainfall estimation and hydrological modelling accuracy.
Download or read book Improvements in Flood Forecasting in Mountain Basins Through a Physically based Distributed Model written by Hernan Moreno Ramirez and published by . This book was released on 2012 with total page 195 pages. Available in PDF, EPUB and Kindle. Book excerpt: This doctoral thesis investigates the predictability characteristics of floods and flash floods by coupling high resolution precipitation products to a distributed hydrologic model. The research hypotheses are tested at multiple watersheds in the Colorado Front Range (CFR) undergoing warm-season precipitation. Rainfall error structures are expected to propagate into hydrologic simulations with added uncertainties by model parameters and initial conditions. Specifically, the following science questions are addressed: (1) What is the utility of Quantitative Precipitation Estimates (QPE) for high resolution hydrologic forecasts in mountain watersheds of the CFR?, (2) How does the rainfall-reflectivity relation determine the magnitude of errors when radar observations are used for flood forecasts?, and (3) What are the spatiotemporal limits of flood forecasting in mountain basins when radar nowcasts are used into a distributed hydrological model?. The methodology consists of QPE evaluations at the site (i.e., rain gauge location), basin-average and regional scales, and Quantitative Precipitation Forecasts (QPF) assessment through regional grid-to-grid verification techniques and ensemble basin-averaged time series. The corresponding hydrologic responses that include outlet discharges, distributed runoff maps, and streamflow time series at internal channel locations, are used in light of observed and/or reference data to diagnose the suitability of fusing precipitation forecasts into a distributed model operating at multiple catchments. Results reveal that radar and multisensor QPEs lead to an improved hydrologic performance compared to simulations driven with rain gauge data only. In addition, hydrologic performances attained by satellite products preserve the fundamental properties of basin responses, including a simple scaling relation between the relative spatial variability of runoff and its magnitude. Overall, the spatial variations contained in gridded QPEs add value for warm-season flood forecasting in mountain basins, with sparse data even if those products contain some biases. These results are encouraging and open new avenues for forecasting in regions with limited access and sparse observations. Regional comparisons of different reflectivity -rainfall (Z-R) relations during three summer seasons, illustrated significant rainfall variability across the region. Consistently, hydrologic errors introduced by the distinct Z-R relations, are significant and proportional (in the log-log space) to errors in precipitation estimations and stream flow magnitude. The use of operational Z-R relations without prior calibration may lead to wrong estimation of precipitation, runoff magnitude and increased flood forecasting errors. This suggests that site-specific Z-R relations, prior to forecasting procedures, are desirable in complex terrain regions. Nowcasting experiments show the limits of flood forecasting and its dependence functions of lead time and basin scale. Across the majority of the basins, flood forecasting skill decays with lead time, but the functional relation depends on the interactions between watershed properties and rainfall characteristics. Both precipitation and flood forecasting skills are noticeably reduced for lead times greater than 30 minutes. Scale dependence of hydrologic forecasting errors demonstrates reduced predictability at intermediate-size basins, the typical scale of convective storm systems. Overall, the fusion of high resolution radar nowcasts and the convenient parallel capabilities of the distributed hydrologic model provide an efficient framework for generating accurate real-time flood forecasts suitable for operational environments.
Download or read book River Basin Modelling for Flood Risk Mitigation written by Donald Knight and published by CRC Press. This book was released on 2005-11-17 with total page 626 pages. Available in PDF, EPUB and Kindle. Book excerpt: Flooding accounts for one-third of natural disasters worldwide and for over half the deaths which occur as a result of natural disasters. As the frequency and volume of flooding increases, as a result of climate change, there is a new urgency amongst researchers and professionals working in flood risk management. River Basin Modelling for Flood Risk Mitigation brings together thirty edited papers by leading experts who gathered for the European Union’s Advanced Study Course at the University of Birmingham, UK. The scope of the course ranged from issues concerning the protection of life, to river restoration and wetland management. A variety of topics is covered in the book including climate change, hydro-informatics, hydro-meterology, river flow forecasting systems and dam-break modelling. The approach is broad, but integrated, providing an attractive and informative package that will satisfy researchers and professionals, while offering a sound introduction to students in Engineering and Geography.
Download or read book The Estimation of Rainfall for Flood Forecasting Using Radar and Rain Gage Data written by and published by . This book was released on 1988 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: An inadequate knowledge of the magnitude and spatial distribution of precipitation is often a major limitation in developing accurate river-flow forecasts for use in reservoir operations Digitized weather radar data can provide useful information regarding the spatial distribution of rainfall, although radar-based estimates of rainfall may be in error due to several factors. The use of radar-rainfall data in combination with rain gage measurements may improve rainfall estimates over those based on either form of measurement alone. This improvement is accomplished by adjusting, or 'calibrating', radar-rainfall data with data from rain gages situated within the radar 'boundary'. A set of rainfall analysis software that incorporates this methodology has been developed by the U.S. Army Corps of Engineers Hydrologic Engineering Center to aid hydrologists in making real-time water control decisions. The rainfall-analysis software retrieves real-time radar-rainfall data from a National Weather Service RADAP II (Radar Data Processor), and rain gage measurements from data collection platforms via the Geostationary Operational Environmental Satellite (GOES). The radar data from the RADAP II is 'calibrated' with the rain gage data using a simple Kriging technique. Subbasin-average rainfall is then computed from the calibrated data and stored in a data base file subsequent use by a river-flow forecast model. Graphics programs aid in the evaluation of the data. This software system has been implemented for a few pilot watersheds in Oklahoma. (FR).
