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Evaluation of power function approximation of NEXRAD and rain gauge based precipitation estimates
Title
Evaluation of power function approximation of NEXRAD and rain gauge based precipitation estimates.
Creator
Mayes-Fernandez, Mario., College of Engineering and Computer Science, Department of Civil, Environmental and Geomatics Engineering
Abstract/Description
Radar rainfall estimates have become a decision making tool for scientists, engineers and water managers in their tasks for developing hydrologic models, water supply planning, restoration of ecosystems, and flood control. In the present study, the utility of a power function for linking the rain gauge and radar estimates has been assessed. Mean daily rainfall data from 163 rain gauges installed within the South Florida Water Management District network have been used and their records from...
Show moreRadar rainfall estimates have become a decision making tool for scientists, engineers and water managers in their tasks for developing hydrologic models, water supply planning, restoration of ecosystems, and flood control. In the present study, the utility of a power function for linking the rain gauge and radar estimates has been assessed. Mean daily rainfall data from 163 rain gauges installed within the South Florida Water Management District network have been used and their records from January 1st, 2002 to October 31st, 2007 analyzed. Results indicate that the power function coefficients and exponents obtained by using a non-linear optimization formulation, show spatial variability mostly affected by type of rainfall events occurring in the dry or wet seasons, and that the linear distance from the radar location to the rain gauge has a significant effect on the computed values of the coefficients and exponents.
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Date Issued
2009
PURL
http://purl.flvc.org/FAU/367761
Subject Headings
Radar meteorology, Technological innovations, Weather forecasting, Technological innovations, Precipitation (Meteorology), Measurement, Weather control, Mathematical models
Format
Document (PDF)
Development of functional relationships between radar and rain gage data using inductive modeling techniques
Title
Development of functional relationships between radar and rain gage data using inductive modeling techniques.
Creator
Peters, Delroy., College of Engineering and Computer Science, Department of Civil, Environmental and Geomatics Engineering
Abstract/Description
Traditional methods such as distance weighing, correlation and data driven methods have been used in the estimation of missing precipitation data. Also common is the use of radar (NEXRAD) data to provide better spatial distribution of precipitation as well as infilling missing rain gage data. Conventional regression models are often used to capture highly variant nonlinear spatial and temporal relationships between NEXRAD and rain gage data. This study aims to understand and model the...
Show moreTraditional methods such as distance weighing, correlation and data driven methods have been used in the estimation of missing precipitation data. Also common is the use of radar (NEXRAD) data to provide better spatial distribution of precipitation as well as infilling missing rain gage data. Conventional regression models are often used to capture highly variant nonlinear spatial and temporal relationships between NEXRAD and rain gage data. This study aims to understand and model the relationships between radar (NEXRAD) estimated rainfall data and the data measured by conventional rain gages. The study is also an investigation into the use of emerging computational data modeling (inductive) techniques and mathematical programming formulations to develop new optimal functional approximations. Radar based rainfall data and rain gage data are analyzed to understand the spatio-temporal associations, as well as the effect of changes in the length or availability of data on the models. The upper and lower Kissimmee basins of south Florida form the test-bed to evaluate the proposed and developed approaches and also to check the validity and operational applicability of these functional relationships among NEXRAD and rain gage data for infilling of missing data.
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Date Issued
2008
PURL
http://purl.flvc.org/FAU/166454
Subject Headings
Weather control, Mathematical models, Radar meteorology, Technological innovations, Precipitation (Meteorology), Measurement, Weather forecasting, Technological innovations
Format
Document (PDF)
Evaluation of optimal real-time reflectivity-rainfall rate (Z-R) functional relationships
Title
Evaluation of optimal real-time reflectivity-rainfall rate (Z-R) functional relationships.
Creator
Pattani, Kandarp., College of Engineering and Computer Science, Department of Civil, Environmental and Geomatics Engineering
Abstract/Description
Accuracy in estimation of precipitation can be achieved by utilizing the combination of spatial radar reflectivity data (Z) and the high resolution temporal rain gage based rainfall data (R). The study proposes the use of optimization models for optimizing the Z-R coefficients and exponents for different storm types and seasons. Precipitation data based on reflectivity, collected from National Climatic Data Center (NCDC) and rain gage data from Southwest Florida Water Management District ...
Show moreAccuracy in estimation of precipitation can be achieved by utilizing the combination of spatial radar reflectivity data (Z) and the high resolution temporal rain gage based rainfall data (R). The study proposes the use of optimization models for optimizing the Z-R coefficients and exponents for different storm types and seasons. Precipitation data based on reflectivity, collected from National Climatic Data Center (NCDC) and rain gage data from Southwest Florida Water Management District (SWFWMD) over same temporal resolutions were analyzed using the Rain-Radar- Retrieval (R3) system developed as a part of the study. Optimization formulations are proposed to obtain optimal coefficients and exponents in the Z-R relationships for different seasons and objective selection of storm-type specific Z-R relationships. Different approaches in selection of rain gage stations and selection of events for optimization are proposed using gradient based solver and genetic algorithms.
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Date Issued
2010
PURL
http://purl.flvc.org/FAU/2978946
Subject Headings
Precipitation (Meteorology), Measurement, Rain and rainfall, Measurement, Reflectance, Rainfall intensity duration frequencies
Format
Document (PDF)
Developing a Relationship between NEXRAD Generated Rainfall Values and Rain Gauge Measurements in South Florida
Title
Developing a Relationship between NEXRAD Generated Rainfall Values and Rain Gauge Measurements in South Florida.
Creator
Skinner, Courtney L., Bloetscher, Frederick, Florida Atlantic University, College of Engineering and Computer Science, Department of Civil, Environmental and Geomatics Engineering
Abstract/Description
The South Florida Water Management District (SFWMD) is an agency which relies on a network of nearly 300 rain gauges in order to provide rainfall data for use in operations, modeling, water supply planning, and environmental projects. However, the prevalence of convective and tropical rain events in South Florida during the wet season presents a challenge in that the current rain gauge network may not fully capture rainfall demonstrating high spatial variability. NEXRAD (Next Generation Radar...
Show moreThe South Florida Water Management District (SFWMD) is an agency which relies on a network of nearly 300 rain gauges in order to provide rainfall data for use in operations, modeling, water supply planning, and environmental projects. However, the prevalence of convective and tropical rain events in South Florida during the wet season presents a challenge in that the current rain gauge network may not fully capture rainfall demonstrating high spatial variability. NEXRAD (Next Generation Radar) technology offers water management officials the advantage of providing a spatial account of rainfall, although the relative quality of radar rainfall measurements remains largely unknown. The intent of this study is to examine the relationship between gauge-adjusted NEXRAD data and corresponding rain gauge measurements in order to assess the relative performance of radar and rain gauge technologies for a variety of different conditions.
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Date Issued
2006
PURL
http://purl.flvc.org/fau/fd/FA00012554
Subject Headings
Storms--United States--Florida, Radar meteorology, Precipitation (Meteorology)--Measurement, Rain and rainfall--Measurement
Format
Document (PDF)
Influences of decadal and multi-decadal oscillations on regional precipitation extremes and characteristics
Title
Influences of decadal and multi-decadal oscillations on regional precipitation extremes and characteristics.
Creator
Pierce, Milla, Teegavarapu, Ramesh, College of Engineering and Computer Science, Department of Civil, Environmental and Geomatics Engineering
Abstract/Description
Three major teleconnections, Atlantic Multidecadal Oscillation (AMO), North Atlantic Oscillation (NAO), and the Pacific Decadal Oscillation (PDO), in warm and cool phases, effect precipitation in Florida. The effects of the oscillation phases on the precipitation characteristics are analyzed by using long-term daily precipitation data, on different temporal (annual, monthly, and daily) and spatial scales, utilizing numerous indices, and techniques. Long-term extreme precipitation data for 9...
Show moreThree major teleconnections, Atlantic Multidecadal Oscillation (AMO), North Atlantic Oscillation (NAO), and the Pacific Decadal Oscillation (PDO), in warm and cool phases, effect precipitation in Florida. The effects of the oscillation phases on the precipitation characteristics are analyzed by using long-term daily precipitation data, on different temporal (annual, monthly, and daily) and spatial scales, utilizing numerous indices, and techniques. Long-term extreme precipitation data for 9 different durations is used to examine the effects of the oscillation phases on the rainfall extremes, by employing different parametric and non-parametric statistical tests, along with Depth-Duration- Frequency analysis. Results show that Florida will experience higher rainfall when AMO is in the warm phase, except in the panhandle and south Florida, while PDO cool phase is positively correlated with precipitation, except for the southern part of the peninsula.
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Date Issued
2013
PURL
http://purl.flvc.org/fau/fd/FA0004046
Subject Headings
Climatic change -- Environmental aspects, Climatic extremes, Hydrologic models, Hydrometeorology, Precipitation (Meteorology) -- Measurement
Format
Document (PDF)
Influences of climate variability and change on precipitation characteristics and extremes
Title
Influences of climate variability and change on precipitation characteristics and extremes.
Creator
Goly, Aneesh, College of Engineering and Computer Science, Department of Civil, Environmental and Geomatics Engineering
Abstract/Description
This study focuses on two main broad areas of active research on climate: climate variability and climate change and their implications on regional precipitation characteristics. All the analysis is carried out for a climate change-sensitive region, the state of Florida, USA. The focus of the climate variability analysis is to evaluate the influence of individual and coupled phases (cool and warm) of Atlantic multidecadal oscillation (AMO) and El Niäno southern oscillation (ENSO) on regional...
Show moreThis study focuses on two main broad areas of active research on climate: climate variability and climate change and their implications on regional precipitation characteristics. All the analysis is carried out for a climate change-sensitive region, the state of Florida, USA. The focus of the climate variability analysis is to evaluate the influence of individual and coupled phases (cool and warm) of Atlantic multidecadal oscillation (AMO) and El Niäno southern oscillation (ENSO) on regional precipitation characteristics. The two oscillations in cool and warm phases modulate each other which have implications on flood control and water supply in the region. Extreme precipitation indices, temporal distribution of rainfall within extreme storm events, dry and wet spell transitions and antecedent conditions preceding extremes are evaluated. Kernel density estimates using Gaussian kernel for distribution-free comparative analysis and bootstrap sampling-based confidence intervals are used to compare warm and cool phases of different lengths. Depth-duration-frequency (DDF) curves are also developed using generalized extreme value (GEV) distributions characterizing the extremes. ... This study also introduces new approaches to optimally select the predictor variables which help in modeling regional precipitation and further provides a mechanism to select an optimum spatial resolution to downscale the precipitation projections. New methods for correcting the biases in monthly downscaled precipitation projections are proposed, developed and evaluated in this study. The methods include bias corrections in an optimization framework using various objective functions, hybrid methods based on universal function approximation and new variants.
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Date Issued
2013
PURL
http://purl.flvc.org/fcla/dt/3362383
Subject Headings
Climatic changes, Environmental aspects, Global temperature changes, Environmental aspects, Precipitation (Meteorology), Measurement, Bootstrap (Statistics)
Format
Document (PDF)