aggregation, 5artificial neural networks (ANNs), 97, 100-101backscatter, 33-35beam blockage, 17, 19, 19fbelow-beam effects, 17, 18fbias analysis methods: background of, 73-74; categories of, 76-78, 77f; detailed description of, 77-84, 78t, 79f-84f; ideal performance measures and skill scores and, 84, 85t, 86t; indexes based on metrics and, 75-76; rain gauges and, 76; types of, 75; utility assessment indexes and performance measures and, 85, 87t, 88-89bias assessment tool, 79, 79fbias corrections: background on, 89; with limited rain-gauge data, 90; temporal resolution issues and, 90-91bright bands, 18Climate Data Online (CDO), 7, 8climatology-calibrated precipitation analysis, 47-48correlation weighting techniques, 97data replacement tests, 106-107, 106fdepth area adjustment factors (DARFs), 28depth area reduction factors, 66deterministic weighting, 95-96; missing data estimation and, 96-98digital hybrid reflexivity field (DHR), 40digital precipitation array (DPA), 40, 42digital storm total precipitation (DSP), 40, 42distributed models, 6-7Doppler radar, 4-5dual polarization, 27elevated radar sites, 17equal weights method, 105error distribution, of radar rainfall estimates, 40-41gauge-adjusted radar rainfall estimation (GARR), 20-21, 27-28, 60-62gauge-radar adjustment: approaches to, 45-47, 46f; local bias correction, 43; mean-field bias correction, 41-42; quality control and, 73gauge-radar observation merging, 43-45gauge-radar pair (GRP), 42geographically weighted optimization (GWO), 101-102, 102fgeospatial grid-based transformations, 102-105, 104fgridded multi-radar products, 48-49ground clutter, 17, 19groundwater recharge modeling, 68Hydrologic Rainfall Analysis Project grid (HRAP grid), 14-15, 15f, 23HEC-METVUE (Meteorological Visualization Utility Engine), 21-22Hurricane Dennis (2005), 45, 46fhybrid scan discontinuity, 18hydrologic model evaluation, 75hydrologic modeling: calibration of, 60-61; data requirements for, 59-60, 60f; radar rainfall data for, 60-62hydrometeor identification, 37-38infilling rainfall data: issues related to, 105-107, 106f; radar data use and, 98-102, 101f, 102finverse distance weighting method (IDWM), 3, 96, 97Journal of Hydrologic Engineering, 1-2kriging technique, 3local bias correction, 43Louisville Jefferson County Metropolitan Sewer District (Louisville, KY), 24maximum area method, 104mean-field bias (MFB), 41-42; evaluation of, 73, 77meteorologically homogeneous rainfall areas, 118-119, 119fmultisensor precipitation estimator data (MPE data), 7-8, 23multi-sensor products, 48-49National Centers for Environmental Information (NCEI), 7National Weather Service (NWS), 8, 23, 27native radar data resolution, 11-12, 12fNCDC Weather and Climate Toolkit, 11-12near-real-time flood warning system, 67NEXRAD program, 3-4, 8, 15, 26NOAA Central Library of US Daily Weather Maps, 8NOAA (National Oceanic and Atmospheric Administration), 3, 27optimal density, 113optimal Z-R relationships, 54-57overhead “blind” spots, 18phased array system, 27precipitation observations, access to, 48-49PRISM climate group, 7PRISM Climate Group, 8probable maximum precipitation (PMP) estimation, 24-25quality control, gauge-adjustment procedures and, 73quantile-quantile plot (Q-Q plot), 82quantitative precipitation estimates (QPE): daily precipitation reports and, 47-48; function of, 31, 45, 47 (See also radar rainfall data processing)radar beam issues, 17, 17f, 18f, 19, 19fradar coverage limit discontinuity, 18, 19radar data: anomalies in, 17-19, 18f-20f; optimal network design using, 116-118, 117f; used for infilling rainfall data, 98-102, 101f, 102fradar data acquisition (RDA) subsystem, 33, 34fradar precipitation products, 33radar product generator (RPG), 33, 34f, 41radar quality control, 35, 36f, 37, 40radar rainfall data: archived, 27; availability in United States of, 7-8, 8f; data formats and resolutions of, 13-16, 15f, 16f; dual polarization and, 27; geospatial grid-based transformations of, 102-105, 104f; hydrologic modeling and, 59-62; native resolution of, 11-12, 12f; optimal Z-R relationships and, 54-57; phased array and, 27; QA/QC and data management and, 16-20, 17f-21f; radar mosaics and, 12-13, 13f, 14f; rainfall measurement methods and, 53; rain-gauge and radar based measurements and, 53-54; scientific formats for gridding, 13-14radar rainfall data analysis: depth area reduction factors and, 66; function of, 21-22; rainfall frequency analysis and, 65-66Radar Rainfall Data and Application Task Committee [Watershed Council of the Environmental and Water Resources Institute (EWRI)], 2radar rainfall data applications, 66; groundwater recharge modeling, 68; near-real-time flood warning system, 67; rain-gauge network design, 68-69; sewer system modeling, 67-68radar rainfall data evaluation/improvement: optimal Z-R relationships and, 54-57; rainfall measurement methods and, 53; rain-gauge and radar based measurements and, 53-54radar rainfall data processing: access to precipitation observations and estimates and, 48-49; applicability of gauge-radar approaches and, 45-47; background related to, 31-32; daily precipitation reports used with radar QPE and, 47-48; error distribution of estimates and, 40-41; gauge-radar adjustment and, 41-43, 41e, 42e; gauge-radar observation merging and, 43-45, 46f; hydrometeor identification and, 37-38; radar QPE products and, 40; radar quality control and, 35, 36f, 37; reflectivity-precipitation rate relationships and, 38-39, 39f; single-polarization radar precipitation estimates and, 33-35, 34f; stages in, 33radar rainfall data use: missing data from rain gauges and, 26; probable maximum precipitation estimation as, 24-25; real-time hydrologic monitoring, flood forecasting and disaster management as, 23-24, 23f-25fradar rainfall estimates: background of, 3-4; conclusions related to, 27-28; critical issues and limitations associated with, 88-89; derived from conversion of reflexivity, 73; error distribution of, 40-41; function of, 4-7; gauge-adjusted, 20-21; overview of, 1-2rainfall data: missing data estimation and, 96-98; spatial and temporal analysis of, 95-96rainfall estimation: background of, 1; radar, 1-7; references for, 8; traditional, 2-3, 3f, 4frainfall frequency analysis, 65-66rainfall interpolation techniques, 3, 4frainfall monitoring networks: description of, 111; meteorological homogeneous areas identification and, 118-119, 119f; network design and, 113; optimal density and monitoring networks and, 113; optimal network design and, 114-116; optimal rain-gauge monitoring networks and, 112-113; post-network design recommendations and, 118; radar data and, 116-118, 117f; rain-gauge network density and, 111-112, 112trainfall transformation process, 59, 60frain-gauge networks. See also rainfall monitoring networks: density of, 111-112, 112t; design of, 68-69rain-gauges. See also rainfall monitoring networks: measurement of, 2-3, 3f; missing data estimation and, 26; placement of, 118; reports on, 49range fade, 19real-time hydrologic monitoring, flood forecasting and disaster management, 23-24, 23f-25freflectivity-precipitation rate relationships, 38-39, 39freflectivity-to-rain rate (Z-R) equations, 38replacement tests, 106-107, 106fRice University and Texas Medical Center (Houston, TX), 24River Forecast Center (RFC) (NWS), 7, 8fsewer system modeling, 67-68single-polarization radar precipitation estimates, 33-35, 34f, 37, 38South Florida Water Management District (SFWMD), 24, 25f, 65, 68, 69, 114, 115; radar rainfall estimation in, 63-65spatial analysis: issues related to, 95-96; missing data estimation and, 96-98spatial domain filters, 103spatial weighting method, 103standard hydrologic grid (SHG), 14-16, 16fTaylor’s diagram, 80, 80f, 81ftemporal analysis, issues related to, 95-96Terminal Doppler Weather Radar (TDWR), 31Thiessen polygon technique, 3, 4f, 97University Corporation for Atmospheric Research (UCAR), 48-49USACE HEC, 21-22US Army Corps of Engineers (USACE), 14, 15, 23, 27utility assessment indexes, 85, 87t, 88-89Vance Air Force Base (AFB) radar, 26variable density analysis block approach, 116-117, 117fWeather Service Radar Doppler (WSR-88D), 31-33, 34f, 61
