Papers by Sandra Cruz-pol
WSEAS Transactions …, 2008
Validation of the Hydro-Estimator (HE) and the Next Generation Radar (NEXRAD) during heavy storms... more Validation of the Hydro-Estimator (HE) and the Next Generation Radar (NEXRAD) during heavy storms over Puerto Rico (PR) is reported. The HE is a high resolution rainfall retrieval algorithm based on satellite and numerical weather prediction model data. The accuracy of the HE ...
Flood alert system using rainfall forecast data in Western Puerto Rico
2013 IEEE International Geoscience and Remote Sensing Symposium - IGARSS, 2013
ABSTRACT The Western Puerto Rico area is subject to flooding due to sudden, extreme rainfall even... more ABSTRACT The Western Puerto Rico area is subject to flooding due to sudden, extreme rainfall events, some of which fail to be detected by NOAA's NEXRAD radar. The use of new radars with higher spatial resolution and covering the low atmosphere are vital for flood forecasting efforts, and for studying and predicting atmospheric phenomena. Recently the University of Puerto Rico in Mayagüez initiated investigations using two (2) types of these radars, Off-the Grid (OTG) and TropiNet (RXM-25), respectively, in the Mayagüez Bay Drainage Basin area. This is the first time that such radar technology will be used for hydrologic analyses and specifically for rainfall forecasting in Puerto Rico. The forecast analysis will be made using time series with autoregressive methods and selecting the stochastic model parameters most appropriate for an optimal prediction; with the radar results, a distributed hydrologic model (Vflo™) is used to obtain the spatial distribution of flooding depth.
Proceedings of the 12th Wseas International Conference on Systems, Jul 22, 2008
Validation of the Hydro-Estimator (HE) and the Next Generation Radar (NEXRAD) during heavy storms... more Validation of the Hydro-Estimator (HE) and the Next Generation Radar (NEXRAD) during heavy storms over Puerto Rico (PR) is reported. The HE is a high resolution rainfall retrieval algorithm based on satellite and numerical whether prediction model data. The accuracy of the HE and the NEXRAD rainfall estimates can be measured by decomposing the rainfall process in sequences of discrete (rain / no rain) and continuous (rainfall rate) random variables. Validation results are based on five heavy storms that seriously impacted human life and the economy of PR during the period 2003 to 2005. The average discrete validation results indicate acceptable hit rate values for both the HE and NEXRAD (0.76 vs. 0.87) and reasonable discrete bias ratios (1.04 vs. 0.73) but a very low of probability of detection of rain for both the HE and NEXRAD (0.36 vs. 0.52). The HE shows an average overestimation whereas the NEXRAD exhibits underestimation in the continuous validation results (continuous bias ratio of 1.14 vs 0.70 for NEXRAD), which contributes to moderate overall errors for the HE and NEXRAD in terms of root mean squared error (2.14 mm vs. 1.66 mm) and mean absolute error (0.96 mm vs. 0.77 mm).
Radares CASA_
utilizando cuatro radares o nodos, cuya localización fue seleccionada estratégicamente para cubri... more utilizando cuatro radares o nodos, cuya localización fue seleccionada estratégicamente para cubrir esta área [Ríos-Olmo,2009, MS Tesis]. usualmente más susceptibles a precipitación que otros lugares del mundo debido a la humedad y la localización geográfica en donde la formación de nubes es mucho más probable. Ésta es la primera vez que un radar marino es modificado para aplicaciones meteorológicas y operado e instalado utilizando energía renovable. Los sistemas fotovoltaicos producen energía limpia y confiable sin emitir gases de invernadero como los combustibles fósiles. Los radares OTG son sistemas de baja potencia en banda X, lo que los hace una solución versátil para las necesidades energéticas de muchas aplicaciones. El diseño de un sistema fotovoltaico incluye la estimación de la carga eléctrica, especificación del banco de baterías, módulos solares, controlador de carga, inversor y el tamaño de los cables para el alambrado. Cabe señalar que, al determinar las baterías, es ne...
WSEAS Transactions on …, 2009
A rain gauge network (28 rain gauges) was installed in western Puerto Rico (PR) within a 4km x 4k... more A rain gauge network (28 rain gauges) was installed in western Puerto Rico (PR) within a 4km x 4km GOES satellite pixel. Located within the pixel is a well monitored sub-watershed of 3.55 km 2 , referred to here as the "testbed subwatershed" (TBSW). The rain gauge network was established to evaluate rainfall estimates from the GOES-based Hydro-Estimator (HE), NEXRAD radar and the Center for Collaborative Adaptive Sensing of the Atmosphere (CASA) radar network, which has a high spatial resolution (≈ 200 m). Furthermore, the rain gauge network will provide a high temporal and spatial resolution rainfall dataset to be input into a distributed hydrologic model in the TBSW.
WSEAS International Conference. …, 2009
ABSTRACT: A rain gauge network (28 rain gauges) was installed in western Puerto Rico (PR) within ... more ABSTRACT: A rain gauge network (28 rain gauges) was installed in western Puerto Rico (PR) within a 4x4 km GOES satellite pixel. Located within the pixel is a well monitored sub-watershed of 3.55 km2, referred to here as the testbed subwatershed(TBSW). The rain ...
Remote sensing QPE uncertainties associated with sub-pixel rainfall variation
... SW Washington, DC 20591.]. 5. Young, CB, BR Nelson, AA Bradley, JA Smith, CD Peters-Lidard, A... more ... SW Washington, DC 20591.]. 5. Young, CB, BR Nelson, AA Bradley, JA Smith, CD Peters-Lidard, A. Kruger, and ML Baeck, 1999: An evaluation of NEXRAD precipitation estimates in complex terrain. J. Geophys. ... Robert J. Kuligowski: colleagues. Ramón Vasquez: colleagues. ...
In this study, a large number of storms (> 60) were evaluated between August 2006 and August 2008... more In this study, a large number of storms (> 60) were evaluated between August 2006 and August 2008. The area covered by the rain gauge network was limited to a single GOES-12 pixel (4 km x 4 km). Five-minute and total storm rainfall amounts were spatially variable at the sub-pixel scale. The average storm rainfall from 20% of the 120 possible rain gauge-pairs was found to be significantly different at the 5% of significance level, indicating significant rainfall variation at the sub-pixel scale. The average coefficient of determination (r 2 ), describing the goodness of fit of a linear model relating rain gauge pairs, was 0.365, further suggesting a significant degree of variability at the satellite sub-pixel scale. Although there were several different storm types identified (localized, upper westerly trough, tropical easterly wave, tropical westerly trough, cold front and localized with cold front), there did not appear to be any relationship between storm type and the correlation patterns among the gauges.
A rain gauge network (28 rain gauges) was installed in western Puerto Rico (PR) within a 4x4 km G... more A rain gauge network (28 rain gauges) was installed in western Puerto Rico (PR) within a 4x4 km GOES satellite pixel. Located within the pixel is a well monitored sub-watershed of 3.55 km 2 , referred to here as the "testbed subwatershed" (TBSW). The rain gauge network was established to evaluate the performance of the GOES-based Hydro-Estimator (HE) rain rate algorithm, and estimated rain rates from NEXRAD radar and the Center for Collaborative Adaptive Sensing of the Atmosphere (CASA) radar network, which has a high spatial resolution (≈ 200 m). Furthermore, the rain gauge network will provide a high temporal and spatial resolution rainfall dataset to be input into a distributed hydrologic model in the TBSW.
Performance and Evaluation of Multisensor Precipitation Estimation Algorithm Using a High Density Rain Gauge Network and Hydrologic Simulation
21st Century Watershed Technology: Improving Water Quality and Environment Conference Proceedings, 21-24 February 2010, Universidad EARTH, Costa Rica, 2010
Page 1. Performance and Evaluation of Multisensor Precipitation Estimation Algorithm Using a High... more Page 1. Performance and Evaluation of Multisensor Precipitation Estimation Algorithm Using a High Density Rain Gauge Network and Hydrologic Simulation ALEJANDRA M. ROJAS GONZÁLEZ1, ERIC W. HARMSEN2, SANDRA CRUZ POL3 ...
Validation of the Hydro-Estimator (HE) and the Next Generation Radar (NEXRAD) during heavy storms... more Validation of the Hydro-Estimator (HE) and the Next Generation Radar (NEXRAD) during heavy storms over Puerto Rico (PR) is reported. The HE is a high resolution rainfall retrieval algorithm based on satellite and numerical whether prediction model data. The accuracy of the HE and the NEXRAD rainfall estimates can be measured by decomposing the rainfall process in sequences of discrete (rain / no rain) and continuous (rainfall rate) random variables. Validation results are based on five heavy storms that seriously impacted human life and the economy of PR during the period 2003 to 2005. The average discrete validation results indicate acceptable hit rate values for both the HE and NEXRAD (0.76 vs. 0.87) and reasonable discrete bias ratios (1.04 vs. 0.73) but a very low of probability of detection of rain for both the HE and NEXRAD (0.36 vs. 0.52). The HE shows an average overestimation whereas the NEXRAD exhibits underestimation in the continuous validation results (continuous bias ratio of 1.14 vs 0.70 for NEXRAD), which contributes to moderate overall errors for the HE and NEXRAD in terms of root mean squared error (2.14 mm vs. 1.66 mm) and mean absolute error (0.96 mm vs. 0.77 mm).
Flood alert system using rainfall forecast data in Western Puerto Rico
2013 IEEE International Geoscience and Remote Sensing Symposium - IGARSS, 2013
ABSTRACT The Western Puerto Rico area is subject to flooding due to sudden, extreme rainfall even... more ABSTRACT The Western Puerto Rico area is subject to flooding due to sudden, extreme rainfall events, some of which fail to be detected by NOAA's NEXRAD radar. The use of new radars with higher spatial resolution and covering the low atmosphere are vital for flood forecasting efforts, and for studying and predicting atmospheric phenomena. Recently the University of Puerto Rico in Mayagüez initiated investigations using two (2) types of these radars, Off-the Grid (OTG) and TropiNet (RXM-25), respectively, in the Mayagüez Bay Drainage Basin area. This is the first time that such radar technology will be used for hydrologic analyses and specifically for rainfall forecasting in Puerto Rico. The forecast analysis will be made using time series with autoregressive methods and selecting the stochastic model parameters most appropriate for an optimal prediction; with the radar results, a distributed hydrologic model (Vflo™) is used to obtain the spatial distribution of flooding depth.
awra.org
A hydrologic model will be used to perform real-time flood forecasting within the Mayaguez Bay dr... more A hydrologic model will be used to perform real-time flood forecasting within the Mayaguez Bay drainage basin (847 km 2 ), located in western Puerto Rico. Minimizing run times, for this relatively large model, is important, therefore, the grid size should be optimized (minimizing runtime), while still producing accurate results. In this study we used a numerical distributed hydrologic model to simulate the hydrologic response in a small Test Bed Subwatershed (TBSW) over a three months period (October 17-December 31, 2007) using gridded rainfall derived from a dense rain gauge network (28 rain gauges within 16 km 2 ). The TBSW is located within the Mayaguez Bay drainage basin and is characterized by high rainfall variability over short distances (< 200 m), has an area of 3.55 square km, 29 percent average slope, and soils classified predominantly as Hydrologic Group B (60% of TBSW). Stream stage elevation was measured continuously at the TBSW outlet for use in the model calibration. An evaluation of the interrelation between different upscaling parameters is being conducted to quantify their influence on hydrologic predictability. In this paper we present the results for the baseline grid size (10 m) ensemble with 100 m rainfall resolution for an event that occurred on October 22, 2007. This study also evaluates potential evapotranspiration (PET) calculations using different methods with a daily time step for 2 years, at 2 weather stations and at the TBSW.
WSEAS Transactions …, 2008
Validation of the Hydro-Estimator (HE) and the Next Generation Radar (NEXRAD) during heavy storms... more Validation of the Hydro-Estimator (HE) and the Next Generation Radar (NEXRAD) during heavy storms over Puerto Rico (PR) is reported. The HE is a high resolution rainfall retrieval algorithm based on satellite and numerical weather prediction model data. The accuracy of the HE ...
asprs.org
Due to the complex terrain and the tropical influence, Puerto Rico is characterized by small wate... more Due to the complex terrain and the tropical influence, Puerto Rico is characterized by small watersheds, high rainfall intensity and spatial variability. The rainfall anomalies are produced by orographic-convective type storms, tropical storms and hurricanes producing flash flooding in susceptible areas. An important source of uncertainty in hydrologic modeling in Puerto Rico is associated with the rainfall. There is typically not enough rain gauge density to calculate the associated bias, and to obtain spatial variability of point rainfall at scales below level III radar-based (NEXRAD) products (2x2 kilometers). How the uncertainty in rainfall distribution propagates through the hydrologic modeling process is a critical question, and is addressed in this paper. Another challenge to hydrologic prediction occurs when high slopes exist, and soil and land use characteristics change over short distances. Hydrologic models average the hydrologic parameters and topography in lumped, semi-distributed and distributed models to simplify and/or reduce computational time. The lumping process (i.e., grid upscaling) may lead to a loss in flash flood prediction accuracy. However, it is unknown how much lumping can be tolerated before accuracy of flood prediction degrades beyond an acceptable level.
… on Signal Processing, 2008
Rain gauge networks are used to calibrate and validate quantitative precipitation estimation (QPE... more Rain gauge networks are used to calibrate and validate quantitative precipitation estimation (QPE) methods based on remote sensing, which may be used as data sources for hydrologic models. The typical approach is to adjust (calibrate) or compare (validate) the rainfall in ...
Gordon CenSSIS Educational Component at UPRM
K-12 …, 2007
... Sandra Cruz Pol University of Puerto Rico - Mayaguez ... Recommended Citation Esiely-Barrera,... more ... Sandra Cruz Pol University of Puerto Rico - Mayaguez ... Recommended Citation Esiely-Barrera, Hadi; Rodríguez-Solís, Rafael; Pol, Sandra Cruz; and Ustariz, Jose Colom, "Gordon CenSSIS Educational Component at UPRM" (2007). K-12 Presentations. ...
CenSSIS Educational Component at UPRM
The educational component of CenSSIS at UPRM is centered on the High-Tech Tools and Toys Laborato... more The educational component of CenSSIS at UPRM is centered on the High-Tech Tools and Toys Laboratory. Most of the educational activities are carried out through this laboratory. The laboratory serves as a host to the introduction to Electrical Engineering ...
Relevance Of The Modified Model For The Microwave Brightness Temperature To The TOPEX/Poseidon Satellite Altimetry Mission
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Papers by Sandra Cruz-pol