Analysis of Precipitation Totals Based on Radar and Rain Gauge Data

The relationship between radar reflectivity (Z) and rainfall intensity (R) plays a crucial role in estimating precipitation and serves as a foundation for flood risk assessment. However, empirical Z–R relationships often introduce considerable uncertainty, making the correction of rainfall estimatio...

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Main Authors: Karol Dzwonkowski, Ireneusz Winnicki, Sławomir Pietrek, Jolanta Siewert
Format: Article
Language:English
Published: MDPI AG 2025-06-01
Series:Remote Sensing
Subjects:
Online Access:https://www.mdpi.com/2072-4292/17/13/2157
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author Karol Dzwonkowski
Ireneusz Winnicki
Sławomir Pietrek
Jolanta Siewert
author_facet Karol Dzwonkowski
Ireneusz Winnicki
Sławomir Pietrek
Jolanta Siewert
author_sort Karol Dzwonkowski
collection DOAJ
description The relationship between radar reflectivity (Z) and rainfall intensity (R) plays a crucial role in estimating precipitation and serves as a foundation for flood risk assessment. However, empirical Z–R relationships often introduce considerable uncertainty, making the correction of rainfall estimation errors a key challenge in remote-sensing-based applications. Developing an effective approach to reduce these deviations is, therefore, essential to improve the accuracy of radar-based precipitation measurements. This study aims to develop a methodology for analyzing radar-derived precipitation using dual-polarization radar measurements, with validation based on rain gauge observations. Three well-established Z–R relationships—Marshall–Palmer, Muchnik, and Joss—were applied to radar reflectivity values measured at two heights, 1 km and 1.5 km above ground level. The Marshall–Palmer relationship applied at a height of 1.5 km yielded the smallest deviations from rain gauge measurements. Both the mean absolute error (MAE) and average precipitation difference at this height were consistent, amounting to 1.99 mm, compared to 2.32 mm at 1 km. The range of deviations in all cases was 0.54–7.64 mm at 1.5 km and 0.65–7.18 mm at 1 km. Furthermore, all tested Z–R relationships demonstrated a strong linear correlation with rain gauge data, as indicated by a Pearson correlation coefficient of 0.98. These findings enable the identification of the most accurate Z–R relationships and optimal measurement heights for radar-based precipitation estimation. These results may have important implications for operational applications and the calibration of radar precipitation products.
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spelling doaj-art-2b77214fa41d4d03bb7876f137036e3c2025-08-20T03:50:20ZengMDPI AGRemote Sensing2072-42922025-06-011713215710.3390/rs17132157Analysis of Precipitation Totals Based on Radar and Rain Gauge DataKarol Dzwonkowski0Ireneusz Winnicki1Sławomir Pietrek2Jolanta Siewert3Institute of Geospatial Engineering and Geodesy, Faculty of Civil Engineering and Geodesy, Military University of Technology, 2 Gen. S. Kaliskiego St., 00-908 Warsaw, PolandInstitute of Geospatial Engineering and Geodesy, Faculty of Civil Engineering and Geodesy, Military University of Technology, 2 Gen. S. Kaliskiego St., 00-908 Warsaw, PolandInstitute of Geospatial Engineering and Geodesy, Faculty of Civil Engineering and Geodesy, Military University of Technology, 2 Gen. S. Kaliskiego St., 00-908 Warsaw, PolandInstitute of Geospatial Engineering and Geodesy, Faculty of Civil Engineering and Geodesy, Military University of Technology, 2 Gen. S. Kaliskiego St., 00-908 Warsaw, PolandThe relationship between radar reflectivity (Z) and rainfall intensity (R) plays a crucial role in estimating precipitation and serves as a foundation for flood risk assessment. However, empirical Z–R relationships often introduce considerable uncertainty, making the correction of rainfall estimation errors a key challenge in remote-sensing-based applications. Developing an effective approach to reduce these deviations is, therefore, essential to improve the accuracy of radar-based precipitation measurements. This study aims to develop a methodology for analyzing radar-derived precipitation using dual-polarization radar measurements, with validation based on rain gauge observations. Three well-established Z–R relationships—Marshall–Palmer, Muchnik, and Joss—were applied to radar reflectivity values measured at two heights, 1 km and 1.5 km above ground level. The Marshall–Palmer relationship applied at a height of 1.5 km yielded the smallest deviations from rain gauge measurements. Both the mean absolute error (MAE) and average precipitation difference at this height were consistent, amounting to 1.99 mm, compared to 2.32 mm at 1 km. The range of deviations in all cases was 0.54–7.64 mm at 1.5 km and 0.65–7.18 mm at 1 km. Furthermore, all tested Z–R relationships demonstrated a strong linear correlation with rain gauge data, as indicated by a Pearson correlation coefficient of 0.98. These findings enable the identification of the most accurate Z–R relationships and optimal measurement heights for radar-based precipitation estimation. These results may have important implications for operational applications and the calibration of radar precipitation products.https://www.mdpi.com/2072-4292/17/13/2157dual-polarization radarquantitative precipitation estimationprecipitation measurementsempirical relationships
spellingShingle Karol Dzwonkowski
Ireneusz Winnicki
Sławomir Pietrek
Jolanta Siewert
Analysis of Precipitation Totals Based on Radar and Rain Gauge Data
Remote Sensing
dual-polarization radar
quantitative precipitation estimation
precipitation measurements
empirical relationships
title Analysis of Precipitation Totals Based on Radar and Rain Gauge Data
title_full Analysis of Precipitation Totals Based on Radar and Rain Gauge Data
title_fullStr Analysis of Precipitation Totals Based on Radar and Rain Gauge Data
title_full_unstemmed Analysis of Precipitation Totals Based on Radar and Rain Gauge Data
title_short Analysis of Precipitation Totals Based on Radar and Rain Gauge Data
title_sort analysis of precipitation totals based on radar and rain gauge data
topic dual-polarization radar
quantitative precipitation estimation
precipitation measurements
empirical relationships
url https://www.mdpi.com/2072-4292/17/13/2157
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AT ireneuszwinnicki analysisofprecipitationtotalsbasedonradarandraingaugedata
AT sławomirpietrek analysisofprecipitationtotalsbasedonradarandraingaugedata
AT jolantasiewert analysisofprecipitationtotalsbasedonradarandraingaugedata