Show simple item record

dc.contributor.authorTang, Guoqiang
dc.contributor.authorBehrangi, Ali
dc.contributor.authorLong, Di
dc.contributor.authorLi, Changming
dc.contributor.authorHong, Yang
dc.date.accessioned2018-07-24T19:03:00Z
dc.date.available2018-07-24T19:03:00Z
dc.date.issued2018-04
dc.identifier.citationTang, G., Behrangi, A., Long, D., Li, C., & Hong, Y. (2018). Accounting for spatiotemporal errors of gauges: A critical step to evaluate gridded precipitation products. Journal of Hydrology, 559, 294-306. https://doi.org/10.1016/j.jhydrol.2018.02.057en_US
dc.identifier.issn00221694
dc.identifier.doi10.1016/j.jhydrol.2018.02.057
dc.identifier.urihttp://hdl.handle.net/10150/628288
dc.description.abstractRain gauge observations are commonly used to evaluate the quality of satellite precipitation products. However, the inherent difference between point-scale gauge measurements and areal satellite precipitation, i.e. a point of space in time accumulation v.s. a snapshot of time in space aggregation, has an important effect on the accuracy and precision of qualitative and quantitative evaluation results. This study aims to quantify the uncertainty caused by various combinations of spatiotemporal scales (0.1 degrees-0.8 degrees and 1-24 h) of gauge network designs in the densely gauged and relatively flat Ganjiang River basin, South China, in order to evaluate the state-of-the-art satellite precipitation, the Integrated Multi satellite Retrievals for Global Precipitation Measurement (IMERG). For comparison with the dense gauge network serving as "ground truth", 500 sparse gauge networks are generated through random combinations of gauge numbers at each set of spatiotemporal scales. Results show that all sparse gauge networks persistently underestimate the performance of IMERG according to most metrics. However, the probability of detection is overestimated because hit and miss events are more likely fewer than the reference numbers derived from dense gauge networks. A nonlinear error function of spatiotemporal scales and the number of gauges in each grid pixel is developed to estimate the errors of using gauges to evaluate satellite precipitation. Coefficients of determination of the fitting are above 0.9 for most metrics. The error function can also be used to estimate the required minimum number of gauges in each grid pixel to meet a predefined error level. This study suggests that the actual quality of satellite precipitation products could be better than conventionally evaluated or expected, and hopefully enables non-subject-matter expert researchers to have better understanding of the explicit uncertainties when using point-scale gauge observations to evaluate areal products. (C) 2018 Elsevier B.V. All rights reserved.en_US
dc.description.sponsorshipNational Key Research and Development Program of China [2016YFE0102400]; National Natural Science Foundation of China [71461010701, 91437214, 91547210]; NASA [NNH13ZDA001N-NEWS, NNH13ZDA001N-Weather]; National Aeronautics and Space Administration; China Scholarship Council (CSC)en_US
dc.language.isoenen_US
dc.publisherELSEVIER SCIENCE BVen_US
dc.relation.urlhttp://linkinghub.elsevier.com/retrieve/pii/S0022169418301392en_US
dc.rights© 2018 Elsevier B.V. All rights reserved.en_US
dc.subjectPrecipitationen_US
dc.subjectIMERGen_US
dc.subjectRain gaugeen_US
dc.subjectGauge densityen_US
dc.subjectEvaluationen_US
dc.subjectError functionen_US
dc.titleAccounting for spatiotemporal errors of gauges: A critical step to evaluate gridded precipitation productsen_US
dc.typeArticleen_US
dc.contributor.departmentUniv Arizona, Dept Hydrol & Atmospher Scien_US
dc.identifier.journalJOURNAL OF HYDROLOGYen_US
dc.description.note24 month embargo; published online: 21 February 2018en_US
dc.description.collectioninformationThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at repository@u.library.arizona.edu.en_US
dc.eprint.versionFinal accepted manuscripten_US
dc.source.journaltitleJournal of Hydrology
dc.source.volume559
dc.source.beginpage294
dc.source.endpage306


Files in this item

Thumbnail
Name:
manuscript_R2_clean.pdf
Size:
2.043Mb
Format:
PDF
Description:
Final Accepted Manuscript

This item appears in the following Collection(s)

Show simple item record