Can GPM IMERG Capture Extreme Precipitation in North China Plain?

Dasheng Zhang,Jin Wu,Meihong Ma,Guoqiang Tang,Suying Ma,Tsechun Wang,Wei Wang,Xun Zhao,Mingxiang Yang

doi:10.3390/rs14040928

Abstract

Extreme precipitation events (EPE) often cause catastrophic floods accompanied by serious economic losses and casualties. The latest version (V06) of the Integrated Multi-satellite Retrievals for Global Precipitation Measurement (GPM IMERG) provides global satellite precipitation data from 2000 at a higher spatiotemporal resolution with improved quality. It is scientifically and practically important to assess the accuracy of the IMERG V06 in capturing extreme precipitation. This study evaluates the two widely used products of IMERG during 2000–2018, i.e., IMERG late run (IMERG-L) and IMERG final run (IMERG-F), in the densely populated and flood-prone North China Plain. The accuracy of the IMERG V06 is evaluated with ground measurements from rain gauge stations at multiple scales (hourly, daily, and seasonally). A novel target tracking method is introduced to extract three-dimensional (3D) extreme precipitation events, and the near-real-time uncalibrated PERSIANN-CCS (Precipitation Estimation from Remotely Sensed Information using Artificial Neural Networks Cloud Classification System) and GSMAP (Global Satellite Mapping of Precipitation) satellite data are added to further evaluate IMERG’s performance during extreme precipitation. Finally, for flash flood events induced by extreme rainfall in the Hebei Province from 15 to 23 July 2016, the accuracy of capturing the event with IMERG-F and IMERG-L was verified. Results reveal that IMERG-F is better than IMERG-L at all investigated scales (hourly, daily, and seasonally), but the difference between the two products is less at higher time resolutions. Both products manifest decreased performance when capturing 3D extreme precipitation events, and comparatively, IMERG-F performs better than IMERG-L. IMERG-F exhibits a distinct discontinuity in extreme precipitation thresholds between land and ocean, which is a limitation of IMERG-F not documented in previous studies. Moreover, IMERG-L and IMERG-F are comparable at an hourly scale for some metrics, which is beyond the expectation that IMERG-F is notably better than IMERG-L. This study provides a scientific basis for the performance of satellite precipitation products and contributes to guiding users when applying global precipitation products.

Highlights

Precipitation is a key component of the global water cycle [1]
This study evaluated the accuracy of the latest version of Integrated Multi-Satellite Retrievals for GPM (IMERG) V06 satellite precipitation products (IMERG-L and IMERG final run (IMERG-F)) in capturing extreme precipitation at multiple scales and compared IMERG to several other datasets in the North China Plain
We selected a typical flood event in the North China Plain to explore whether IMERG can capture extreme precipitation-triggering floods

Summary

Introduction

Precipitation is a key component of the global water cycle [1]. High-quality precipitation data are of great significance to industrial and agricultural production, water conservancy development, drought, and flood prevention [5]. The traditional method for obtaining precipitation data is to install a network of rain gauge stations with a specific spatial density. Accurate precipitation can be obtained at each station, the uneven distribution of rain gauge stations and the spatial discontinuity of precipitation data have obvious limitations [6,7]. Remote-sensing-based methods using radars or satellites have been increasingly applied to estimate precipitation and spatial distribution. Accurately estimating extreme precipitation and understanding its spatiotemporal evolution is critical [9]

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