Assessment of Four Satellite-Based Precipitation Products Over the Pearl River Basin, China

Xiaolin Xia,Yangxiaoyue Liu,Ling Yao,Wenlong Jing

doi:10.1109/access.2021.3095239

Abstract

Precipitation is a major driven factor in water cycle and hydrological process. Since satellite sensors have been the main sources for acquiring globally continuous precipitation data, inter-comparison between satellite precipitation products (SPPs) from different sensors becomes increasingly significant, especially at daily or sub-daily scale and in regions suffering from frequent heavy rainfall and floods. This paper assessed the performance of four daily SPPs, including data from the Tropical Rainfall Measuring Mission (TRMM), Climate Hazards group Infrared Precipitation with Stations (CHIRPS), Climate prediction center MORPHmorphing technique (CMORPH) and Advanced SCATterometer (ASCAT) based Soil Moisture to RAINfall algorithm (SM2RAIN-ASCAT), using the ground gauge measurements from 2010 to 2014 over the Pearl River Basin (PRB), China. Accuracy of precipitation estimates and the capability in detecting rainy/non-rainy days and different precipitation categories were evaluated at both basin and station scale. The findings show that: 1) Performance of the SPPs varies temporally and spatially, and better performance can be observed in wet season and south-eastern part of the PRB, when or where precipitation is abundant. 2) All SPPs have poor performance in estimating extreme precipitation in the PRB; 3) Among the four SPPs, TRMM 3B42 exhibits the best performance in the PRB, followed by CMORPH, while CHIRPS performs the worst and is inapt for precipitation estimates in the PRB; SM2RAIN-ASCAT has quite high estimate errors, but it shows advantages against other products in detecting heavy precipitation events. Findings in this study are compared with recent studies conducted in other regions, and some limitations are discussed. This study provides significant reference for understanding the performance of daily SPPs in the PRB as well as areas with similar climate and surface condition.

Highlights

Serving as a significant medium for energy exchange between the land surface and the atmosphere, precipitation is essential for modelling water cycle and has important impact on human living environments [1,2,3,4]
ASSESSMENT ON BASIN SCALE the whole Pearl River Basin (PRB) is treated as one unit to calculate daily precipitation of gauge measurements and four satellite-based precipitation product (SPP)
Among the four SPPs, values derived from Tropical Rainfall Measuring Mission (TRMM) 3B42 and Center MORPHing technique (CMORPH) show more consistent patterns with the gauge measurements, while values from Climate Hazards group Infrared Precipitation with Stations (CHIRPS) have larger errors on days with intense rainfalls and values from SM2RAIN-Advanced SCATterometer (ASCAT) exhibit significant errors on most of the days during the study period

Summary

Introduction

Serving as a significant medium for energy exchange between the land surface and the atmosphere, precipitation is essential for modelling water cycle and has important impact on human living environments [1,2,3,4]. In the last few decades, precipitation in the basin has experienced decreasing trends in the upstream area and increasing intensity in the downstream area, and the number of raining days in the whole basin has been much less than before [8,9]. The shortage of water supply caused by the decreased precipitation in the upstream and the excessive rainwater caused by the intense precipitation in the downstream have aggravated the imbalance of water resources and the uncertainty of water supply in this area [12]. Coupled with rapid population growth and socialeconomic development, water use policy and management issues are facing great challenges in the PRB [13]

Methods

Results

Conclusion