Comparison Study of Multiple Precipitation Forcing Data on Hydrological Modeling and Projection in the Qujiang River Basin

Xianyong Meng,Jing Zhang,Yang Cao,Yongyu Song,Yuequn Lai,Yuyan Zhou

doi:10.3390/w12092626

Abstract

As a key factor in the water cycle and climate change, the quality of precipitation data directly affects the hydrological processes of the river basin. Although many precipitation products with high spatial and temporal resolutions are now widely used, it is meaningful and necessary to investigate and evaluate their merits and demerits in hydrological applications. In this study, two satellite-based precipitation products (Tropical Rainfall Measurement Mission, TRMM; Integrated Multi-satellite Retrievals for GPM, IMERG) and one reanalysis precipitation product (China Meteorological Assimilation Driving Datasets for the Soil and Water Assessment Tool (SWAT) model, CMADS) are studied to compare their streamflow simulation performance in the Qujiang River Basin, China, using the SWAT model with gauged rainfall data as a reference. The main conclusions are as follows: (1) CMADS has stronger precipitation detection capabilities compared to gauged rainfall, while TRMM results in the most obvious overestimation in the four sub-basins. (2) In daily and monthly streamflow simulations, CMADS + SWAT mode offers the best performance. CMADS and IMERG can provide high quality precipitation data for data-scarce areas, and IMERG can effectively avoid the overestimation of streamflow caused by TRMM, especially on a daily scale. (3) The runoff projections of the three modes under RCP (Representative Concentration Pathway) 4.5 was higher than that of RCP 8.5 on the whole. IMERG + SWAT overestimates the surface water resources of the basin compared to CMADS + SWAT, while TRMM + SWAT provides the most stable uncertainty. These findings contribute to the comparison of the differences among the three precipitation products and provides a reference for the selection of precipitation data in similar regions.

Highlights

The hydrological processes of a river basin are complex and usually analyzed by the hydrological model [1]
The specific performance metrics of the three products relative to the Gauged products in the four sub-basins are shown in Table 3, which are the Root Mean Square Error (RMSE) and Percentage Bias (PBIAS) of the daily scale data between the three products and the Gauged data
The main purpose of this study was to compare the differences in precipitation and streamflow simulations between CMADS, TRMM, IMERG, and Gauged data at the sub-basin scale in the Qujiang river basin

Summary

Introduction

The hydrological processes of a river basin are complex and usually analyzed by the hydrological model [1]. Meteorological data are the most important input item in the hydrological model, especially precipitation, which plays a key role in the hydrological process. The accuracy and sufficiency of these data affect the accuracy of the hydrological model’s results. Current historical meteorological data sources include gauged stations, satellite data, and reanalysis products [2]. The accuracy of gauged station data is highest, but due to various constraints the distribution of. Satellite-based precipitation products are obtained through retrieval algorithms based on remote sensing images combined with infrared and microwave data [4,5], and reanalysis products are created by combining station data and the climate model through data assimilation techniques [6]

Objectives

Methods

Results

Discussion

Conclusion