A high-resolution global runoff estimate based on GIS and an empirical runoff coefficient

• Published in: Hydrology Research Vol. 51; no. 6; pp. 1238 - 1260
• Main Authors: Liang, Shumin, Greene, Richard
• Format: Journal Article
• Language: English
• Published: London IWA Publishing 01-12-2020
• Subjects: Arid regions; Arid zones; Basins; Climate; Coefficients; Depth; Deserts; geographic information system; Geographic information systems; Geographical information systems; global runoff; Groundwater; Groundwater recharge; Groundwater runoff; High resolution; Hydrology; Information systems; interior drainage; Mathematical analysis; Precipitation; Productivity; Remote sensing; Resolution; Rivers; Runoff; Runoff coefficient; Runoff estimation; Runoff volume; Seasons; Semi arid areas; Semiarid lands; Semiarid zones; Variables; Watersheds; China; Antarctica; Africa
• ISSN: 0029-1277; 1998-9563; 2224-7955
• DOI: 10.2166/nh.2020.132

Abstract
This paper reviews 110 years of global runoff estimation. By employing the method of ordinary least square regression on a sample region's runoff coefficient, an empirical formula of a runoff coefficient is calculated for China. Based on this empirical formula applied with a high-resolution grid of precipitation, runoff is calculated resulting in an equally high-resolution map of global runoff using a geographic information system (GIS). The main results are (1) the global total runoff volume is 47,884 km3, (2) the average runoff depth is 359 mm, (3) the interior drainage region's runoff volume is 1,663 km3, and (4) the average runoff depth is 58.4 mm. The results are compared with the results of the existing literature on global runoff. This study emphasizes the importance of runoff and groundwater recharge in arid and semi-arid regions where the estimation value of runoff depth is significantly increased.