Estimating groundwater recharge for Hanoi, Vietnam

V Hung Vu; Broder J Merkel

doi:10.1016/j.scitotenv.2018.09.225

Estimating groundwater recharge for Hanoi, Vietnam

Sci Total Environ. 2019 Feb 15;651(Pt 1):1047-1057. doi: 10.1016/j.scitotenv.2018.09.225. Epub 2018 Sep 22.

Authors

V Hung Vu¹, Broder J Merkel²

Affiliations

¹ Institute for Geology, Technische Universität Bergakademie Freiberg, 09596 Freiberg, Germany; Faculty of Geology, Hanoi University of Mining and Geology, Hanoi, Viet Nam. Electronic address: hungvu2003@gmail.com.
² Institute for Geology, Technische Universität Bergakademie Freiberg, 09596 Freiberg, Germany.

PMID: 30266050
DOI: 10.1016/j.scitotenv.2018.09.225

Abstract

Determining groundwater recharge is in particular in areas with Monsoon rainfall a challenge. Several methods were used to estimate groundwater recharge for the first time ever for the urban area of Hanoi city, Vietnam. Water table fluctuation method (WTF), hydrograph analyses including recession curve displacement, graphical separation, the Automated Web GIS-Base Hydrology Analysis Tool (WHAT), and empirical formulas were utilized. The mean recharge is approximately 340 mm/year accounting for 20% of precipitation in the period 1996 to 2009 with a certain decrease during this period. Baseflow separation methods show the highest values, whereas the displacement recession curve obtains the lowest recharge. The WTF methods approximate values are close to the mean value of all other proxies. The differences between all proxies are around 10%, and Spearman correlation is statistically significant. This indicates that these methods can be used to estimate recharge for this area. With long-term data, however, the results of WTF appear more consistent and more reasonable than the other approaches.

Keywords: Base-flow separation; Graphical separation method, empirical formulas; Hydrograph analysis; Recession curve displacement; Water table fluctuation.