Partitioning groundwater recharge sources in multiple aquifers system within a desert oasis environment: implications for water resources management in endorheic basins

Guo, Xiaoyan and Feng, Qi and Si, Jianhua and Xi, Haiyang and Zhao, Yan and Deo, Ravinesh C. ORCID: https://orcid.org/0000-0002-2290-6749 (2019) Partitioning groundwater recharge sources in multiple aquifers system within a desert oasis environment: implications for water resources management in endorheic basins. Journal of Hydrology, 579 (Article 124212). ISSN 0022-1694


Abstract

The global expansion of irrigation-based agricultural practices is causing an overexploitation of groundwater resources. A thorough understanding of groundwater recharge processes is necessary for restoring groundwater and improving water resources management, especially in desert oasis aquifers in endorheic basins. In this paper, the Ejina Oasis in the downstream of Heihe River Basin was selected as the representative case for such an endeavor. Based on stable isotopes and end member mixing analysis, we found that the shallow groundwater was modern water, with 13% originating from local precipitation and 87% from river water infiltration. The semi-confined groundwater is a mixture of shallow groundwater (30%), lateral groundwater flowing from the middle Heihe River Basin (MHR; 52%), and confined groundwater (18%). Confined groundwater was old water formed in paleo-climatic humid and cold conditions. Shallow groundwater levels were restored substantially after implementation of the Ecological Water Diversion Project (EWDP) began in 2000 in the Heihe River Basin, but the semi-confined groundwater levels still declined slowly. These different responses to EWDP are attributed to the differences in primary recharge sources of the two aquifers. Because river water infiltration was the main sources of shallow groundwater, increases in river discharge into the Ejina Oasis resulted in increased shallow groundwater levels over a short time scale. Continued over-pumping of groundwater for irrigation in the MHR
reduced lateral groundwater flow into the lower Heihe River Basin, which was the primary source of semiconfined groundwater. For successful groundwater restoration and maintenance of groundwater for the future, EWDP implementation must integrate water management of river water and groundwater diversion across the whole basin. Our results can provide useful information on policy decision makers for sustainable use of water resources in the oases of other similar watersheds around the world.


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Item Type: Article (Commonwealth Reporting Category C)
Refereed: Yes
Item Status: Live Archive
Additional Information: Permanent restricted access to Published version, in accordance with the copyright policy of the publisher.
Faculty/School / Institute/Centre: Current - Faculty of Health, Engineering and Sciences - School of Sciences (6 Sept 2019 -)
Faculty/School / Institute/Centre: Current - Institute for Life Sciences and the Environment - Centre for Sustainable Agricultural Systems (1 Aug 2018 -)
Date Deposited: 09 Oct 2019 23:46
Last Modified: 21 Nov 2019 05:25
Uncontrolled Keywords: oasis; aquifer; stable isotope; groundwater recharge; water resources management
Fields of Research (2008): 05 Environmental Sciences > 0502 Environmental Science and Management > 050204 Environmental Impact Assessment
Socio-Economic Objectives (2008): E Expanding Knowledge > 97 Expanding Knowledge > 970105 Expanding Knowledge in the Environmental Sciences
Identification Number or DOI: 10.1016/j.jhydrol.2019.124212
URI: http://eprints.usq.edu.au/id/eprint/37171

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