Stable isotope signatures of meteoric water in the Cuvelai-Etosha Basin, Namibia: Seasonal characteristics, trends and relations to southern African patterns

Wanke, Heike; Gaj, Marcel; Beyer, Matthias; Koeniger, Paul; Hamutoko, Josefina T.

Abstract

© 2018, © 2018 Informa UK Limited, trading as Taylor & Francis Group. The study area is the Namibian part of the Cuvelai-Etosha Basin (CEB), located in central northern Namibia. The CEB is home to 40% of Namibia’s population, and most of the people live in rural areas. These people depend on both surface and groundwater resources which are limited in this dryland (mean annual rainfall ranging from 250 to 550 mm/a). The isotopic signatures of δ 18 O and δ 2 H from water samples (n = 61) collected over a course of 9 years from various research projects and existing (but mainly unpublished) data of meteoric water of the CEB (10 sites) were evaluated and local meteoric water lines (LMWLs) developed. Further, the data is discussed in the context of seasonal characteristics and trends and compared to available data from the Global Network of Isotopes in Precipitation (GNIP) for the southern African region. Our results extend the portfolio of previously published LMWLs for southern Africa and provide a more precise baseline for any isotope-based study in that region. The slope of the LMWL from the GNIP stations correlates with latitude. This correlation cannot be found within the CEB. The dominant control on the isotopic signature of the CEB of precipitation is seasonal.

• Journal Article Type: Article
• Acceptance Date: Jun 18, 2018
• Online Publication Date: Aug 6, 2018
• Publication Date: Nov 2, 2018
• Deposit Date: Feb 19, 2019
• Journal: Isotopes in Environmental and Health Studies
• Print ISSN: 1025-6016
• Electronic ISSN: 1477-2639
• Publisher: Taylor & Francis
• Peer Reviewed: Peer Reviewed
• Volume: 54
• Issue: 6
• Pages: 588-607
• DOI: https://doi.org/10.1080/10256016.2018.1505724
• Keywords: Hydrogen-2, isotope, hydrology, local meteoric, water line, Namibia, oxygen-18, precipitation
• Public URL: https://uwe-repository.worktribe.com/output/863167
• Publisher URL: https://doi.org/10.1080/10256016.2018.1505724
• Contract Date: Feb 19, 2019