water Article Seasonally Variant Stable Isotope Baseline Characterisation of Malawi’s Shire River Basin to Support Integrated Water Resources Management Limbikani C. Banda 1,*, Michael O. Rivett 2, Robert M. Kalin 2 , Anold S. K. Zavison 1, Peaches Phiri 1, Geoffrey Chavula 3, Charles Kapachika 3, Sydney Kamtukule 1, Christina Fraser 2 and Muthi Nhlema 4 1 Ministry of Irrigation and Water Development, Tikwere House, Private Bag 390, Lilongwe 3, Malawi;
[email protected] (A.S.K.Z.);
[email protected] (P.P.);
[email protected] (S.K.) 2 Department of Civil & Environmental Engineering, University of Strathclyde, Glasgow G1 1XJ, UK;
[email protected] (M.O.R.);
[email protected] (R.M.K.);
[email protected] (C.F.) 3 Departments of Civil Engineering and Land Surveying, University of Malawi—The Polytechnic, Private Bag 303, Blantyre 3, Malawi;
[email protected] (G.C.);
[email protected] (C.K.) 4 BASEflow, P.O. Box 30467, Blantyre, Malawi; muthi@baseflowmw.com * Correspondence:
[email protected] Received: 28 February 2020; Accepted: 8 May 2020; Published: 15 May 2020 Abstract: Integrated Water Resources Management (IWRM) is vital to the future of Malawi and motivates this study’s provision of the first stable isotope baseline characterization of the Shire River Basin (SRB). The SRB drains much of Southern Malawi and receives the sole outflow of Lake Malawi whose catchment extends over much of Central and Northern Malawi (and Tanzania and Mozambique). Stable isotope (283) and hydrochemical (150) samples were collected in 2017–2018 and analysed at Malawi’s recently commissioned National Isotopes Laboratory.