water Article Water and Suspended Sediment Budgets in the Lower Mekong from High-Frequency Measurements (2009–2016) Dang Thi Ha 1, Sylvain Ouillon 2,3,* ID and Giap Van Vinh 4 1 School of Maritime Economics and Technology, Ba Ria-Vung Tau University, 84254 Ba Ria-Vung Tau, Vietnam;
[email protected] 2 LEGOS, Univ. Toulouse, IRD, CNRS, CNES, 14 av. E.-Belin, 31400 Toulouse, France 3 Department of Water Environment Oceanography, University of Science and Technology of Hanoi (USTH), 18 Hoang Quoc Viet, 100000 Hanoi, Vietnam 4 Cuu Long River Hydrological Center, Southern Regional Hydro-Meteorological Center (SRHMC), 84282 Can Tho, Vietnam;
[email protected] * Correspondence:
[email protected]; Tel.: +33-561332935 Received: 19 April 2018; Accepted: 20 June 2018; Published: 26 June 2018 Abstract: Based on a new dataset of high temporal resolution of water discharge (hourly frequency) and suspended sediment concentration (twice daily frequency at ebb and flood tides) at Can Tho and My Thuan stations during the 2009–2016 period, monthly and annual flow and suspended sediment flux of the lower Mekong River were calculated. The present water discharge of the Mekong River to the sea can be estimated to be 400 km3 yr−1, +/− 100 km3 yr−1 depending on El Niño Southern Oscillation (ENSO), and the present sediment supply to the sea can be estimated to be 40 Mt yr−1, +/− 20 Mt yr−1 depending on ENSO. The ENSO influence (proxied by the Southern Oscillation Index—SOI) on Q (water discharge) and Qs (sediment flux) is at maximum at a time lag of 8–9 months.