Spatio-temporal variations of sea level around the Mekong Delta: their causes and consequences on the coastal environment |

Spatio-temporal variations of sea level around the Mekong Delta: their causes and consequences on the coastal environment

May 25th, 2016

Danet Hak, Kazuo Nadaoka, Lawrence Patrick Bernado, Vo Le Phu, Nguyen Hong Quan, To Quang Toan, Nguyen Hieu Trung, Duong Van Ni, Van Pham Dang Tri
Received 2016/01/13, Accepted 2016/03/28, Published 2016/05/25

Danet Hak1), Kazuo Nadaoka1), Lawrence Patrick Bernado2), Vo Le Phu3), Nguyen Hong Quan4), To Quang Toan5), Nguyen Hieu Trung6), Duong Van Ni6), Van Pham Dang Tri6)

1) School of Environment and Society, Tokyo Institute of Technology
2) Graduate School of Science and Engineering, Tokyo Institute of Technology
3) Faculty of Environment & Natural Resources, Ho Chi Minh City University of Technology – Vietnam National University, Vietnam
4) Institute for Environment and Resources (IER) – Vietnam National University of Ho Chi Minh City, Vietnam
5) Training & International Coordination Department, Southern Institute of Water Resources Research, Vietnam
6) College of Environment and Natural Resources, Can Tho University, Vietnam

This paper presents a comprehensive analysis of sea level variations around the Mekong Delta, and their causes and consequences on the environment, based on the tidal records from several stations. The results of the analysis revealed significant spatio-temporal sea level variations along the delta coast. Tidal fluctuations showed their local peaks around the river mouth with shallow bottom areas. The prevailing winds were identified as the factor governing the remarkable seasonal variability of the mean sea levels along the southern coast of the delta. From 1985 to 2010, the relative sea level along the southern coast of the delta rose by about 3.3 mm y–1. This rate of rise combined with the effect of land subsidence renders the Mekong Delta alarmingly susceptible to frequent inundation. Moreover, the immediate impacts, including saline intrusion and occasional inundation due to seasonal sea level fluctuation, are also found to be critical and require urgent attention. These findings suggest the need to revise coastal management strategies to prioritize the immediate effects of short-term sea level fluctuations and to increase the focus on local management issues such as groundwater pumping causing land subsidence and local sea level trends in addition to the global threats.

[Full Text]