Water Level Variation at the Upstream of Mekong Delta Area under the Impacts of Climate Variability and Hydropower Dam

Abstract

In the past two decades, the construction of hydropower dams in the upstream Mekong River is receiving public concerns due to potential impacts on the downstream ecosystems. As a result of water demand for hydropower dams and irrigation activities, many hydropower dams have operating along the mainstream, leading to a significant change in the downstream flow regime. In addition, the impacts of climate change in the recent decades also contribute to the variation of water level in the Mekong Delta Area (MDA). By 2016, fifty-six dams have been constructed, going into operation and have raising great public concern because they alter the hydrologic regime of the MDA. The aim of this study, therefore, is to evaluate the impact of existing dams and local rainfall on the flow regime in the MDA. Results carried out that alterations in water levels at two Tan Chau and Chau Doc stations in the upstream of MDA has already occurred since 2010 because of the operation of upstream hydropower dams. Results also showed that the change in local rainfall under the impact of climate variability contributed insignificantly to the change in water level at both Tan Chau and Chau Doc stations.