Study shows Chinese hydropower operations considerably increased dry season flows and decreased wet season flows

January 6, 2017, Aalto University
Study shows Chinese hydropower operations considerably increased dry season flows and decreased wet season flows
Mekon River livelihoods and food security are closely linked to water. Credit: Aalto University

A study led by researchers from Aalto University in Finland reveals that the hydropower projects in China have caused major river flow changes to the Mekong River since the year 2011. An analysis of river flows in Northern Thailand indicates that the hydropower operations considerably increased dry season flows and decreased wet season flows. Furthermore, the study shows that the dry season flows have also become increasingly variable.

The river flow impacts were largest in 2014 after completion of the Nuozhadu dam, the largest hydropower project in the Mekong Basin, and the impacts were observable over 2000 km downstream in Cambodia. The hydropower operations dampened the Mekong River's annual flood, which is a key driver of the ecological productivity of the river.

"The changes are feared to affect the ecological productivity of the river and thus the livelihoods, economy and food security of the downstream people. In particular the impacts on fishing are a major concern because fish and other aquatic animals play a major role in the local and regional economy and food supply," says researcher Timo Räsänen.

He continues: "However, the ecological and social consequences of the hydropower operations are not yet well understood and more research is needed. The downstream countries are also building hydropower stations and the cumulative impacts need further attention. Therefore the research highlights the importance of strong transboundary cooperation between upstream and downstream countries for understanding and mitigating the negative consequences."

Credit: Aalto University

The Mekong River is one of the world's largest rivers and it provides livelihoods and food security for millions of people. The energy demand is growing rapidly in the region, and in recent years China has built large in the upper reaches of the Mekong River. This has raised concerns about the potentially harmful impacts on the river and downstream countries.

Despite these concerns the upstream hydropower companies have not shared publicly information about the expected or observed downstream impacts of the hydropower development.

Explore further: Vietnam warns of dire impact from planned Mekong dams

More information: Timo A. Räsänen et al. Observed river discharge changes due to hydropower operations in the Upper Mekong Basin, Journal of Hydrology (2017). DOI: 10.1016/j.jhydrol.2016.12.023

Related Stories

Vietnam warns of dire impact from planned Mekong dams

April 5, 2016

Research commissioned by Vietnam has warned of devastating environmental and economic effects for millions of people living along the Mekong River if 11 proposed dams are built on its mainstream.

Recommended for you

Paris climate targets could be exceeded sooner than expected

September 17, 2018

A new study has for the first time comprehensively accounted for permafrost carbon release when estimating emission budgets for climate targets. The results show that the world might be closer to exceeding the budget for ...

More ships and more clouds mean cooling in the Arctic

September 17, 2018

With sea ice in the Arctic melting at an alarming rate, opportunities for trans-Arctic shipping are opening up, and by mid-century ships will be able to sail right over the North Pole—something not previously possible for ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.