Global River in Perspective - Mekong

Columbia University, GSAPP, Urban Design Studio III, Summer 2021
Collaborators: Zuzanna Jarzynska, Aruna Ananta Das, Cheng Ju Lee
Advisors: Kate Orff, Geeta Mehta, Dilip Da Cunha, Adriana Chavez, Justine Holzman, Tori Vuono

As part of the Water Urbanism studio situated in the Mississippi river basin, the Mekong or the Lancang River, flowing across 5 South East Asian countries and China, has been chosen as a case study to compare with. The river is a vital economic resource as well as a heated contested site between upper and lower stream countries.

Physicality and Settlements

Although similar to Mississippi in terms of the volume of discharge, the Mekong is 4 times smaller in terms of drainage area while the size of delta and amount sediment discharge are similar. In comparison to Mississippi, it is less regulated, less leveed. For example, in the town of Luang Prabang, dikes were only started to get built in 2008. It is distant from the river separated by a floodplain left for the water level to increase. At the outlet, a water city like CanTho in Vietnam has been embracing the wetness through its planning, lifestyle and architecture for centuries. These are things that cities in the Mississippi could learn from.

The Pulse of Mekong

The hydrological cycle of the Mekong River is considered to be a natural wonder of the world. During wet season, the river flows backward and expand the Tonle Sap more than 5 times its original size with depth increased from 1-2 meters to around 8 meters. Flooding of the adjacent forests makes a perfect Nursery for small fishes with nutrients and hiding place from predators while the soil is nourished by the flood. When water recedes, grown fishes migrate throught the river and fertile soil is available for farming.  Therefore, People have adapted their housing/ farming cycle and methods to this massive fluctuations and 80% of Cambodians are dependent on this change in water level.

Dams, Politics and the Environment

Since the river is shared between 6 countries with China holding its upstream, there have been problems with coordination in the operation. With steeper topography, China has constructed cascading dams for hydroelectric power production since the 1990s. Water cycle has been altered based on needs like power grid maintenance instead of following the agricultural cycle downstream. Countries like Laos also invested heavily in hydroelectric dams to become batteries of Asia and export their energy. To mitigate coordination issues, 5 countries formed the Lower Mekong Commission sponsored by the US, Japan and Korea while China refused to join. In 2019, China started holding water without informing lower countries which caused one of the worst draughts on a river that 60 million people rely on.

The environmental effects of the dams cause a lot of chain effects that are beyond political boundaries. The dams in the upstream will block the sediment flow and at the same time hinder fish migration. This ends up coastline erosion and the loss of mangroves. Moreover, because the dams are holding water upstream, it results in a lot of issues related to the rice field in the Mekong delta. The irregular drought, crop failure, groundwater abstraction, land subsidence and saltwater intrusion are forcing an economic transition in the Mekong delta.

Threats to the River

Like what happened to the Mississippi in the last century, rapid industrialization and construction of infrasturctures have afffected the traditional way of life  around the river and changed the human-nature relationship. This resulted in soil degradation and land subsidence.