Department Surface Waters - Research and Management

How are dams changing water quality in tropical African rivers?

Artificial river impoundments disrupt the seasonality and dynamics of thermal, chemical, morphological and ecological regimes in river systems. These alterations affect the aquatic ecosystems in space and time and specifically modify the seasonality and the longitudinal gradients of important biogeochemical processes.
In this study, the concept of a “resilience scale” will be explored for different water quality parameters downstream of Kariba dam, the largest artificial lake in the Zambezi basin (South-East Africa). In particular, we aim to assess the degree of reversibility of the main downstream alterations (temperature, oxygen, nutrients) and consequently the quantification of their longitudinal extent.

Coupling in-situ measurements with hydraulic and hydrological parameters such as travel times will allow us to define a physically-based parametrization of the different resilience scales for tropical rivers.

This study is part of the DAFNE project, an H2020 EU project. The main goal of the DAFNE project is to integrate multiple and international expertise in order to establish a decision-analytic framework for the exploration of the Water-Energy-Food Nexus in transboundary river basins in Africa. Two case studies are considered: the Zambezi and the Omo River Basin.

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