CHARM addresses five of the major challenges associated with the operation and management reservoirs: the deposition of fine sediments, the binding by microbial biofilms, the cause and development of cyanobacterial blooms as well as greenhouse gas emissions and social interests.
Reservoir sedimentation represents a huge challenge in reservoir management. Deposited sediments significantly reduce storage capacity, and might block intakes and outlets of a reservoir. Within CHARM, fundamental research is performed concerning the sediment stability of fine sediments in the field and in the laboratory. In a second step, algorithms will be developed for the numerical modelling of erosional processes that serve as the basis for predicting sediment dynamics and a sustainable reservoir management.
Microbial organisms inhabiting fine sediments can influence the erosion stability of sediments (known as 'biostabilization') as well as the characteristics of eroded flocs and its further transport and deposition. The role of biostabilization on sediment behavior will be investigated within CHARM using both field observations and manipulative experiments to examine the influence of abiotic conditions such as temperature, light and hydrodynamics on biofilm growth, community composition and functionality.
Many reservoirs experience high nutrient input which can favour harmful cyanobacterial (blue-green algae) blooms leading ultimately to a decreased water quality. To develop countermeasures, physico-chemical and biological processes are explored that may be relevant in triggering bloom formation. The main focus is on the toxin production of these microorganisms as well as on the impact of water level fluctuations, seasonal changes and external water supply.
Green House Gases (GHGs)
If deposited sediments are remobilized, internally produced and climate-relevant gases such as methane are likely to be released. Spatially and temporally resolved measurements of these GHGs will help to quantify their emissions from reservoirs into the atmosphere. A specific focus is on the influence of reservoir management on the production, storage and emissions pathways of CO2 and CH4.
Reservoirs represent a major impact on landscape and the social surrounding. Moreover, the reservoir management might imply further conflicts of interests between operators and various stakeholders. These societal implications connected to reservoirs will be analyzed with the help of regional case studies to finally derive to integrated, cross-linked management concepts.