Inland waters are an important part of the water-carbon cycle. Oxygen-poor zones, high nutrient loads and the decomposition of organic matter can promote the formation and release of methane.
The climate effect cannot, however, be derived reliably from individual water-quality readings. This requires a robust baseline, suitable process data and scientifically traceable models.
The Advanced Lake Biochemistry Model (ALBM) brings together relevant biogeochemical processes and leading indicator parameters. Methane emissions are not presented as a directly measured quantity unless direct gas measurement is carried out. Instead, they are determined using a model-based approach, including the assumptions and uncertainties this entails.
Step by step, the climate effect of measures such as de-sludging, restoration, altered through-flow or optimised turbine flows can thus be assessed against the baseline. In the longer term, such evidence can also become relevant for climate-finance and certification models.