Environmental Engineering Reference
In-Depth Information
Chapter 19
Lake Glumsø: Case Study on Modelling a Small
Danish Lake
Søren Nors Nielsen and Sven Erik Jørgensen
Abstract The case study on the small Danish post-glacial Lake Glumsø shows
some of the highlights of aquatic ecosystem research over the time span of more
than 30 years. The research at Lake Glumsø is closely linked to the development of
ecological modelling as a discipline, inspired a wide range of related working
approaches as well as advancements in ecological modelling and the development
in ecological theory.
In the early working phase, models based on differential equations were used
not only to describe the lake processes but also to methodologically identify the
optimal formalisation of the described processes. First, modelling applications were
continuously improved, thus providing a large body of functional representations
for the different compartments. A result of the intense discussions of the early
model structures was a new approach called structural dynamic modeling which
allowed for varying numbers of variables and a model structure that could change
during simulation time. Continuing the search for optimal trade-off between model
complexity on one side and efficiency and precision on the other side, machine
learning techniques were applied to find out, whether this could help to identify the
most reasonable model structures which were tested with Lake Glumsø data and
many other lakes world wide. In further contributions to ecological theory, the
question was tackled whether overall ecosystem characteristics, like exergy, bio-
mass production or species composition, do converge in a successional process
towards optimal values. This led to the development of ecosystem goal functions,
which was part of an international ecosystem research debate on the theoretical
patterning and the dynamics of ecosystems.
Collaborating research groups on ecosystem research benefited very much
fromtheexperiencesmadeandtheknowledgegainedfromtheLakeGlumsø
studies.
