Eutrophication Models for Lakes

Abstract

In the years 1970-1977 eutrophication models have been developed and applied for about 15 shallow Danish lakes. The structure of these models are discussed. An example of the calibration of the model on data from Lake Gyrstinge in the Suså catchment area is shown, and the use of the model for calculating ecological consequences of changed hydraulic retention times is demonstrated. The dynamic eutrophication model is compared to the Dillon-Rigler version of the input-output model. Limitations of both types of models are discussed.

Modelling eutrophication in lake ecosystems: A review

“…Several purposes have led to the development of lake eutrophication models. Although eutrophication models are not only used for management purposes but also for research (Simonsen and Dahl-Madsen, 1978;Vanhuet, 1992), we will focus in this paper mainly on the management objectives. In the keyword analysis, the words "management", "simulation", "prediction" and "restoration" appear respectively, in 54, 49, 31 and 6 22 references of the bibliographic corpus, which represents 12%, 11%, 7% and 5% of the references.…”

“…As they are based on a steady-state assumption, input-output models fail to "predict the dynamic trend of eutrophication in a large reservoir with temporal variation in inflow and storage" (Afshar et al, 2012). Moreover, these models "do not describe the biological variables which are of main interest" and "do not take into account the influence of biological processes on the model parameters" and some "important interactions between several phytoplankton limiting factors, light, phosphorus, nitrogen" (Simonsen and Dahl-Madsen, 1978).…”

Maritime-archaeological investigations of the Hanseatic harbour at Avaldsnes

“…Asbjørn Simonsen from the Museum of Archaeology in Stavanger, took a core sample in the inner bay for a sediment and botanical analysis together with material for C14 dates in 1978. 13 The layer of mud here was 1 m thick covering a former seabed consisting of sand, gravel and shells. The upper 50 cm of the organic layer contained fragments of charcoal which, according to Simonsen, was probably caused by an increased activity in the harbour.…”