Delay in lake recovery caused by internal loading
A simplified model of a lake-sediment system is proposed, which aims to predict the long-term evolution and the recovery time of eutrophied lakes. The model represents the state of lake and sediment each by means of a single variable. Particular attention is devoted to the consequences of P saturation of the solid phase in surface sediment layers, i.e. to a situation which is frequently present in eutrophied lakes. The model is applied to the case of the highly eutrophied Lake Varese (Northern Italy), in which internal P loadings from sediments appear to be substantial. Taking into account the coupling between lake and sediments, the time needed to attain the steady state P concentration compatible with the present P loadings is evaluated as approximately 5 times the water renewal time of the lake. It is also shown to what extent the assumptions on sediment dynamics affect the model predictions.
Bibliographic Reference: Article: Water Research, Vol. 25 (1991) No. 5, pp. 567-575
Record Number: 199111165 / Last updated on: 1994-12-02
Original language: en
Available languages: en