Evaluating the Hypotheses of the Steady-state Phosphorus Models for Lakes
Abstract
Lake eutrophication is one of the most pressing global water issues due to increased levels of nutrients. Phosphorus (P) is considered as the key nutrient and modeling P in lakes provides a valuable decision-making support tool for lake eutrophication management. During the past half a century, different hypotheses have been used for steady-state (Vollenweider-type) models of P concentration in lakes. Four main competing hypotheses are: (i) modeling P loss as a decay process in the volume of the lake vs. a sedimentation process over the area of the sediments, (ii) modeling the lake as a continuously mixed-flow reactor vs. a plug-flow reactor, and (iii) modeling P loss as a first-order reaction vs. a second-order reaction, and (iv) considering a fraction of P as fast sedimentation particles or not. We combine these hypotheses to develop 16 models. Combining a large database (n=738) from literature, we calibrate the models and compare the hypotheses of the models. The best-performing model considers the lake as a mixed-flow reactor and the P loss as a decay process over the volume of the lake. It also combines the second-order reaction hypothesis with the hypothesis that a constant fraction of P is associated with fast settling particles. Each of the hypotheses underlying the best model outperforms the competing hypotheses in the pairwise comparison of them as well.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2020
- Bibcode:
- 2020AGUFMH114.0010K
- Keywords:
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- 3322 Land/atmosphere interactions;
- ATMOSPHERIC PROCESSES;
- 0458 Limnology;
- BIOGEOSCIENCES;
- 0466 Modeling;
- BIOGEOSCIENCES;
- 1807 Climate impacts;
- HYDROLOGY