A dynamic model to predict suspended particulate matter in lakes

A dynamic model for predictions of suspended particulate matter (SPM) in lake water is presented. The model includes compartments for surface water, deep water and sediment areas of erosion/transportation. SPM pathways include tributary inflow, autochthonous production, outflow via rivers, sedimentation on erosion/transportation areas, sedimentation on accumulation areas, resuspension, mineralization and mixing. The model is driven by easily accessible lake variables, including morphometric parameters (like mean depth and lake area), climatic variables (like mean monthly wind from meteorological tables) and phosphorus inflow (from measurements or monitoring programs). The model has been tested against empirical data from a number of European lakes, with generally close agreement to empirical data. Uncertainty and sensitivity tests are performed to identify the most important model uncertainties. The difficulties in quantifying allochthonous and autochthonous SPM generation far outrank the problems associated with internal processes like, e.g. sedimentation and mineralization.