Water quality treatment in bioretention systems has been revised for use in music v5. More emphasis is placed on the continuity of explanatory variables which are in principle continuous, and the analysis is based on a multiple regression approach. Additional data has been brought in from the original data files of the three column studies where appropriate under the new methodology.
Total Suspended Solids
Modelled outflow TSS concentration depends on the soil moisture at the start of the event (continuous variable) and the vegetation type (categorical variable), as shown below.
In spreadsheet terminology the modelled outflow TSS concentration from effectively vegetated filters is: 1.27 - 1.96 * LN(MAX(SoilMoisture, 0.09))
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- The previous TSS treatment calculations used the proportion of organic material in filter, which was entered by the user in the bioretention properties dialog box. This is no longer required, so the question could now be removed from the dialog box.
Total Phosphorus
Outflow TP concentration depends on the orthophosphate content of the filter medium, the depth of a submerged zone (if present), the filter soil moisture content at the start of the event (all continuous variables), and the vegetation type (categorical variable).
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Here are some sample modelled outflow TP concentrations.
Total Nitrogen
Outflow TN concentration depends on the total nitrogen content of the filter medium, the total nitrogen concentration of the inflow, the filter soil moisture content at the start of the event (all continuous variables), and the vegetation type (categorical variable).
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Here are some sample modelled outflow TN concentrations.
