T/CSES 04-2019 Lake algal control process water quality target management technical guidelines multi-threshold analysis filter trajectory method for lake nutrients

Scope

The main technical content: The filtering trajectory nutrient calibration is a strong time-series segmented calibration, which emphasizes the dependence on recent paths, that is, the calibration containing time-series information: using historical data to determine the "enrichment and impoverishment path" of CHLa-TP(TN); using and selecting the inflection points of CHLa-TP trajectories for filtering trajectory segmented calibration, and using the path-dependent characteristics (the inflection points can generally be sustained for several years after that) to achieve certain forecasting functions, which can provide guidance for recent pollution control. Multi-stage calibration can achieve "one lake, multiple standards", enabling management to adopt different standard values of major limiting nutrients under different background environmental factors. Using the starting point of historical data, various inflection points, and end points, we can establish a multi-segment correlation relationship of CHLa-TP (for a more obvious original path regression, only one correlation relationship is needed). The specific methods can be divided into: 1. Parametric method: using various segment data to conduct trend line fitting with multiple functions, and selecting the function line with the largest coefficient of determination R as the calibration curve. 2. Non-parametric method: directly using the filtered phase space trajectories of CHLa-TP as the trend line fitting line as the calibration curve.

Development Information

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