03 — Cross-Correlation Lag Analysis
Computes pre-whitened cross-correlation between rainfall/snowmelt and sewer flow for each plant, identifies dominant lag signatures, and classifies plants as inflow-dominated, infiltration-dominated, or mixed.
cross-correlation lag-analysis pre-whitening arima i-and-i-classification
Pythonpandasnumpystatsmodelsscipymatplotlibseaborn
Key Findings
- ● Pre-whitening removes autocorrelation artifacts that inflate raw CCF peaks — essential for accurate lag identification
- ● Inflow-dominated plants show sharp CCF peaks at 1-3 hour lag; infiltration-dominated show broad peaks at 24-48 hours
- ● Snowmelt-flow CCF reveals different lag characteristics than rainfall-flow CCF, with broader, more sustained correlation