The Antecedent Moisture Model

Antecedent Moisture Model (AMM) Overview

Rainfall-runoff dynamics of surface water, combined sewer, and separate sewer systems can be highly impacted by antecedent moisture conditions, or the relative wetness or dryness of the system. Accurately simulating these dynamics is critical for developing predictive models of systems that are sensitive to antecedent moisture. This page presents the results of 25 years of work formulating, applying and refining a hydrologic model that addresses the impacts of antecedent moisture conditions on the rainfall-runoff process. Here is an blog post article with an introduction to antecedent moisture and an overview of the antecedent moisture model.

Tutorial Videos on the H2Ometrics Antecedent Moisture Model

  • AMM Overview – Presents an overview of the Antecedent Moisture Model.

  • Diurnal Dynamic Model – Filter to separate the diurnal pattern from the I&I and GWI flow.

  • Computing the I/I Flow – Subtracting the diurnal pattern from the total flow to generate the I&I and GWI flow.

  • Linear Model – Introduction to the linear unit hydrograph model used as the base of the AMM.

  • Antecedent Moisture Effects – Overview of how antecedent moisture effects typically effects rainfall-runoff processes.

  • AM Retention Factor – This parameter adjusts the memory of preceding rains and their impact on flows.

  • Temperature Factor – This parameter adjusts the temperature effects on antecedent moisture to model season impacts.

  • Exporting Parameters – Overview of how to export AMM parameters to a CSV file.

  • Settings – Overview of the settings for the AMM.

  • Units – How to change the units of the AMM flow output.

  • Base Flow Model – Overview of the base flow model for constant flow and GWI flow,

  • AOF Metrics – Accuracy of ft metric tools.

  • AOF Plots – Accuracy of fit PDF output plots. 

  • AMM Sums Model – Unified interface for adding model components (base flow, inflow, infiltration), editing models, and viewing AOF metrics.

  • Frequency Analysis Tool – Overview of frequency tools that generates annual maxima series from long term continuous simulations for design.