Patapsco back river swmm model
This presentation is the property of its rightful owner.
Sponsored Links
1 / 24

Patapsco/Back River SWMM Model PowerPoint PPT Presentation


  • 77 Views
  • Uploaded on
  • Presentation posted in: General

Patapsco/Back River SWMM Model. Part II – SWMM Water Quality Calibration Maryland Department of the Environment. Water Quality Calibration. General Aggregate Five Subwatersheds Focus on predominant land uses Calibrate EOS loads to literature values

Download Presentation

Patapsco/Back River SWMM Model

An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -

Presentation Transcript


Patapsco back river swmm model

Patapsco/Back River SWMM Model

Part II – SWMM Water Quality Calibration

Maryland Department of the Environment


Water quality calibration

Water Quality Calibration

  • General

    • Aggregate Five Subwatersheds

    • Focus on predominant land uses

    • Calibrate EOS loads to literature values

    • Calibrate Event Mean Concentrations

  • Detailed

    • Time series overlay

    • Comparative Analysis


Water quality calibration urban tss and metals

Water Quality CalibrationUrban TSS and Metals

  • Objective

    • EMC (statistics of wet-weather events)

    • Unit Load (annual)

  • Parameters

    • Buildup Rate (Linear - Calibrated)

    • Build Limit (Set high)

    • Wash-off Coefficient (Based on Literature)

    • Wash-off Exponent (Based on Literature)

  • Calculation

    • Load =  (Flow*Conc.)

    • EMC = Load /  Flow

  • Results

    • Unique Solution of Buildup Rate

  • Validation

    • Timeseries Comparision


Water quality calibration non urban land use usle

Water Quality Calibration Non-Urban Land Use (USLE)

  • Calibration Objective

    • Correlate with long term loading rate estimates

  • USLE – Estimates gross long term erosion rate

    • Parameters (Land use specific)

      R=Rainfall Energy (from BWI)

      K=Soil Erodibility (Soil type)

      LS=Slope Length Gradient Ratio (DEM)

      C=Cropping Management Factor (Landuse – Calibrated)

      P=Erosion Control Practice (Literature)

  • Delivery Ratio

    • Applied Based on Subwatershed Drainage to Baltimore Harbor

  • Parameter

    • Adjusted cropping management factor within recommended values


Event mean concentration references

Event Mean Concentration References


Unit load references

Unit Load References


Water quality data

Water Quality Data

*All data collected by Baltimore City

-DNR Core station TSS data available at stations 240, 230 and 211

(Data set contains mostly base flow samples)

- Metals values not shown from 2/25/95 to 12/1/96 due to high detection

limits


Swmm baseflow concentration

SWMM Baseflow Concentration

References

Base Flow Data Source

TSS

Cr

Zn

Pb

Baltimore County NPDES Report (2000)

X

Baltimore City NPDES Report (2001)

X

Baltimore City Wastewater Facilities Master Plan (1997)

X

X

X

Baltimore County DEPRM Watershed Monitoring Project (1997-2000)

X

MDE Upper Western Shore Monitoring Project (2001)

X

Concentrations


Results

Results


Jones falls

Jones Falls


Patapsco

Patapsco


Back river

Back River


Best management practices bmps

Best Management Practices (BMPs)

  • Uncertainty and variability in EMC

    • Instream sites from NPDES Report

  • Timeseries comparison of model vs data show reasonable concentration magnitude agreement

  • BMPs not explicitly included in model

  • Established a baseline load scenario


Sub watershed loads

Sub-Watershed Loads


Baltimore harbor watershed land use loading summary

Baltimore Harbor Watershed Land Use Loading Summary

CBP TSS Results (93-97)

Urban: 44.5%

Crop: 28.4%

Pasture: 4.1%

Forest: 23.1%


Comparative analysis existing studies

Comparative Analysis - Existing Studies


Swmm calibration summary conclusions

SWMM Calibration Summary & Conclusions

  • Focus on predominant land use for model calibration

  • Calibrate EOS loads to mean literature values

  • Calibration urban EMC’s to reported mean landuse values

  • Overlay model with water quality timeseries data

  • Comparative Analysis

  • Model supports overall trends (Flow, TSS and metals)

  • Next - Sensitivity of water quality model to NPS Loads


  • Login