ICPRB Participation in Phase 6 Watershed Model Development

Ross Mandel Interstate Commission on the Potomac River Basin

Chesapeake Bay Program Modeling Workgroup Meeting December 11, 2013

Background

• Maryland Department of the Environment is supporting ICPRB participation in Phase 6 development

• MDE-ICPRB partnership in Phase 5: – ICPRB participation in early Phase 5 calibration effort

– Periodic review of Phase 5 development

– ICPRB assisted in development of local sediment TMDL methodology (based on P5)

– ICPRB developed nutrient local TMDLs for MDE based on Phase 5 Model

12/11/2013 2

MDE Interests in Phase 6 Watershed Model

• MDE is interested in improving the performance of the Watershed Model at calibration stations upstream of Fall Line

– Improvements in simulation at a local scale would help improve acceptance of TMDL allocations by stakeholders

– Provide sounder basis for local nutrient and sediment TMDLs and consistent baseline for environmental management

3 12/11/2013

Objectives • Regional Factors

– Incorporate regional factors into land use loading targets or mitigate their negative impacts

• Use WQ Calibration Data to Inform PQUAL Parameters

• Improve River Calibration Load Targets – Establish load targets for Western Shore, Eastern

Shore, and Lower Potomac – Investigate how Chain Bridge phosphorus loads are

related to loads in subwatersheds – Compare load targets with SPARROW

12/11/2013 4

Objectives (cont.)

• Make River Calibration Methodology Sensitive to Flow Regime

• Incorporate Local Information into Model Calibration Targets

– Local monitoring data

– Results of finer scale simulation models

– MS4 monitoring data

– Soil tests

12/11/2013 5

Using Water Quality Calibration Data to Help Set PQUAL Parameters

Ross Mandel

Interstate Commission on the Potomac Rive Basin

December 11, 2013

This work is a still exploratory. It presents a “PROOF OF CONCEPT” that

1. An analysis of water quality data can help set PQUAL parameters

2. This use of water quality data can take over the at least some of the roles of Regional Factors in the Phase 6 Watershed Model

7 12/11/2013

TOPICS

• Brief Review of How Targets and Regional Factors are set

• PQUAL parameters

• Analysis of Water Quality Calibration Data

• Linking analysis of water quality data to land segments

• How to use WQ analysis to help set PQUAL parameters

8 12/11/2013

Land Segment Targets and Regional Factors

• Land Segment Nutrient Targets – TN and TP targets based on literature review,

nutrient inputs

– Split into separate targets for baseflow, surface flow

• Regional Factors – Multiplicative factors applied to land segment

loads to calculate edge-of-stream loads

– Set in WQ calibration to improve agreement between model and ESTIMATOR loads/key WQ stations

9 12/11/2013

10 12/11/2013

11

G. Shenk 7/23/13

12/11/2013

PQUAL MODULE

• Parameters of PQUAL are concentrations associated with baseflow, interflow, surface runoff, and eroded sediment

• Parameters can be set on a monthly (seasonal) basis

• How can we set PQUAL parameters? – Targets for basflow loads

– Simulated flow (baseflow, etc.) from PWATER

– Concentration parameter = target/ simulated flow

12 12/11/2013

Using Observed Concentrations to Set PQUAL Parameters

• Simple paradigm: Suppose you are using HSPF with PQUAL to simulate

– Small watershed

– Single land use

– Single river reach

– Monitoring station at watershed outlet

• Set PQUAL baseflow concentration parameter = average observed concentration in baseflow

13 12/11/2013

Challenges to Using Observed Data to Inform PQUAL Parameters in Watershed

Model • Multiple land uses

• Nested watersheds in river network

• Not a one-to-relation between land segments and monitoring stations: multiple land segments contribute/impact multiple monitoring locations

14 12/11/2013

Analysis of Water Quality Calibration Data

Constituents TN, TP, NO3, PO4

Seasons • Spring (Mar-May) • Summer (Jun-Aug) • Fall (Sep-Nov) • Winter (Dec-Feb)

Flow Regime (percentile) • Very low (<10%) • Low (10-50%) • High (50-90%) • Very High (>90%) • Ambient (10-90%)

WQ Statistics average, maximum, 10th, 25th, 50th, 75th, and 90th percentiles

15 12/11/2013

Flow Percentiles and Flow Regime

16 12/11/2013

Flow Regime and WQ Concentration

17 12/11/2013

Seasonality of WQ Concentrations

18 12/11/2013

WQ Concentrations by Flow Regime and Season

19 12/11/2013

Geographic Analysis

• Graph bar plot of seasonal mean concentrations on map by major/minor basin

• Look for patterns of seasonal rankings, changes in concentration with watershed size

• Ambient (10-90% flow percentile) and Storm (>90th flow percentile)

• (Statistics are highly correlated, so just looked at mean)

20 12/11/2013

Ambient Mean TP Upper Potomac

GARRETT

HARDY

SOMERSET

HAMPSHIRE

LOUDOUN

FRANKLINFULTON

GRANT

FAUQUIER

FREDERICK

FAIRFAX

WASHINGTON

BERKELEY

FREDERICK

HARDYGRANT

MORGAN

BEDFORD

SHENANDOAH

ALLEGANY

CLARKE

FREDERICK

MINERAL

TUCKER

BEDFORD

JEFFERSON

ADAMS

PAGE

PENDLETON

ALLEGANY

PENDLETON

FRANKLIN

MINERAL

MONTGOMERY

ADAMS

WARREN

PRINCE WILLIAM

ROCKINGHAM

WARREN

BEDFORD

PAGERAPPAHANNOCK

Randolph

CUMBERLAND

SHENANDOAH

PRESTON

RAPPAHANNOCK

FAUQUIER

ROCKINGHAM

CARROLL

CULPEPER

MANASSAS

WINCHESTER

FAIRFAX CITY

MANASSAS PARK

FAIRFAX

FAIRFAX

PU2_3090_4050PU6_3752_4080

PU3_3290_3390

PU6_3610_3530

PU3_3860_3610

PU6_4020_3870

PU4_4310_4210

PU2_5190_4310

PU2_6050_5190

PU2_4360_4160

PU4_3890_3990

PU3_3680_3890

PU4_4440_0003

PU1_4840_4760

Ambient TP

WQ Calibration Stations

0.064

spring

Summer

Fall

Winter

21 12/11/2013 DRAFT

Ambient Mean TP Shenandoah

HAMPSHIRE

HARDY

LOUDOUN

FAUQUIER

FREDERICK

BERKELEY

PAGE

SHENANDOAH

HARDY CLARKE

MINERAL

MORGAN

JEFFERSON

FREDERICK

PRINCE WILLIAM

FAIRFAX

WARREN

WASHINGTON

FREDERICK

SHENANDOAH

ROCKINGHAM

PAGE

WARREN

RAPPAHANNOCK

MINERAL

ALLEGANY

ALLEGANY

MONTGOMERY

ROCKINGHAM

RAPPAHANNOCK

CULPEPER

FAUQUIER

GRANT

GARRETT

MANASSAS

MADISON

WINCHESTER

MANASSAS PARK

PS5_4380_4370

PS1_4790_4830

PS3_5100_5080

PS2_5560_5100

PS2_5550_5560

PS5_5240_5200

PS4_5840_5240

Ambient TP

WQ Calibration Stations

0.064

spring

Summer

Fall

Winter

22 12/11/2013 DRAFT

Ambient Mean TP Middle Potomac

YORK

LOUDOUN

CARROLL

ADAMS

BALTIMORE

FREDERICK

MONTGOMERY

WASHINGTON

FRANKLIN

BERKELEY

HOWARDFREDERICK

FULTON

CLARKE

FREDERICK

FAIRFAX

MORGAN

JEFFERSON

ANNE ARUNDEL

FAUQUIER

WARREN

FRANKLIN ADAMS

PRINCE GEORGES

BALTIMORE

WARREN

FAUQUIER

BEDFORD

DIST OF COLUMBIA

HARFORD

PRINCE WILLIAM ARLINGTON

BALTIMORE

WINCHESTER

DIST OF COLUMBIA

ALLEGANY

ANNE ARUNDEL

FALLS CHURCHANNE ARUNDEL

ANNE ARUNDEL

BALTIMORE

FAIRFAX

ARLINGTON

ANNE ARUNDEL

MONTGOMERY

ANNE ARUNDEL

DIST OF COLUMBIA DIST OF COLUMBIA

ALLEGANY

PM7_4820_0001

PM7_4820_0001

PM1_4250_4500

PM3_4670_4660

PM4_4040_0003

PM1_3120_3400

PM2_2860_3040

PM7_4200_0003PM1_4430_4200

PM1_3510_4000

Ambient TP

WQ Calibration Stations

0.064

spring

Summer

Fall

Winter

23 12/11/2013 DRAFT

Storm Mean TP Upper Potomac

GARRETT

HAMPSHIRE

HARDY

SOMERSET

LOUDOUN

GRANT

FULTON

FREDERICK

WASHINGTON

BERKELEY

FRANKLIN

GRANT HARDY

MORGAN

ALLEGANY

CLARKE

BEDFORD

MINERAL

JEFFERSON

BEDFORD

ALLEGANY

MINERAL

FAUQUIER

FRANKLIN

WARREN

TUCKER

SHENANDOAH

SHENANDOAH

FREDERICK

BEDFORD

WARRENPENDLETON

FAUQUIERPENDLETON PRINCE WILLIAM

Randolph

WINCHESTER

PRESTON

ROCKINGHAM FAIRFAX

PU2_4050_4180PU6_4080_4180

PU3_3290_3390

PU6_3530_3440

PU3_3860_3610

PU6_3870_3690

PU4_4210_4170

PU2_5190_4310

PU2_4160_3930

PU4_3990_3780

PU3_3680_3890

PU4_4440_3970

PU1_4760_4450

Storm TP

WQ Calibration Stations

0.064

spring

Summer

Fall

Winter

24 12/11/2013 DRAFT

Link WQ Calibration Stations to Land Segments through Importance

• Watershed Model already has a method for linking land segments to calibration stations in hydrology calibration: Importance

• Importance – What fraction of calibration station’s watershed is

contributed by land segment – Measures influence of land segment on station

• Calculate concentration for each land segment as average of seasonal station concentrations weighed by importance

25 12/11/2013

26 12/11/2013

YORK

Randolph

SOMERSET

Greenbrier

INDIANA

BLAIR

Pocahontas

PERRY

CAMBRIA

GARRETTPRESTON

HUNTINGDON

LANCASTER

LOUISA

FAUQUIER

BATH

AUGUSTA

FULTON

HARDY

HAMPSHIRE

ADAMS

MIFFLIN

BALTIMORE

LOUDOUN

CENTRE

TUCKER

FAIRFAX

JUNIATA

CHARLES

CAROLINE

FRANKLIN

CARROLL

ALBEMARLE

BATH

HARFORD

SCHUYLKILL

DAUPHIN

GRANT

SNYDER

ORANGE

LEBANON

FREDERICK

FREDERICK

CULPEPER

PAGE

MONTGOMERY

WASHINGTON

BERKELEY

CUMBERLAND

HOWARD

SPOTSYLVANIA

MORGAN

ALLEGANY

BERKS

MADISON

CLARKE

CLEARFIELD

ROCKBRIDGE

DAUPHIN

ALLEGHANYFLUVANNA

BEDFORD

AUGUSTA

ROCKINGHAM

ST MARYS

FRANKLINBEDFORD

BEDFORD

PENDLETON

HARDYGRANT

PENDLETON

ST MARYS

ANNE ARUNDEL

PRINCE GEORGES

TALBOT

STAFFORD

DORCHESTER

HIGHLAND

SHENANDOAH

ESSEX

CALVERT

KENT

PAGEROCKINGHAM

FREDERICK

PRINCE WILLIAM

MINERAL

KENT

ADAMS

JEFFERSON

NORTHUMBERLAND

ALLEGANY

MINERAL

HIGHLAND

CALVERT

WARREN

WESTMORELAND

CENTRE

RICHMOND

KING GEORGE

QUEEN ANNES

MADISON

SHENANDOAH

TALBOT

NELSON

ANNE ARUNDEL

AUGUSTA

RAPPAHANNOCK

WARREN

GREENE

CUMBERLAND

NELSON

CHARLES

COLUMBIAUNION

GREENE

HANOVER

ALBEMARLE

SOMERSET

BALTIMORE

UNION

WESTMORELAND

BALTIMORE

CECIL

HARFORD

RAPPAHANNOCK

ROCKINGHAM

NORTHUMBERLAND

FAUQUIER

NORTHUMBERLAND

TALBOT

KING GEORGE

KING AND QUEEN

ESSEX

DIST OF COLUMBIAARLINGTON

STAFFORD

QUEEN ANNES

ROCKBRIDGE

STAUNTON

FAIRFAX

ALEXANDRIA

HARRISONBURG

FAIRFAX

RICHMOND

WAYNESBORO

BALTIMORE

MANASSAS

DORCHESTER

PRINCE WILLIAM

WINCHESTER

FREDERICKSBURG

CHARLOTTESVILLE

FAIRFAX CITY

QUEEN ANNES

PRINCE GEORGES

CAROLINEKING GEORGE

PRINCE GEORGES

MANASSAS PARK

CHESTER

FAIRFAX

Mean Ambient TP (mg/l)

Land Segments

Fall

0.01 - 0.04

0.05 - 0.08

0.09 - 0.12

0.13 - 0.16

0.17 - 0.28

Fall Weighted Baseflow TP Concentration

27 12/11/2013 DRAFT

YORK

Randolph

SOMERSET

Greenbrier

INDIANA

BLAIR

Pocahontas

PERRY

CAMBRIA

GARRETTPRESTON

HUNTINGDON

LANCASTER

LOUISA

FAUQUIER

BATH

AUGUSTA

FULTON

HARDY

HAMPSHIRE

ADAMS

MIFFLIN

BALTIMORE

LOUDOUN

CENTRE

TUCKER

FAIRFAX

JUNIATA

CHARLES

CAROLINE

FRANKLIN

CARROLL

ALBEMARLE

BATH

HARFORD

SCHUYLKILL

DAUPHIN

GRANT

SNYDER

ORANGE

LEBANON

FREDERICK

FREDERICK

CULPEPER

PAGE

MONTGOMERY

WASHINGTON

BERKELEY

CUMBERLAND

HOWARD

SPOTSYLVANIA

MORGAN

ALLEGANY

BERKS

MADISON

CLARKE

CLEARFIELD

ROCKBRIDGE

DAUPHIN

ALLEGHANYFLUVANNA

BEDFORD

AUGUSTA

ROCKINGHAM

ST MARYS

FRANKLINBEDFORD

BEDFORD

PENDLETON

HARDYGRANT

PENDLETON

ST MARYS

ANNE ARUNDEL

PRINCE GEORGES

TALBOT

STAFFORD

DORCHESTER

HIGHLAND

SHENANDOAH

ESSEX

CALVERT

KENT

PAGEROCKINGHAM

FREDERICK

PRINCE WILLIAM

MINERAL

KENT

ADAMS

JEFFERSON

NORTHUMBERLAND

ALLEGANY

MINERAL

HIGHLAND

CALVERT

WARREN

WESTMORELAND

CENTRE

RICHMOND

KING GEORGE

QUEEN ANNES

MADISON

SHENANDOAH

TALBOT

NELSON

ANNE ARUNDEL

AUGUSTA

RAPPAHANNOCK

WARREN

GREENE

CUMBERLAND

NELSON

CHARLES

COLUMBIAUNION

GREENE

HANOVER

ALBEMARLE

SOMERSET

BALTIMORE

UNION

WESTMORELAND

BALTIMORE

CECIL

HARFORD

RAPPAHANNOCK

ROCKINGHAM

NORTHUMBERLAND

FAUQUIER

NORTHUMBERLAND

TALBOT

KING GEORGE

KING AND QUEEN

ESSEX

DIST OF COLUMBIAARLINGTON

STAFFORD

QUEEN ANNES

ROCKBRIDGE

STAUNTON

FAIRFAX

ALEXANDRIA

HARRISONBURG

FAIRFAX

RICHMOND

WAYNESBORO

BALTIMORE

MANASSAS

DORCHESTER

PRINCE WILLIAM

WINCHESTER

FREDERICKSBURG

CHARLOTTESVILLE

FAIRFAX CITY

QUEEN ANNES

PRINCE GEORGES

CAROLINEKING GEORGE

PRINCE GEORGES

MANASSAS PARK

CHESTER

FAIRFAX

Mean Ambient TP (mg/l)

Land Segments

Winter

0.03 - 0.04

0.05 - 0.08

0.09 - 0.12

0.13 - 0.16

0.17 - 0.25

Winter Weighted Baseflow TP Concentration

28 12/11/2013 DRAFT

YORK

Randolph

SOMERSET

Greenbrier

INDIANA

BLAIR

Pocahontas

PERRY

CAMBRIA

GARRETTPRESTON

HUNTINGDON

LANCASTER

LOUISA

FAUQUIER

BATH

AUGUSTA

FULTON

HARDY

HAMPSHIRE

ADAMS

MIFFLIN

BALTIMORE

LOUDOUN

CENTRE

TUCKER

FAIRFAX

JUNIATA

CHARLES

CAROLINE

FRANKLIN

CARROLL

ALBEMARLE

BATH

HARFORD

SCHUYLKILL

DAUPHIN

GRANT

SNYDER

ORANGE

LEBANON

FREDERICK

FREDERICK

CULPEPER

PAGE

MONTGOMERY

WASHINGTON

BERKELEY

CUMBERLAND

HOWARD

SPOTSYLVANIA

MORGAN

ALLEGANY

BERKS

MADISON

CLARKE

CLEARFIELD

ROCKBRIDGE

DAUPHIN

ALLEGHANYFLUVANNA

BEDFORD

AUGUSTA

ROCKINGHAM

ST MARYS

FRANKLINBEDFORD

BEDFORD

PENDLETON

HARDYGRANT

PENDLETON

ST MARYS

ANNE ARUNDEL

PRINCE GEORGES

TALBOT

STAFFORD

DORCHESTER

HIGHLAND

SHENANDOAH

ESSEX

CALVERT

KENT

PAGEROCKINGHAM

FREDERICK

PRINCE WILLIAM

MINERAL

KENT

ADAMS

JEFFERSON

NORTHUMBERLAND

ALLEGANY

MINERAL

HIGHLAND

CALVERT

WARREN

WESTMORELAND

CENTRE

RICHMOND

KING GEORGE

QUEEN ANNES

MADISON

SHENANDOAH

TALBOT

NELSON

ANNE ARUNDEL

AUGUSTA

RAPPAHANNOCK

WARREN

GREENE

CUMBERLAND

NELSON

CHARLES

COLUMBIAUNION

GREENE

HANOVER

ALBEMARLE

SOMERSET

BALTIMORE

UNION

WESTMORELAND

BALTIMORE

CECIL

HARFORD

RAPPAHANNOCK

ROCKINGHAM

NORTHUMBERLAND

FAUQUIER

NORTHUMBERLAND

TALBOT

KING GEORGE

KING AND QUEEN

ESSEX

DIST OF COLUMBIAARLINGTON

STAFFORD

QUEEN ANNES

ROCKBRIDGE

STAUNTON

FAIRFAX

ALEXANDRIA

HARRISONBURG

FAIRFAX

RICHMOND

WAYNESBORO

BALTIMORE

MANASSAS

DORCHESTER

PRINCE WILLIAM

WINCHESTER

FREDERICKSBURG

CHARLOTTESVILLE

FAIRFAX CITY

QUEEN ANNES

PRINCE GEORGES

CAROLINEKING GEORGE

PRINCE GEORGES

MANASSAS PARK

CHESTER

FAIRFAX

Mean Ambient TP (mg/l)

Land Segments

Spring

0.01 - 0.03

0.04 - 0.06

0.07 - 0.09

0.10 - 0.12

0.13 - 0.18

Spring Weighted Baseflow TP Concentration

29 12/11/2013 DRAFT

YORK

Randolph

SOMERSET

Greenbrier

INDIANA

BLAIR

Pocahontas

PERRY

CAMBRIA

GARRETTPRESTON

HUNTINGDON

LANCASTER

LOUISA

FAUQUIER

BATH

AUGUSTA

FULTON

HARDY

HAMPSHIRE

ADAMS

MIFFLIN

BALTIMORE

LOUDOUN

CENTRE

TUCKER

FAIRFAX

JUNIATA

CHARLES

CAROLINE

FRANKLIN

CARROLL

ALBEMARLE

BATH

HARFORD

SCHUYLKILL

DAUPHIN

GRANT

SNYDER

ORANGE

LEBANON

FREDERICK

FREDERICK

CULPEPER

PAGE

MONTGOMERY

WASHINGTON

BERKELEY

CUMBERLAND

HOWARD

SPOTSYLVANIA

MORGAN

ALLEGANY

BERKS

MADISON

CLARKE

CLEARFIELD

ROCKBRIDGE

DAUPHIN

ALLEGHANYFLUVANNA

BEDFORD

AUGUSTA

ROCKINGHAM

ST MARYS

FRANKLINBEDFORD

BEDFORD

PENDLETON

HARDYGRANT

PENDLETON

ST MARYS

ANNE ARUNDEL

PRINCE GEORGES

TALBOT

STAFFORD

DORCHESTER

HIGHLAND

SHENANDOAH

ESSEX

CALVERT

KENT

PAGEROCKINGHAM

FREDERICK

PRINCE WILLIAM

MINERAL

KENT

ADAMS

JEFFERSON

NORTHUMBERLAND

ALLEGANY

MINERAL

HIGHLAND

CALVERT

WARREN

WESTMORELAND

CENTRE

RICHMOND

KING GEORGE

QUEEN ANNES

MADISON

SHENANDOAH

TALBOT

NELSON

ANNE ARUNDEL

AUGUSTA

RAPPAHANNOCK

WARREN

GREENE

CUMBERLAND

NELSON

CHARLES

COLUMBIAUNION

GREENE

HANOVER

ALBEMARLE

SOMERSET

BALTIMORE

UNION

WESTMORELAND

BALTIMORE

CECIL

HARFORD

RAPPAHANNOCK

ROCKINGHAM

NORTHUMBERLAND

FAUQUIER

NORTHUMBERLAND

TALBOT

KING GEORGE

KING AND QUEEN

ESSEX

DIST OF COLUMBIAARLINGTON

STAFFORD

QUEEN ANNES

ROCKBRIDGE

STAUNTON

FAIRFAX

ALEXANDRIA

HARRISONBURG

FAIRFAX

RICHMOND

WAYNESBORO

BALTIMORE

MANASSAS

DORCHESTER

PRINCE WILLIAM

WINCHESTER

FREDERICKSBURG

CHARLOTTESVILLE

FAIRFAX CITY

QUEEN ANNES

PRINCE GEORGES

CAROLINEKING GEORGE

PRINCE GEORGES

MANASSAS PARK

CHESTER

FAIRFAX

Mean Ambient TP (mg/l)

Land Segments

Summer

0.03 - 0.04

0.05 - 0.08

0.09 - 0.12

0.13 - 0.18

0.19 - 0.25

Summer Weighted Baseflow TP Concentration

30 12/11/2013 DRAFT

Using Weighted Concentrations to Modify LU PQUAL Parameters

• Weighted Seasonal Concentration *Baseflow = Contribution of Land Segment to baseflow load (on seasonal basis)

• Modify initial PQUAL baseflow concentration parameters so anticipated baseflow load matches load based on weighted seasonal concentrations

• Assume same correction factor for each land use

31 12/11/2013

C = observed (seasonal) baseflow concentration (as weighted by station importance) Coi = original baseflow concentration parameter for LUi Cri = revised baseflow concentration parameter for LUi Ai = area of LUi Bi =baseflow volume from LUi a = Correction factor

Basic Assumption: C ∗ Ai ∗ Bi = a ∗ Coi ∗ Ai ∗ Bi

Solving for a: 𝑎 = 𝐶 ∗

𝐴𝑖 ∗ 𝐵𝑖 𝐶𝑜𝑖 ∗ 𝐴𝑖 ∗ 𝐵𝑖

Assume Bi ‘s same, to simplify: 𝑎 = 𝐶 ∗

𝐴𝑖 𝐶𝑜𝑖 ∗ 𝐴𝑖

32 12/11/2013

(Test) Adjustment Factor for PO4

33

SOMERSET

PERRY

GARRETTPRESTON

FAUQUIER

AUGUSTA

FULTON

HARDY

HAMPSHIRE

ADAMS

LOUDOUN

TUCKER

FAIRFAX

FRANKLIN

CARROLL

GRANTFREDERICK

FREDERICK

PAGE

MONTGOMERY

WASHINGTON

BERKELEY

MORGAN

ALLEGANY

CLARKE

BEDFORD

AUGUSTA

ROCKINGHAM

FRANKLINBEDFORD

BEDFORD

PENDLETON

HARDYGRANT

PENDLETON

HIGHLAND

SHENANDOAH

PAGEROCKINGHAM

FREDERICKMINERAL

ADAMS

JEFFERSON

ALLEGANY

MINERAL

HIGHLAND

WARRENSHENANDOAH

AUGUSTA

WARREN

CUMBERLAND

ROCKINGHAM

FAUQUIER DIST OF COLUMBIA

STAUNTON

FAIRFAX

HARRISONBURG

FAIRFAX

WAYNESBORO

DIST OF COLUMBIA

WINCHESTER

DIST OF COLUMBIA

FAIRFAX

Baseflow PO4 Adjustment Factor

Land Segments

SumOfcombo

0.0038 - 0.063

0.063 - 0.178

0.178- 0.372

0.372 - 0.726

0.726 - 1.69

12/11/2013 DRAFT:Based on P52

P532 TP Regional Factors

Regional Factors

River Segments

TP

0.731

1.392

1.392 - 1.44

1.44- 1.463

1.463 - 1.659

34 12/11/2013

Advantages over Regional Factors

• Targeted use of WQ data to modify land segment loads

• Modifications can be applied to land simulation targets outside of river calibration

35 12/11/2013

Issues

• Which statistics to use

• Alternative methods of weighing land uses

• Can method be applied to other PQUAL parameters (interflow)

• Take into account point source influence

• ???

36 12/11/2013

Contact Information

Ross Mandel

Interstate Commission on the Potomac River Basin

rmandel@icprb.org