Maumee Basin SWAT Modeling Todd Redder Joseph V. DePinto Chelsie Boles

University of Michigan Water Center WBLE Scenario Workshop June 23, 2015

Presentation Outline • Summary of LimnoTech modeling activities in WBLE

• Overview of Maumee SWAT model

• Maumee SWAT calibration: – “Goodness of fit” calibration statistics (flow, pollutant loads) – Additional model-data comparisons (e.g., tile flow, crop yield)

• SWAT scenario evaluation: – Review SWAT scenario capabilities – Examples of past SWAT scenario applications & results

Relevant Modeling Activities in WBLE • Watershed Modeling:

– Blanchard River – AnnAGNPS (USACE, 2009-10) – Tiffin River – SWAT (USACE, 2011-12)

Ephemeral gully erosion represented Farmer reverse auctions – cover crops, filter strips, tile

drain management – Maumee SWAT modeling (2011-present)

Preliminary evaluation of “upscaled” BMPs (GLPF) - e.g., cover crops, conservation tillage

“4R” nutrient management evaluation (IPNI)

• “Western Lake Erie Ecosystem Model” (WLEEM) – Simulates nutrient transport & fate, harmful algal

bloom (HABs) – Various funding sources - recently applied for Annex 4

SWAT Model – Code Enhancements • Incorporated “tillage-induced ephemeral gully

erosion” sub-model • Enhanced model algorithms for representing

detention basins / wetlands: – “Potholes” (HRU level) – “Ponds” (subbasin level)

• Phosphorus in tile drains: – Fixed “disconnection” issue for soluble reactive P (SRP) – Added option for specifying fixed SRP concentration in

tiles

• Model calibration & diagnostic support: – Added many diagnostic variables (e.g., tile flow,

NO3/SRP concentrations) – Comprehensive post-processing & visualization tools

SWAT Custom Visualization Tools

Purpose/Role of Maumee SWAT Model Implementation of Nutrient

Management Practices • Type of practice(s) • Affected land area

Soil & Water Assessment Tool

(SWAT)

Western Lake Erie Ecosystem Model

(WLEEM)

e.g., changes to fertilizer timing, quantity

Flow, sediment, nutrient loading near mouth

Flow

, sed

imen

t, nu

trie

nt lo

adin

g Reduced Nutrient & Sediment Delivery

(@ tributary mouths)

Reduced Harmful Algal Production in

Western Lake Erie • Microsystis bloom intensity • Microsystis bloom duration

Ecological Endpoints

Model Linkage

Maumee Basin SWAT Model – Subbasin Delineation

Tiffin

Tiffin

Lower Maumee

Blanchard

St. Marys

St. Joseph

Upper Auglaize

Lower Auglaize

Upper Maumee

Flow Sediment Nutrients

Western Lake Erie

Basin Michigan Ohio

Subbasin Count: 203 HRU Count: 2,341

Maumee SWAT Model Lineage • Based on original EcoFore SWAT model (Bosch et al. 2011):

– Subbasin delineation roughly based on HUC-12 delineation – Simulation time period: 1995-2005

• Key LimnoTech refinements include: – SWAT 2012 framework adopted (updated from SWAT 2005) – Simulation period updated to 1995-2010 – Incorporation of detailed cropland management input data

from ARS Maumee CEAP SWAT model – Preliminary representation of soluble reactive P (SRP) transport

through tile drains

Hydrology Calibration Metrics

• Model originally calibrated to Waterville stations: USGS gage: 04193500 Heidelberg monitoring

(sediment, nutrients)

• Additional stations to monitor model fit for tributary branches and stations upstream of Waterville

• At least one station on each major tributary considered for flow calibration

Model Calibration Locations Tiffin River

@ Stryker

Maumee R. @ Waterville

Blanchard R. @ Findlay

Model Calibration: Metrics & Monthly Targets

Moriasi, D. N., J. G. Arnold, M. W. Van Liew, R. L. Bingner, R. D. Harmel, and T. L. Veith. 2007. “Model Evaluation Guidelines for Systematic Quantification of Accuracy in Watershed Simulations.” Transactions of the ASABE 50 (3): 885–900.

• All stations meet the standards confirming at least a “Satisfactory” calibration for monthly guidelines

• Most stations meet the “Very Good” guidelines for monthly NSE

• No Moriasi et al., 2007 standards given for R2, but statistic is greater than 0.50 for all locations

Note: Daily PBIAS values equal monthly PBIAS values.

Flow Calibration Statistics

Hydrograph Comparisons @ Waterville Water Year 2005

Water Year 2009

Water Budget for Entire Maumee Basin

Tile Drainage (as % of precipitation): • Target range: 10-31% (mean: ~21%)

• Model: ~19% on tile-drained land

Tile Flow by HUC-8 Watershed

Water Quality Calibration Metrics

Landscape Nutrient Yields

12.9

1.6

0.67

14.7

1.3

0.65

0

1

10

100

TN, lb/acre TP, lb/acre Sediment, tons/acre

Unit-

Area

Loa

d, lo

g sc

ale

Average Landscape Loading, Agriculture

Literature Average Maumee SWAT

Tile Drainage: Dissolved Nutrients

0

0.01

0.02

0.03

0.04

0.05

0.06

SRP

Tile

SRP

Conc

entra

tion,

mg/

L

SRP in Tile Drainage

0

5

10

15

20

25

NO3

Tile

NO3 C

once

ntra

tion,

mg/

L

NO3 in Tile Drainage

Observed Range: ~ 0.01 – 1.0 mg/L (K. King, OSU)

• Simulated NO3 loading of 21.15 kg/ha for tile-drained AGRR lands.

• Compares favorably with 23.17 kg/ha measured by Kladivko et al., 2004 for Indiana

Crop Yield Comparison (2000 – 2005)

020406080

100120140160180

2000 2001 2002 2003 2004 2005

YIEL

D (B

U/ac

re)

CORN YIELDS MAUMEE SWAT NASS

0

10

20

30

40

50

60

70

2000 2001 2002 2003 2004 2005

YIEL

D (B

U/ac

re)

SOYBEAN YIELDS MAUMEE SWAT NASS

Nutrient & Sediment Calibration Metrics • All stations meet the standards

confirming at least a “Satisfactory” calibration for monthly guidelines for nitrogen and phosphorus constituents.

• Most stations meet the “Very Good” guidelines for PBIAS (Abs(PBIAS) < 25)

• Monthly sediment loads at Waterville are just outside the “Satisfactory” range (±55)

Note: Instream sediment calibration has no influence on nutrients

All values reported are on a monthly time-step

Monthly TP Load @Waterville (1998-2010)

Monthly TN Load @Waterville (1998-2010)

“Spring” P Loads: Feeding Harmful Algal Bloom Production (Waterville)

1:1 Line

R2: 0.78 NSE: 0.62 (Good / Satisfactory) PBIAS: -10.6 (Very Good)

Maumee SWAT: Evaluating Nutrient Management Scenarios

SWAT General Management Capabilities • One or multiple rotation years (Maumee SWAT: 4 years) • Daily scheduling of crop land management practices:

– Crop planting – Crop harvest (or “kill”) – Tillage – Fertilizer application (timing, amount, degree of incorporation)

• ‘Direct’ implementation of some BMPs – e.g.: – Conservation tillage / ‘no till’ – Filter strips/buffers – Nutrient management – Conservation crop rotation – Wetland / detention basin treatment of ag runoff

Example SWAT BMP Evaluations • Little Cannon (MN) SWAT model:

– Simulate “detention pond” treatment of 30% of agricultural land (23% TP reduction, 3% TN reduction)

• Tiffin River SWAT model: – Support MSU reverse auction (Defiance, Fulton counties) – Ranking of farmer bids based on proposed cover crops, filter

strips, drain water mgmt. • Maumee Basin SWAT model:

– Preliminary demonstration of nutrient management (rate, incorporation)

Example Results: single HRU, various BMPs (previous version of Maumee Basin SWAT model)

General Considerations for BMP Implementation in SWAT

• Suitability/robustness of SWAT & supporting data:

– “Direct” vs. “indirect” representation – How critical is local topography to

representing a BMP realistically?

• Extent of implementation across watershed – e.g.:

– 25% of cropland acres – 40% of cropland acres

• Prioritization of implementation: – Randomly distributed implementation, or: – Targeting of higher sediment/nutrient yield

areas

Questions?

Contact Information: Todd Redder LimnoTech Ann Arbor, MI Email: tredder@limno.com Phone: 734-332-1200

Funding Acknowledgements: • Great Lakes Protection Fund • International Plant Nutrition Institute (IPNI):

4R Nutrient Stewardship Research Fund