Purdue Status Report Summer Meeting 2012 Midwest Spatial Decision Support Interest Group Region 5...

Purdue Status Report

Summer Meeting 2012

Midwest Spatial Decision Support Interest Group

Region 5 EPA

July 9, 2012

Bernie Engel, Larry Theller, Youn Shik Park, Laurent Ahiablame. Agricultural and Biological Engineering

Purdue University

Topics• L-THIA LID improvements

• Fox River Project update (L-THIA Owls)

Effectiveness of low impact development practices in two urbanized watersheds:

Retrofitting with rain barrels/cisterns and porous pavements

Laurent Ahiablame

Prof. Bernard Engel, Prof. Indrajeet Chaubey

4

How effective are LID practices at the watershed scale? LID practices - lot level control measures

Current focus of research – runoff management with LID practices. Impacts of LID practices on baseflow need to be investigated

at the lot scale at the watershed scale

The Problem

How to Proceed? Monitoring – most appropriate (perhaps),

expensive, time consuming, sometimes impossible.

Modeling – convenient, less expensive, time efficient, sometimes may be complex.

Modeling – L-THIA-LID

L-THIA Modeling of LID Practices

Standard procedure for LID modeling Representation of LID practices

CN values Consideration of design guidelines

Sizing factors Computation of runoff, baseflow, total flow

Threshold area: IF watershed area ≥ 120 ha => baseflow Computation of LID effectiveness index

Baseflow core equation Regression model for Indiana conditions

Relationship between baseflow and LID practice

BFI versus CN

Baseflow pollutant coefficients

Improving L-THIA-LID

LID practices currently represented in L-THIA-LID Bioretention/rain garden Open wooded space Porous pavement Swale Porous pavement + swale Permeable patio Green roof Disconnected impervious surfaces

Improving L-THIA-LID

L-THIA-LID Interface (VBA)

Runoff (distributed approach)2( 0.2 )

( 0.8 )

P S

QP S

P Ia

0Q P Ia

Baseflow0.953 1.424 1.26029.896bQ BDA APCP BFI

LID Effectiveness Index

100 NoLID LID

NoLID

LID

Q QEI

Q

142.100726.0 CNBFI

Little Eagle creek

Little Buck creek

  Little Eagle Creek   Little Buck CreekLand use Area (ha) Percent   Area (ha) PercentLow Density Residential 3872.8 54.8 3273.0 74.1Commercial/Industrial 2260.2 32.0 538.9 12.2High Density Residential 271.0 3.8 1.4 0.0Road/Street 573.6 8.1 366.3 8.3Bare soil 16.0 0.2 - -Grass/Pasture 77.4 1.1 238.2 5.4Total 7070.9   4417.7  

Scenario DescriptionS1 existing conditionS2 25% rain barrel/cisternS3 50% rain barrel/cisternS4 25% porous pavementS5 50% porous pavementS6 S2 + S4

Little Eagle Creek  Flow (%) TP (%) TN (%)Runoff

Scenario 2 6 5 6

Scenario 3 11 11 12

Scenario 4 3 3 3

Scenario 5 5 5 6

Scenario 6 8 8 9Baseflow

Scenario 2 -1 -1 -1

Scenario 3 -2 -2 -2

Scenario 4 -1 -1 -1

Scenario 5 -1 -1 -1

Scenario 6 -2 -2 -2Total flow

Scenario 2 2 5 3

Scenario 3 5 9 6

Scenario 4 1 2 1

Scenario 5 2 4 3

Scenario 6 4 7 5

LID Scenario Runs: 1991-2010 Effectiveness of LID practices

Little Buck Creek  Flow (%) TP (%) TN (%)Runoff

Scenario 2 3 2 3

Scenario 3 5 5 6

Scenario 4 4 4 4

Scenario 5 8 7 8

Scenario 6 7 6 7Baseflow

Scenario 2 0 0 0

Scenario 3 -1 -1 -1

Scenario 4 -1 -1 -1

Scenario 5 -1 -1 -1

Scenario 6 -1 -1 -1Total flow

Scenario 2 1 2 1

Scenario 3 2 4 3

Scenario 4 2 3 2

Scenario 5 4 6 4

Scenario 6 3 5 3

Effectiveness of LID practices LID Scenario Runs: 1991-2010

Summary Simulated runoff, baseflow, and total flow for the

baseline compared well with observed values during calibration and validation periods. Calibration: R2 and NSE > 0.5 Validation: R2 > 0.4; NSE > 0.3

Effectiveness of LID practices at the watershed scale Runoff + pollutants: 2 to 12% Baseflow + pollutants: -1 to -2% Total flow + pollutants: 1 to 9%

Good LID options for retrofitting in urbanized watershed 25% rain barrel/cistern adoption 25% porous pavement adoption 25% rain barrel/cistern + 25% of porous pavement adoption

“Fox River” Project

• Corps 516(e) project is collaboration with Michigan State University Institute of Water Research.

• Tools work together behind the interface.• High-resolution data for 4 Priority

Watersheds.• Medium-resolution data for entire Great

Lakes area.

Extends L-THIA online tool to entire Great Lakes area.

Floating, semi-transparent toolbars, collapsible menus, open architecture for partners, improved editing performance.New Area of Interest tool : Polygon

“Select by HUC” to use a single HUC 12, 10, 8 outline.

Tool will now allow use of a polygon as an area of analysis.

This will improve ability to model zoning and LID BMP areas.

-Display of HIT target layers-EPA Waters layers-GIS layers-Multi-resolution data layers

New Results Options