Introduction to i-Tree Eco and i-Tree Hydro:
Tools to capture the role of trees in
stormwater management
Jason Henning PhD
i-Tree is a
Cooperative
Initiative
i-Tree…
“Putting USFS Urban Forest science into the hands of users”
• Based on USDA FS peerreviewed science
• Public domain software
(free)
• Accessible
• Continuously improved
www.itreetools.org
i-Tree is a
Cooperative
Initiative
among these
The 2015 i-Tree suite of tools
Web-based,
run in your
browser
Landscape
Installed on a
Windows
desktop/laptop
i-Tree is a
Cooperative
Initiative
among these
The basic science of i-Tree Eco
• Measure variables to estimate foliage
volume and wood volume
• Estimate tree leaf area using species
specific equations
• Estimate benefits largely based on
leaf area interactions with local
weather and air pollution
• Summarize structure, function, value
i-Tree is a
Cooperative
Initiative
among these
i-Tree Eco: Single tree example
River birch
3 stems (3”, 2” and 2”)
15 ft total height
5 ft crown base height
12 feet crown width E/W
11 feet crown width N/S
0% die back
3% missing
Eastern white pine
White pine has
5x the leaf
surface area and
accounts for 8x
the avoided
runoff
1 stem (7”)
26 ft total height
2 ft crown base
18 feet crown width E/W
20 feet crown width N/S
0% die back
13% missing
i-Tree is a
Cooperative
Initiative
among these
i-Tree Eco: Municipal/Community example
Land Use
Commercial
Community Service
Industrial
Recreation
Residential
Vacant
Wooded
Total
Tree Number
8,529
7,454
625
2,799
33,587
14,342
52,838
120,174
Leaf Area
Avoided
Avoided Runoff
Value ($)
(km2)
Runoff (m3/yr)
0.47
1,116
2,625
1.07
2,571
6,046
10
23
1.04
2,490
5,854
5.36
12,874
30,268
1.05
2,531
5,950
3.30
7,935
18,656
12.29
29,526
69,420
• Pollution removal: 23 metric tons/year ($1.06 million/year)
• Carbon storage: 22,500 metric tons ($3.14 million)
• Carbon sequestration: 992 metric tons/year ($138
thousand/year)
• Building energy savings: $92.9 thousand/year
• Avoided carbon emissions: $23.3 thousand/year
• Structural values: $85.7 million
i-Tree is a
Cooperative
Initiative
among these
Additional features coming soon
• Scenario modeling
• Forecasting (tree
growth projection)
• Mortality
• Flexibility
• Import
• Reduced data needs
• …and more
i-Tree is a
Cooperative
Initiative
among these
i-Tree Hydro: Urban forest hydrology
Natural vs. Disturbed Hydrological Cycle
Precipitation
Evapotranspiration
Interception
Throughfall
Runoff
Infiltration
Infiltration
Pre-developed
i-Tree is a
Cooperative
Initiative
among these
Developed
Green
Infrastructure
i-Tree Hydro model processes
1
2
3
4
5
6
1
Inputs
Spatial Distribution
Canopy Interception
Depression Storage
Surface Runoff
Infiltration
7 Soil Moisture
8 Surface Evaporation
9 Veg Evaporation
10 Evapotranspiration
11 Subsurface Runoff
12 Outputs
9
3
4
5
10
7
2
i-Tree is a
Cooperative
Initiative
among these
8
6
11
12
i-Tree Hydro Watershed Example
Pre-loaded inputs
• Watershed area: 254.8 km2
• USGS stream gauge data/Calibration
Data
• Weather station: CHICAGO/O’HARE
User supplied inputs
• Time period of interest (2011)
• Relative cover
Tree, pervious, impervious, shrub, herbaceous,
water, soil
•
•
•
•
Directly connected impervious area
Leaf area index
DEM
Alternative scenario
i-Tree is a
Cooperative
Initiative
among these
North Branch Chicago River
Watershed example output:
Base vs Alternative, monthly timestep
i-Tree is a
Cooperative
Initiative
among these
Watershed example output:
Base vs Alternative, hourly timestep
i-Tree is a
Cooperative
Initiative
among these
i-Tree Hydro: municipality example
Pre-loaded inputs
• Watershed area: 16.3 km2
• USGS stream gauge data/Calibration
Data
• Weather station: Davison AAF
• Topographic Index
North Branch Chicago River
User supplied inputs
• Time period of interest (2011)
• Relative cover
Tree, pervious, impervious, shrub, herbaceous,
water, soil
• Directly connected impervious area
• Leaf area index
• Alternative scenario
i-Tree is a
Cooperative
Initiative
among these
Fairfax, VA
Municipality example output:
Planning scenarios
Percent change from base scenario flow
30.0%
20.0%
10.0%
development: 5%
canopy loss
reclamation: 5%
canopy gain
targeted: 2.5%
canopy gain
0.0%
-10.0%
-20.0%
-30.0%
Total Flow
i-Tree is a
Cooperative
Initiative
among these
Base Flow
Pervious Flow
Impervious Flow
i-Tree Hydro project scale example:
Green infrastructure (GI) cases
BASE CASE
Parking Lot:
1 Square Block
Minneapolis, MN
i-Tree is a
Cooperative
Initiative
among these
GI 1
GI 2
Parking Lot: with
Permeable
Pavement
Parking Lot: with
Permeable
Pavement + Urban
Tree Plantings
GI Project: Geographical & land cover inputs
Base Case
GI 1 –
Permeable
Pavement
GI 2 – Permeable
Pavement and Urban
Tree Plantings
12,488
12,488
12,488
2.3
2.3
5.1
Pervious under TC
82.3
82.3
78.8
Impervious under TC
17.7
17.7
21.2
Shrub Canopy
0
0
1.1
Herbaceous
10.9
10.9
8.3
Water
0
0
0
Bare Soil
0
38.3
38.1
Impervious
86.7
48.5
47.5
Directly Connected
Impervious Area (%)
31.4
23.4
19.3
• Geographic
Location:
– Parking Lot, 1
Square Block Minneapolis, MN
• Weather Data:
– CRYSTAL 72657594960
• Time Period:
– 01/01/2012 –
9/30/2012
i-Tree is a
Cooperative
Initiative
among these
TOTAL AREA (m²)
Land Cover Area (%)
Tree Canopy (TC)
GI Project Output:
Impervious flow by case
i-Tree is a
Cooperative
Initiative
among these
GI Project Output:
Total suspended solids by case
i-Tree is a
Cooperative
Initiative
among these
Upcoming version will include GI options
i-Tree is a
Cooperative
Initiative
among these
Additional i-Tree resources
www.itreetools.org
Videos
Documentation
Online tools
Newsletter
Support
Examples
Downloads
[email protected] or [email protected]
i-Tree is a
Cooperative
Initiative
among these