Environmental Internship Program - 2023 Booklet

Emeline Blohm ’25
CIVIL AND ENVIRONMENTAL ENGINEERING
PROJECT TITLE
Modeling Tree Rainfall
Interception Through Open
Data Analysis
ORGANIZATION(S)
Urban Modeling Group,
Tandon School of
Engineering, New York
University (NYU)
LOCATION(S)
Brooklyn, New York
MENTOR(S)
Debra Laefer,
Professor of Urban
Informatics, Tandon
School of Engineering,
NYU
I developed an original methodology to estimate
the rainfall interception and storage capacity
of 98,700 trees in Brooklyn, New York. Urban
flood models often neglect tree canopy as a form
of green infrastructure mitigation, but trees
mitigate pluvial flooding by intercepting and
storing rainfall. The quantity of rain mitigated
by an individual tree depends on characteristics
such as species, diameter, height and canopy
area. For large areas with diverse tree types,
remote sensing datasets can be used to estimate
these features. I gathered tree features for
20.25 km 2 of Brooklyn from two open datasets.
I processed these datasets and calculated the
bark and leaf storage per block based on values
aggregated from peer-reviewed literature. In the
application QGIS, I visualized the distribution
of tree canopy and bark and leaf rainfall storage
per block and total storage per square meter of
canopy. I used the storage values in an existing
model and found that for the study area, the total
tree storage is over 1.7 million liters of rain. I
also found that the bark surface intercepts more
water than the leaf surface (77.5% vs. 22.5%).
These results can be integrated into flood models
to evaluate the impact of tree cover on pluvial
flooding.
ENVIRONMENT AND SOCIETY
AND URBAN SUSTAINABILITY
37