Internships

Emeline Blohm ’25

Major

Civil and Environmental Engineering

Project Title

Modeling Tree Rainfall Interception Through Open Data Analysis

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 km² 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.