Authors: Gregory Yetman*, NASA Global Change Master Directory, Jonh Squires, CIESIN, Columbia University
Topics: Urban Geography, Geographic Information Science and Systems, Water Resources and Hydrology
Keywords: green infrastructure, GIS, impervious, storm water
Session Type: Paper
Start / End Time: 3:20 PM / 5:00 PM
Room: Napoleon D2, Sheraton 3rd Floor
Presentation File: No File Uploaded
Mapping Green Infrastructure and Impervious Surfaces in the City of New York Quantifying contributions of Green Infrastructure (GI) installations to storm water runoff reduction requires mapping at detailed scales in the urban environment. The City of New York has invested significantly in GI for Site-level plans for bioswales, greenstreets, green roofs, and rain gardens to increase infiltration of storm water and reduce discharge to Combined Sewer Outfalls (CSOs). CSO runoff results in pollutant loadings in the waterways around New York City during even moderate rainfall events. Site level data for existing public and private GI installations have been mapped at local levels to gain a citywide view of the change in impervious surfaces. Orthoimagery, building-level models, and planimetric data at the local level have been used to create an integrated database of the natural, engineered GI, and urban built environment. Urban forestry and open space are also included in the database, drawn from the city tree census, planimetric data and imagery. The total impervious and vegetated surfaces of the city, including overlap of vegetation from tree canopies and green roofs with the built environment, are being integrated with statistical models to relate runoff at the sewershed level to estimate contributions to reductions in stormwater runoff resulting in discharge from CSOs. The methods used to map and integrate the data to produce sewershed level data on impervious surface are presented along with an overview of the analysis of runoff data and estimates of stormwater reductions.