Urban Ecological Land – Cover Mapping for New York City
By Spatial Informatics Group
By Spatial Informatics Group
An urban ecological land-cover map containing 37 unique classes was created for New York City using object-based imagery analysis (OBIA) techniques in conjunction with multispectral orthoimagery, Light Detection and Ranging (LIDAR) data, and thematic Geographic Information System (GIS) layers. Based on a classification scheme adapted from the United States National Vegetation Classification (NVC), the new map included a mix of ecological and anthropogenic features mapped across four hierarchical levels of detail: 1) basic land cover; 2) land-cover sub-classes; 3) NVC Group; and 4) NVC Association. All ecologically-relevant classes were mapped to the NVC Group level, and a subset of 9 classes were mapped to the NVC Association level. An accuracy assessment conducted on the Level 2 map indicated an overall accuracy of 92%, a high classification rate attributable in part to the efficient mapping of widely-distributed upland forest classes. However, forested wetlands and other uncommon wetland features were mapped with much lower accuracy, suffering particularly from high rates of omission. Insufficient reference data were available to conduct a quantitative accuracy assessment for the Level 3 and Level 4 NVC classes, but the quality of these classes likely varied by data input (i.e., high for classes based on expert opinion, lower for classes based on spectral criteria). The current map will serve as baseline documentation for monitoring and protection of NYC’s most important ecological features, and subsequent versions could be materially improved by advances in wetlands mapping and additional field-based expert opinion.
Read Report(this link opens in new window)This report summarizes the main threats to one type of urban natural area–forests–and the strategies cities use to minimize or negate these threats. Overall, this report shows that cities use various tactics such as ordinances, zoning, land acquisitions, and federal protections to preserve natural areas. The most successful approaches feature o...
More than half of the world’s population lives in urban areas. Sustaining healthy urban forests is increasingly relevant to this population given the wide range of economic, ecological, and social benefits that urban forests provide. Yet forests in cities grow in sites that are fragmented, with frequent disturbance, altered soils, and complex lan...
The Natural Areas Conservancy developed and implemented a study to gather data on fiscal year 2017–fiscal year 2020 funding and resources allocated for forested natural areas care in New York City. The NAC developed a questionnaire for NYC Parks Division of Forestry, Horticulture, and Natural Resources (FHNR, now NYC Parks Environment & Plann...