This dataset was developed as part of the Urban Tree Canopy (UTC) Assessment for Virginia Beach, VA. As such, it represents a "top down" mapping perspective.

High resolution land cover dataset for Virginia Beach, VA. Seven land cover classes were mapped: (1) tree canopy, (2) grass/shrub, (3) bare earth, (4) water, (5) buildings, (6) roads, and (7) other paved surfaces. The minimum mapping unit for the delineation of features was set at 3x3 square feet.

The primary sources used to derive this land cover layer were (1) NAIP 2008 imagery derived from the compressed county mosaic, (2) Normalized digital surface model (nDSM) for Virginia Beach, VA, generated from 2004 light detection and ranging (LiDAR) data representing a 2ft surface. Ancillary data sources used were GIS vector planimetrics layers containing buildings, roads, utility lines, and surface water, provided by the City of Virginia Beach to aid in classification. This land cover dataset is considered current as of November, 2009.

Object-based image analysis techniques (OBIA) were employed to extract land cover information using the best available remotely sensed and vector GIS datasets. OBIA systems work by grouping pixels into meaningful objects based on their spectral and spatial properties, while taking into account boundaries imposed by existing vector datasets. Within the OBIA environment a rule-based expert system was designed to effectively mimic the process of manual image analysis by incorporating the elements of image interpretation (color/tone, texture, pattern, location, size, and shape) into the classification process. A series of morphological procedures were employed to insure that the end product is both accurate and cartographically pleasing.

No accuracy assessment was conducted, but the dataset was subject to a thorough manual quality control. 18194 corrections were made to the classification.

This dataset was developed as part of the Urban Tree Canopy (UTC) Assessment for Virginia Beach, VA. As such, it represents a "top down" mapping perspective.

High resolution land cover dataset for Virginia Beach, VA. Seven land cover classes were mapped: (1) tree canopy, (2) grass/shrub, (3) bare earth, (4) water, (5) buildings, (6) roads, and (7) other paved surfaces. The minimum mapping unit for the delineation of features was set at 3x3 square feet.

The primary sources used to derive this land cover layer were (1) NAIP 2008 imagery derived from the compressed county mosaic, (2) Normalized digital surface model (nDSM) for Virginia Beach, VA, generated from 2004 light detection and ranging (LiDAR) data representing a 2ft surface. Ancillary data sources used were GIS vector planimetrics layers containing buildings, roads, utility lines, and surface water, provided by the City of Virginia Beach to aid in classification. This land cover dataset is considered current as of November, 2009.

Object-based image analysis techniques (OBIA) were employed to extract land cover information using the best available remotely sensed and vector GIS datasets. OBIA systems work by grouping pixels into meaningful objects based on their spectral and spatial properties, while taking into account boundaries imposed by existing vector datasets. Within the OBIA environment a rule-based expert system was designed to effectively mimic the process of manual image analysis by incorporating the elements of image interpretation (color/tone, texture, pattern, location, size, and shape) into the classification process. A series of morphological procedures were employed to insure that the end product is both accurate and cartographically pleasing.

No accuracy assessment was conducted, but the dataset was subject to a thorough manual quality control. 18194 corrections were made to the classification.