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Land-cover mapping of the central Arizona region based on 2015 National Agriculture Imagery Program (NAIP) imagery

Publication date: 2020-09-25

Author(s):

  • Yujia Zhang, Arizona State University
  • Billie Turner II, Arizona State University

Abstract:

Detailed land-cover mapping is essential for a range of research issues addressed by sustainability science, especially for questions posed of urban areas, such as those of the Central Arizona-Phoenix Long-Term Ecological Research (CAP LTER) program. This project provides a 1-meter land-cover mapping of the CAP LTER study area (greater Phoenix metropolitan area and surrounding Sonoran desert). The mapping is generated primarily using 2015 National Agriculture Imagery Program (NAIP) four-band data, with auxiliary GIS data used to improve accuracy. Auxiliary data include the 2015 cadastral parcel data, the 2014 USGS LiDAR data (1-meter), the 2014 Microsoft/OpenStreetMap Building Footprint data, the 2015 Street TIGER/Line, and a previous (2010) NAIP-based land-cover map of the study area (https://portal.edirepository.org/nis/mapbrowse?scope=knb-lter-cap&identifier=623). Among auxiliary data, building footprints and LiDAR data significantly improved the boundary detection of above-ground objects. Post-classification, manual editing was applied to minimize classification errors. As a result, the land-cover map achieves an overall accuracy of 94 per cent. The map contains eight land cover classes, including: (1) building, (2) asphalt, (3) bare soil and concrete, (4) tree and shrub, (5) grass, (6) water, (7) active cropland, and (8) fallow. When compared to the aforementioned, previous (2010) NAIP-based land-cover map for the study area, buildings and tree canopies are classified more accurately in this 2015 land-cover map.

Keywords:


Temporal Coverage:

2015-05-29 to 2015-06-01

Geographic Coverage:

Geographic Description: CAP LTER study area: greater Phoenix, Arizona (USA) metropolitan area and surrounding Sonoran desert region
Bounding Coordinates:
Longitude:-112.8256 to -111.5581
Latitude:33.8871 to 33.1756

Contact:

Information Manager, Central Arizona–Phoenix LTER, 
Arizona State University,Global Institute of Sustainability,Tempe
 caplter.data@asu.edu

Methods used in producing this dataset: Show


Data Files (6) :

Tabular: 685_accuracy_assessment_3450f3e8c9db5f54201e390e06839630.csv

Description: Accuracy assessment of classification. This data table details classification accuracies for each land-use, land-cover class. Overall accuracy of the classification (sum of correctly_classified_count / sum of reference_count (or classified_count)) was 94%. These data are included with the dataset metadata, and the contents of this file mirrors that information

Column Description Type Units
class_name land-cover category name
string
Enumeration:
  • Active Cropland: This class is cropland covered by green vegetation.
  • Asphalt: This is the dark color impervious surface. This class mainly contains road and parking lots.
  • Bare Soil & Concrete: This class includes bare soil, sand, gravel, and rock in urban and desert environments. It also contains light color impervious surface such as concrete.
  • Building: This class contains all types of buildings in residential, commercial, and industrial areas.
  • Fallow: This class is cropland without green vegetation.
  • Grass: This class is mainly turf grass. It may also contain shrubs that are lower than 1.5-meter. The tree versus grass classification (1.5-meter height threshold) depends on LiDAR data availability. However, the 2014 USGS Lidar data only covered 21% of the CAP study area. Please see 685_LiDAR_extent.kml for more details.
  • Tree & Shrub: This class contains trees and shrubs that are higher than 1.5-meter. The tree versus grass classification (1.5-meter height threshold) depends on LiDAR data availability. However, the 2014 USGS Lidar data only covered 21% of the CAP study area. Please see 685_LiDAR_extent.kml for more details.
  • Water: This class includes different types of water bodies, such as lake, pond, canal, and swimming pools.
correctly_classified_count count of correctly classified pixels
float number
reference_count count of reference pixels
float number
classified_count count of classified pixels
float number
producer_accuracy correctly_classified_count / reference_count
float dimensionless
user_accuracy correctly_classified_count / classified_count
float dimensionless

Tabular: 685_land_cover_classes_37ee358ab2c5f550bebcc36751f67fe4.csv

Description: companion file to the dataset .tif file that details the corresponding LULC (land use, land cover) type of each raster value; these data are included with the .tif metadata and the contents of this file mirrors that information

Column Description Type Units
class_id land-cover raster value
string
class_name land-cover category name
string
description land-cover category description
string

Spatial Vector: 685_LiDAR_extent.kml

Description: Areal coverage of 2014 LiDAR data available to support the 2015 land-cover classification. The 2014 USGS Lidar data only covered 21% of the CAP LTER study area. Within the area covered by LiDAR, tree and grass achieved higher accuracy (> 95%); outside the area, the tree versus grass classification was less accurate due to the lack of surface-height information. This LiDAR extent was modified based on the NAIP image tile boundaries. The full 2014 USGS Lidar extent can be accessed from https://lib.asu.edu/Geo/news/New-Web-Map-Accessing-Phoenix-LiDAR-Data
Temporal Coverage: 2014-09-30 to 2014-10-05
Horizontal Coordinate System:GCS_WGS_1984
Geometry Type: Polygon

Column Description Type Units
Tile_Name tile identifier that references corresponding LiDAR data for that location
string
Name tile identifier that references corresponding LiDAR data for that location
string

Raster: 685_land_cover_1m_2015_a8db4e50b4c88ceaf4e11cb73616f316.tif

Description: Fine-resolution (1-meter) land-cover mapping of the CAP LTER study area (greater Phoenix metropolitan area and surrounding Sonoran desert). The mapping is generated primarily using 2015 National Agriculture Imagery Program (NAIP) four-band data, with auxiliary GIS data used to improve accuracy. Auxiliary data include the 2015 cadastral parcel data, the 2014 USGS LiDAR data (1-meter), the 2014 Microsoft/OpenStreetMap Building Footprint data, the 2015 Street TIGER/Line, and a previous (2010) NAIP-based land-cover map of the study area.
Temporal Coverage: 2015-05-29 to 2015-06-01
Horizontal Coordinate System:NAD_1983_UTM_Zone_12N
Rows:77561
Columns:116828

Column Description Type Units
raster_value categorical value indicating LULC (land use, land cover) type
string
Enumeration:
  • 1: Building: This class contains all types of buildings in residential, commercial, and industrial areas.
  • 2: Asphalt: This is the dark color impervious surface. This class mainly contains road and parking lots.
  • 3: Bare Soil & Concrete: This class includes bare soil, sand, gravel, and rock in urban and desert environments. It also contains light color impervious surface such as concrete.
  • 4: Tree & Shrub: This class contains trees and shrubs that are higher than 1.5-meter.
  • 5: Grass: This class is mainly turf grass. It may also contain shrubs that are lower than 1.5-meter.
  • 6: Water: This class includes different types of water bodies, such as lake, pond, canal, and swimming pools.
  • 7: Active Cropland: This class is cropland covered by green vegetation.
  • 8: Fallow: This class is cropland without green vegetation.

File: 685_land_cover_1m_2015_01d2be822e676e572bae5829b3124096.clr

Description: companion file to the dataset .tif file that details a color profile for the .tif raster values


File: 685_land_cover_1m_2015_30df46aeafa3405285513e1435f40973.dbf

Description: companion file to the dataset .tif file that details the corresponding LULC (land use, land cover) type of each raster value; these data are included with the .tif metadata and the contents of this file mirrors that information


Download EML Metadata for this data package