A Fully Automated Approach to Classifying Urban Land Use and Cover from LiDAR, Multi-spectral Imagery, and Ancillary Data Jason Parent Qian Lei University of Connecticut Land cover and land use Land cover: the physical material on the earth’s surface (e.g. water, grass, asphalt, etc.) Land use: the use of the land by humans (e.g. reservoir, agriculture, parking lot, etc.) Fundamental to landscape analyses and urban planning. 2 Opportunities and challenges for high resolution data Increasing availability of airborne light detection and ranging (LiDAR) and aerial imagery offers opportunities to study landscapes in great detail. Technically challenging to process… require lots of hard drive space. datasets must be divided into small subsets for processing. conventional algorithms not well suited to processing large numbers of subsets Study objectives and justification Develop fully automated algorithm to classify high resolution (1-meter) land cover / land use which is applicable over large areas. Specifically, we developed python scripts with ArcGIS to… 4 no previously presented algorithm has been feasible to apply over large areas. classify 1-meter land cover from LiDAR and multispectral data. infer land use from object geometry and spatial context of land cover features. Study area Located in eastern Connecticut in the northeastern U.S. Semi-random stratified sample of 30 1x1 km tiles. 5 Stratified by % impervious cover (according to Connecticut’s Changing Landscape land cover data). 4800 km2 % impervious 0 - 33 33 - 66 66 – 100 Data LiDAR 2010 leaf-off fall acquisition Small footprint (44 cm) Near-infrared (1064 nm) > 1.5 pts/m2 6 Aerial orthophotos 2012 leaf-off spring acquisition Blue, green, red, and NIR 0.3 meter resolution Land cover classification rules Land cover Building Low impervious cover (low IC) Deciduous forest Coniferous forest Medium vegetation Water Riparian wetlands Low vegetation 7 Primary characteristics Height > 2.5m; no ground returns Low NDVI; no returns 2 to 4.5 meters above ground Height > 3m; high NDVI Pixel- and object-based Height > 3m; very high NDVI rules using structural and Height 0.5 to 3m; high NDVI spectral properties No returns Low reflectance in all bands; adjacent to water High return intensity Land cover classification example Land Cover deciduous trees deciduous evergreen trees coniferous medium med.vegetation veg. grass vegetation low/ low veg. water water wetland wetland building building road low/ parking IC lot / barr 8 Land cover class accuracies User accuracy: probability that a cell label is correct. Producer accuracy: probability that a cell is correctly labelled. Class Water Building Low vegetation Wetland Low impervious Med. vegetation Coniferous trees Deciduous trees User acc. (%) Prod. acc. (%) 96 99 91 26 93 61 90 95 85 97 94 35 91 60 76 96 n = 3200 93% overall Kappa = 0.90 Land use classification rules Building use Primary characteristic Non-Residential Large parking area; flat roof; large Objectand parcelbuilding size based rules Large parking area;using narrowobject building width; similar building shapes shape/size and parcel Small parking area; peak roof; landbuilding cover small sizecomposition Multi-family residential Single family residential 10 Parcel cadastral information not used because of limited availability. Land use preliminary results Land Cover deciduous trees deciduous evergreen trees coniferous medium med.vegetation veg. grass vegetation low/ low veg. water water wetland wetland building building Land Use road low/ parking IC lot / ba 18TBG5110_bldg ParcelCls Multi-Family Residen multi-family Non-Residential non-resid. Single-Family Reside single-family Land use classification assessment Qualitative assessment notes… 12 small commercial buildings misclassified as single family due to similar structural characteristics problems caused by mismatch between land cover and parcel data 12 Conclusions and future work Land cover classification: Land use classification: 13 Use of airborne LiDAR and multi-spectral data proved highly effective in classification of high resolution land cover. Developed fully automated algorithm that performs well over large area. Use of building shape and context is promising Future work will develop rules for classification of… roads vs. parking lots urban vs. non-urban forest agriculture vs. turf Questions? A Fully Automated Approach to Classifying Urban Land Use and Cover from LiDAR, Multi-spectral Imagery, and Ancillary Data Jason Parent Qian Lei University of Connecticut