Wal-Mart from Space

We introduce an event data set of the location and opening dates for 3,043 Wal-Mart stores as a means for validating land-cover change-related products at medium (28.5 m) to coarse (250 m to 1 km) resolutions throughout the conterminous United States. Strengths of the Wal-Mart validation data set include: construction within most U.S. ecoregions, building footprints greater than a hectare in size, and construction dates that span much of the remote sensing record (1962 to 2004). We built the data set by geo-coding Wal-Mart addresses, establishing opening dates, and geolocating the footprints of 30 stores using online free highresolution (4 m) imagery. Disturbance events were evident at 25 Wal-Marts within a single scene of the Landsat Ecosystem Disturbance Adaptive Processing System (LEDAPS-beta) forest disturbance product. In addition, we found clear disturbance signals within two 16-day vegetation index time series: the 250 m Moderate Resolution Imaging Spectroradiometer normalized difference product (MOD44C) and the 1 km enhanced vegetation index product (MOD13A2).