Investigating Earth Changes over Space and Time with the Landsat Lens
Many web mapping applications provide an excellent teaching and research resource, because they are easy to use, quick to display, rich with data, and powerful. One of the newest and most useful web mapping applications is the Landsat Lens. The Landsat Lens is so named because it provides a "lens" of a series of Landsat images by year, by theme, and by region, selectable by the user. In other words, it is the perfect tool to investigate changes over space and time. Hence, it can be used in courses in geography, environmental science, hydrology, civil engineering, biology, GIS, and remote sensing, just to name a few.
Upon opening, the app shows a lens (Landsat image) dated 2017 located near the Palm Jebel Ali in Dubai. A set of preset locations are available from the Bookmarks dropdown menu, or you can pan or zoom to any area of interest. For one of the preset locations, or for your own area of interest, you may want to view changes over time. To do so, use the Windows dropdown menu to add a window showing 2002, 2005, 2010, 2015 or 2017 imagery. By swiping lenses over the basemap and one another you can easily see changes from natural or human causes, in vegetation cover, agricultural expansion or contraction, urbanization, coastline erosion or modification, river dams or meanders, volcanic activity, or from other causes. Use the last option in the dropdown menu to remove all lenses from the map. You can also select themes such as Agriculture, Color Infrared, Natural Color, Moisture Index, or Vegetation Index, each of which focuses on specific bands in the electromagnetic spectrum to highlight these themes. You can change the scale and even change the size of the "lenses" themselves.
Landsat Lens web mapping application for an area southeast of Las Vegas, Nevada, USA.
For more information, see the blog post of my colleague who developed this amazing tool, his handy help file, and my video guiding you through some of this app's features. Give Landsat Lens a try and I look forward to your comments below.