The U.S. Army Corps of Engineers (USACE) is responsible for thousands of miles of levees in the United States. Over time the agency has developed a very specific way of evaluating levee systems and relationships between their constituent parts. This approach has served USACE well, at least until having to coordinate our internal data structures with additional data managed by other agencies or programs who potentially treat levees in very different ways. Solving this requirement led to a new approach being developed inside the USACE National Levee Database program referred to as Reaches. Based on linear referencing, the Reaches approach combines interactive creation of linear event themes, a graphical linear reference data editor, and user driven symbolization of the data within a single comprehensive web interface. Using a combination of OpenLayers, GeoExt on the client side and Oracle SDO, MapServer and GeoTools on the server, it is optimized both for speed and flexibility, putting the power of the linear referencing approach into the hands of a range of technical and non-technical users. This presentation presents an architectural overview of the system and how FOSS applications were leveraged during development of Reaches.
The ability to manage data with a new level of flexibility and interactivity is supported in some cases by our new unmanned aerial vehicle (UAV) imagery pipeline. Flying imagery from altitudes only in the hundreds of feet give us images with resolution down to inches. By stitching these images into geotiff mosaic composites then processing into individual MBTiles databases using TileMill, we get a new level of perspective on construction projects and any other ground conditions, allowing for monitoring change over time at a convenience and price our agency has not previously had available. The full capability of this imagery is brought to light by our custom tile services that are generated down to zoom level 24. This presentation will show how by pairing the new imagery capabilities with the Reaches tools for collecting and storing data, our non-technical users now have access to tools and data normally reserved for the GIS/RS team.