Note: This is an update to a previous announcement on the migration to PostGIS.

Our online soil survey, Soil-Web, has now been migrated to a tile-based Ka-Map application. Seamless access to USDA-NCSS soil survey information has never been simpler with a Google-like click and pan-able map interface. Pre-rendered tiles for AZ, CA and NV result in much faster access times, and smooth panning / zooming. A new query interface, based on PostGIS functionality, facillitates soil survey lookup at multiple scales. Users may query by point: by selecting the query tool (looks like an "i") and clicking anywhere on the map. Generalized and detailed soils information at that point are then displayed in the left column of the kap-map application. Clicking an dragging with the query tool selected will search for all soils data which intersects the box. The white box on the figure above simulates the effect of choosing the query tool, and creating a box by clicking and dragging. The results of this simulated query are shown in the left column of the ka-map application. Clicking on the map unit names printed in the query results will take the user to details on that map unit. PLSS coordinates are also listed for each query.

Ka-Map: STATSGO Preview

Ka-Map: SSURGO Preview

Ka-Map: Soils Query

 
Background
Nearly 2 years have elapsed since we put together an online soil survey for AZ, CA, and NV, based entirely on open source tools. GDAL and GRASS were used to pre-process spatial data, MySQL and PostGIS are used to store spatial and attribute data, UMN Mapserver is used to render map images, and PHP-Apache is used to glue it all together. Our first public prototype was advertised just as the USDA-NRCS announced their Web Soil Survey. We often advise parties interested in soils data to use both methods of accessing soil survey information, as each has its respective strong points. Our goal is to provide people a simple means of quickly accessing specific soil properties, with inline definitions to specialized terminology and interpretations. Several methods exists for locating soil data at a given location:

• clickable map (Fig 1)
• street address
• CA zip code
• latitude longitude from NAD83/WGS84 datum
• CA PLSS Township, Range, Section, and Section fractions