Geoka, a private German geospatial research organization, has developed a new kind of map that can detect underground conditions that lead to landslides such as the one that occurred in Laguna Beach, Calif., and destroyed about a dozen multimillion dollar homes. The new hazard mapping technology, known as a Ladwein Map, named after its developer and Geoka Chief Scientist, Richard Ladwein, shows the exact location of underground conditions that precipitate such disasters.
Using traditional methods of land surveying, an engineer would be able to tell a builder or a homeowner whether or not an area such as a bluff was safe to build on, but it wasn’t very exact. A survey by traditional means would show that the whole area was unsound to build on; or, as was the case with a recent landside in La Conchita, surveyors failed to predict a landslide using traditional means. The error lies with the method of detect weak spots in a plot of land whereby an engineer will drill holes in an area being examined, analyze the material and often find erroneously that the earth is stronger in these areas than elsewhere in the slope, leading to the false impression of security, Geoka said in a statement on their Web site following the release of an analysis of the La Conchita landslide.
With the Ladwein map, engineers doing a geological survey would have determined the exact plots of land with weak spots caused by mud, sink holes and soil saturation, allowing building to occur on strong plots of land while leaving the weak ones alone. In a residential application, the map could help city officials give residents a better understanding of the hazards of their land while allowing for its safer utilization.
Ludwein maps have also been used in Trujillo, Venezuela and Lucerne, Switzerland.