A half dozen states are developing landslide inventories with some of them also producing state-wide landslide susceptibility maps. At the GSA annual meeting in Houston, there was a poster session dedicated to these as prototypes of a national landslide inventory. A number of us gathered around the posters in the morning and went through them with the authors. The USGS is linking to these via their landslide Web page.
The pilot project partners have come up with a preliminary set of criteria for characterizing landslides in the inventories that all participants will want to use at a minimum. Some states are adding much more. North Carolina for example, has 122 characteristics on their data entry form, although only about 10% of their landslides have close to this extensive documentation.
A national landslide inventory and assessment program has been a goal of the state geological surveys for the past decade, but it has not gotten much traction at the federal level. The GSA session is good news that there is growing interest in revitalizing this effort.
Arizona has had its share of serious landslide-related ground failure events in the past couple of years - Sabino Canyon and Coronado National Memorial debris flows in 2006, additional debris flows in the Catalina Mountain foothills, the Easter 2008 landslide on State Route 87 between Phoenix and Payson, and new earth fissures opening up during each monsoon.
Landslides are a serious problem in Arizona and the new work in other states will be valuable tools for us to use.