Cellular telephone telemetry offers an economical and convenient means of conducting remote, near-real-time landslide monitoring, and for acquiring data to improve understanding of landslide processes. Cellular coverage is usually available in urban areas and along major transportation corridors, areas where landslides often pose the greatest risk to people and infrastructure. Cell-phone based monitoring systems offer the advantage of data acquisition and communication with remote sites via computer dial-up from any location where telephone service is available. Two-way communication also allows remote modification of data recording parameters, alert threshold values, and communication parameters as conditions change. Automatic dial-out on detection of an alert condition provides immediate notification to pre-defined pager numbers, and monthly service and airtime costs are low, making long-term monitoring and remote acquisition of data recorded on the order of hours or minutes quite cost effective.

Researchers in the U.S. Geological Survey, Central Region Landslide Hazards Group, have been deploying cell-phone based monitoring systems as part of landslide research and hazards response activities over the past several years. Examples from our experience with cell phone based monitoring systems include: 1) remote monitoring that produced a nearly continuous record of infiltration and soil-moisture conditions for a three-year period following a major wildfire in New Mexico, 2) continuous monitoring and acquisition of movement data on the unstable headscarp of a landslide in California that provided local officials with current movement status and produced a three-year record of headscarp response to seasonal precipitation patterns, 3) rapid response monitoring of part of a major landslide above Interstate 70 in western Colorado that identified previously unknown movement that could impact future landslide activity, and 4) remote monitoring that is aiding Bureau of Land Management officials to track movement of a large landslide in southern Idaho without the necessity of frequent site visits.

Our experience indicates that remote monitoring is generally reliable and can be economically viable, but unfortunately remains largely underutilized in landslide hazards reduction practice.