Abstract-Monitoring and early warning systems, although being capable of continuously collecting field data related to landslide processes, are usually unable to autonomously detect and analyze signs of landslides in real time. This paper presents the design and experimental implementation of an autonomous landslide monitoring system. Besides reliably issuing early warnings in case of detected slope anomalies, the monitoring system is primarily designed to support human individuals in assessing the risk of landslide and to improve the understanding of the slope behavior, which may help to reduce economic losses and fatalities caused by landslides. Specifically, intelligent wireless sensor nodes are distributed in the observed slope to autonomously collect, analyze and communicate relevant environmental parameters in real time. Supporting remote analyses of the collected field data, a web application, which is installed on a computer connected to the on-site sensor nodes, enables an automated dissemination of slope parameters through the Internet. Last but not least, geospatial information stemming from external sources is integrated into the monitoring system to provide a comprehensive overview of landslide-related slope conditions. Index Terms-Monitoring of slope movements, wireless sensor networks, early warning systems, artificial intelligence, smart sensors, Internet computing.
I. INTRODUCTIONThe world population, which currently numbers more than 7 billion people [1], is growing continuously, and it is expected to reach 10 billion people in the year 2100 [2]. As a direct consequence of the population growth, also the density of population increases rapidly, and therefore unstable, hazardous areas and steep terrains with high risks of natural hazards such as volcanic eruptions, floods or landslides are being developed for settlement [3]. As another direct consequence of the population growth, human activities increasingly trigger natural hazards due to changes in the environmental conditions. For example, landslides are frequently initiated by human-induced factors, such as disturbed or changed drainage patterns, destabilized slopes, or removed vegetation [4]. Landslides, according to the United States Geological Survey (USGS) are defined as "downslope movement of soil, rock and organic materials under the effects of gravity" [4]. Generally, landslides occur in different terrains independently from climate conditions, and they are among the most common but also among the most dangerous natural hazards, because civil infrastructure cannot withstand the forces generated by moving masses of soil, rock, or organic material. Having severe impact both on civil infrastructure and on the natural environment, landslides cause losses and damages of several billion US$ every year as well as numerous fatalities and injuries [4]. As reported by Petley [5], who has investigated fatal landslides between 2004 and 2010, during the 7-year observation period 2,620 landslides have been recorded, which have caused more than 30,0...