Challenges in implementing a landslide warning system based on soil moisture sensors in a continental-sized country like Brazil Preliminary results

Brazil has the National Center for Monitoring and Early Warning of Natural Disasters (Cemaden) to monitor natural threats and develop research and technological innovations that contribute to improving the early warning system. Thus, seeking to reduce damage (human and material) from disasters that occur in the country, with the most lethal type being the landslides. In 2019, the center began installing a network of stations to measure soil moisture in several high-risk cities. The equipment, called PCD (Data Collection Platform), corresponds to a rainfall station coupled to a probe with capacitance sensors installed in wells that measure (at 10-minute intervals) the volumetric soil moisture every 0.5m up to 3m of depth. With Cemaden receiving now the data from the first 21 cities in real-time. However, there are many challenges in implementing such a system in a country as large and diverse as Brazil. PCDs were installed from poor communities (favelas) on the coast in the equatorial region, to small middle-class rural properties in mountainous areas in the temperate zone of southern Brazil. Always dealing with challenges in installation and especially in station maintenance. However, although real-time monitoring is already useful in the Situation Room (which works 24/7), the center is looking for new ways to analyze the data and use it to create more advanced alert systems. Starting with the interpretation improvement of such diverse data, from places with different soil structures and rainfall regimes, in addition to completely different land cover characteristics. We are also aiming to obtain environmental thresholds and landslide risk scenarios. For the near future, the use of the data series is planned for the development of new tools for monitoring and forecasting mass movements. In this work, we present the preliminary results obtained with the historical series of some of the critical cities. We show the behavior of soil layers in different cities, the difficulties in installing and maintaining the equipment, in addition to the first products to be used in the Situation Room. With an example of a landslide in a location near a PCD that occurred shortly after its installation.