<p>Urban and small catchments flooding is a common type of natural hazard caused by intense rainfall, which may cause inundation to roads, buildings, and infrastructure, interrupting transportation, power lines and, other critical urban infrastructure systems, damaging properties and threatening people’s lives. The expansion of urban areas and infrastructure over the last 50 years has led to a marked increase in flood risk.</p> <p>The coastal and hilly areas of Central Italy have been largely affected by heavy rainfall and flood/flash-flood events in recent times. The Apennine hilly piedmont and the coastal hills of Abruzzo have been affected by moderate to heavy events (rainfall >35 mm/h and 100-220 mm/d), which caused damages to minor and major urban areas. In this study, the Feltrino Stream area and the Lanciano town were investigated for the realization of a local early warning system for heavy rainfall events and flooding. The project is funded by the Abruzzo Region within the frame of a regional Project named “Communicate to protect” and developed in collaboration with the Lanciano Municipality and with the Regional Civil Protection office.</p> <p>The Feltrino Stream basin is located in the hilly area of southeastern Abruzzo, in the eastern piedmont of the Maiella massif (Central Apennines). The basin ranges from about 400 m a.s.l. to sea level, with an overall morphology characterized by a mesa and plateau relief and SW-NE elongated valleys. The Lanciano Town is developed on a mesa relief carved by minor valleys, largely modified and filled by anthropic activities.</p> <p>In this work, the Feltrino Stream was investigated through a drainage basin scale geomorphological analysis incorporating (i) the morphometry of orography and hydrography, (ii) temperature and rainfall data analysis, (iii) acquisition of available geological, geomorphological, and hazard data, (iv) detail urban hydrography analysis and geomorphological field mapping, for the definition of a geodatabase of the geo-hydrological critical areas. The analysis allowed defining the arrangement of a rainfall, hydrometry and flood monitoring system integrating at local scale the existing regional monitoring network. The integration of the monitoring system and the critical areas in a web cloud digital system allowed to plan and realize an early warning system, based on the use of a digital app for smartphone. The warning system is being calibrated for the effectiveness during heavy rainfall events. After calibration, the system will support the local civil protection activities of the Lanciano Municipality. Moreover, under the supervision of the civil protection responsible, it is expected to be implemented as an automatic system for smartphone-based early warning of people exploiting the inbuilt geolocalization features of the recent smartphone.</p>

Urban and small catchment landslides and floods are common types of hazards caused by intense rainfall. The detailed geomorphological mapping and analysis of the superficial hydrographic network are fundamental tools to assess the geo-hydrologically critical areas. In this study, the Feltrino Stream and Lanciano area (Adriatic coastal-hills) were investigated through a basinscale and urban-scale geomorphological analysiswhich incorporated temperature-rainfall and morphometric analyses, and the acquisition of geomorphological and hazard data, integrated with geomorphological fieldwork and mapping. The creation of a geodatabase and the data overlay led to assess the landslide-flood critical areas through geomorphology-based matrices. This study aimed to define the distribution of landslide-flood historical/recent events and related critical areas for the realization of an urban EWS, composed of a network of nine gauges, integrating the existing regional monitoring network. It defined a local alert system for landslide-flood and could support real-time communication for civil protection purposes.

This work is based on a drainage basin-scale geomorphological investigation combined with flood modeling. It is focused on the assessment of flood critical areas for the implementation of a geomorphology-based urban Early Warning System (EWS) in the urban area of Lanciano and the Feltrino Stream basin (a minor coastal basin of the Abruzzo hills, Central Italy). This area was investigated by combining: pre-existing geological, geomorphological, and hazard data and new detailed field surveys and mapping of geomorphological and hydrographical features (superficial and buried natural and urban stream network). The study was integrated with 2D flood numerical modeling for verifying the expected flooded areas and calibrating the critical areas. All the collected data were integrated into a geodatabase, and an expert-based approach through a geomorphology-based matrix allowed us to define the main categories of flood critical areas. The assessment of the critical areas supported the emplacement of a network of rainfall, temperature, and flood gauges. The geodatabase, the derived critical areas, and the gauge network contributed to set up an urban EWS, integrated with the regional forecast-based warning system. This system provides combined forecast-based, rainfall threshold-based, and flood monitoring-based alerts for floods. It incorporates communication tools for civil protection management. Finally, the EWS provides a tool for civil protection purposes and for the management of flood critical areas and the mitigation of the related risks by local authorities and will be integrated with sensors related to other hazards (i.e., landslides, wind, etc.).