Low-lying coastal zones are highly subject to coastal hazards as a result of sea-level rise enhanced by natural or anthropogenic land subsidence. A combined analysis using sea-level data and remote sensing techniques allows the estimation of the current rates of land subsidence and shoreline retreat, supporting the development of quantified relative sea-level projections and flood maps, which are appropriate for specific areas. This study focuses on the coastal plain of Tavoliere delle Puglie (Apulia, Southern Italy), facing the Adriatic Sea. In this area, land subsidence is mainly caused by long-term tectonic movements and sediment compaction driven by high anthropogenic pressure, such as groundwater exploitation and constructions of buildings. To assess the expected effects of relative sea-level rise for the next decades, we considered the following multidisciplinary source data: (i) sea-level-rise projections for different climatic scenarios, as reported in the Sixth Assessment Report of the Intergovernmental Panel on Climate Change, (ii) coastal topography from airborne and terrestrial LiDAR data, (iii) Vertical Land Movement (VLM) from the analysis of InSAR and GNSS data, and (iv) shoreline changes obtained from the analysis of orthophotos, historic maps, and satellite images. To assess the expected evolution of the coastal belt, the topographic data were corrected for VLM values, assuming that the rates of land subsidence will remain constant up to 2150. The sea-level-rise projections and expected flooded areas were estimated for the Shared Socioeconomic Pathways SSP1-2.6 and SSP5-8.5, corresponding to low and high greenhouse-gas concentrations, respectively. From our analysis, we estimate that in 2050, 2100, and 2150, up to 50.5 km², 118.7 km² and 147.7 km² of the coast could be submerged, respectively, while beaches could retreat at rates of up to 5.8 m/yr. In this area, sea-level rise will be accelerated by natural and anthropogenic land subsidence at rates of up to −7.5 ± 1.7 mm/yr. Local infrastructure and residential areas are thus highly exposed to an increasing risk of severe inundation by storm surges and sea-level rise in the next decades.

Digital elevation models (DEMs) represent a fundamental resource in geomorphological analysis. The increasing availability of open‐access DEMs over wide areas is advantageous, but requires an evaluation of DEM quality and errors. This work applies a hierarchical assessment of global, continental and national DEMs in Italy in order to explore the differences and analyze the vertical accuracy, spatial error distribution and agreement of morphometric measurements. The selected DEMs are compared with local reference data as a ground points dataset, extracted from the national geodetic network, and regional DEMs at high spatial resolution, through both a qualitative and a quantitative approach. The results identify limits and potentialities of the selected DEMs, showing accuracy and errors in height representation, also affected by the topographic characteristics of the surface, such as steep slope in mountain zones and some defects in hydromorphological derivatives that could condition the geomorphological applications.

We analyze the variation in groundwater budget by modeling an aquifer in a semi-arid region in southern Italy, using different good pumping scenarios. This aquifer is overexploited due to the agricultural vocation of the area. We propose an integrated method to assess the distribution of hydrogeological parameters and the recharge rates. The hydrogeological parametrization is performed through a hydrostratigraphic approach using the geostatistical tool. Recharge rates are computed through a soil water balance application, using different monitoring stations over the area for the whole period of interest. Integrating the results of this analysis with pumping scenarios based on the water irrigation requirement of the main crops in the area, different water budgets are estimated. The results show how different pumping scenarios affect the availability of water resources and thus underline the importance of management. This integrated hydrogeological model can be applied to other areas with similar hydrogeological characteristics, and it can be considered a valuable tool for evaluating sustainable groundwater management strategies, considering land use practices and socio-economic factors.

This study focuses on the geo-hydrological characterization of the coastal zone of Tavoliere delle Puglie (Apulia region, Italy), one of the widest coastal plains in southern Italy. Nowadays, the area, mostly devoted to agricultural purposes, is subjected to several natural and anthropogenic stresses, such as sea-level rise and consequent shoreline modifications, groundwater pumping from shallow and deep aquifers, and land subsidence, strongly enhanced by human activity. Recent investigations have been conducted to assess the impact of relative sea level rise along coastal sectors over the next few decades by considering multidisciplinary data. These include IPCC sea-level rise projections for different climate scenarios (SSP1-2.6 and SSP5-8.5); coastal topography from airborne and terrestrial LiDAR data, vertical land movement rates obtained from the analysis of InSAR and GNSS data, and shoreline displacement derived from the analysis of multiple sources. According to the results of such analyses, under the worst-case scenario (SSP5-8.5), the local sea-level rise will reach values of 0.39 ± 0.12 m, 1.23 ± 0.31 m, 2.07 ± 0.56 m with a land surface of 50.5 km2, 118.7 km2, and 147.7 km2 potentially submerged in 2050, 2100, and 2150, respectively. Regarding the hydrogeological characterization of local coastal aquifers, recent studies have highlighted that groundwater overexploitation has led to a significant decline in piezometric levels, reducing the natural hydraulic barrier of groundwater that prevents the intrusion of saline water from the sea. By using a combination of models, i.e. independent soil water balance and a groundwater flow model, the hydrogeological balance and related groundwater budget have been assessed for three different pumping scenarios: FullIWR (full irrigation water requirement), IWR under CDI (irrigation water requirement under controlled deficit irrigation) and ActIWR (current irrigation water demand). About 300 borehole stratigraphies allowed to build the groundwater conceptual model, while the distribution of the hydrogeological parameters of the aquifer has been estimated by means of a variety of geostatistical tools. The modelling results suggest that both groundwater discharge and storage decrease in time due to i) reduction of effective infiltration, ii) increase in water demand for agricultural practices, iii) changes in rain regime, and iv) increase in evapotranspiration rate.The ingression of marine water compromises groundwater quality, reducing the underground freshwater resources, making it unsuitable for human and agricultural purposes and posing a risk to regional water security. The vulnerability due to this phenomenon is exacerbated by Relative Sea-Level Rise (RSLR), which further increases the pressure gradient driving saltwater into coastal aquifers, moving inland the coastline. Therefore, further investigations will focus on modeling the salinization of the aquifers due to the seawater intrusion as a consequence of RSLR. This will provide a comprehensive understanding of groundwater flow dynamics for supporting the integrated management of the coastal areas in response to ongoing climate change and defining tailored land-use practices for the sustainable exploitation of groundwater resources.