The International Soil Moisture Network:Serving Earth system science for over a decade

In 2009, the International Soil Moisture Network (ISMN) was initiated as a community effort, funded by the European Space Agency, to serve as a centralised data hosting facility for globally available in situ soil moisture measurements (Dorigo et al., 2011b, a). The ISMN brings together in situ soil moisture measurements collected and freely shared by a multitude of organisations, harmonises them in terms of units and sampling rates, applies advanced quality control, and stores them in a database. Users can freely retrieve the data from this database through an online web portal (https://ismn.earth/en/, last access: 28 October 2021). Meanwhile, the ISMN has evolved into the primary in situ soil moisture reference database worldwide, as evidenced by more than 3000 active users and over 1000 scientific publications referencing the data sets provided by the network. As of July 2021, the ISMN now contains the data of 71 networks and 2842 stations located all over the globe, with a time period spanning from 1952 to the present. The number of networks and stations covered by the ISMN is still growing, and approximately 70 % of the data sets contained in the database continue to be updated on a regular or irregular basis. The main scope of this paper is to inform readers about the evolution of the ISMN over the past decade, including a description of network and data set updates and quality control procedures. A comprehensive review of the existing literature making use of ISMN data is also provided in order to identify current limitations in functionality and data usage and to shape priorities for the next decade of operations of this unique community-based data repository

Urban energetics applications and Geomatic technologies in a Smart City perspective

The management of an urban context in a Smart City perspective requires the development of innovative projects, with new applications in multidisciplinary research areas. They can be related to many aspects of city life and urban management: fuel consumption monitoring, energy efficiency issues, environment, social organization, traffic, urban transformations, etc. Geomatics, the modern discipline of gathering, storing, processing, and delivering digital spatially referenced information, can play a fundamental role in many of these areas, providing new efficient and productive methods for a precise mapping of different phenomena by traditional cartographic representation or by new methods of data visualization and manipulation (e.g. three-dimensional modelling, data fusion, etc.). The technologies involved are based on airborne or satellite remote sensing (in visible, near infrared, thermal bands), laser scanning, digital photogrammetry, satellite positioning and, first of all, appropriate sensor integration (online or offline). The aim of this work is to present and analyse some new opportunities offered by Geomatics technologies for a Smart City management, with a specific interest towards the energy sector related to buildings. Reducing consumption and CO2 emissions is a primary objective to be pursued for a sustainable development and, in this direction, an accurate knowledge of energy consumptions and waste for heating of single houses, blocks or districts is needed. A synoptic information regarding a city or a portion of a city can be acquired through sensors on board of airplanes or satellite platforms, operating in the thermal band. A problem to be investigated at the scale of the whole urban context is the Urban Heat Island (UHI), a phenomenon known and studied in the last decades. UHI is related not only to sensible heat released by anthropic activities, but also to land use variations and evapotranspiration reduction. The availability of thermal satellite sensors is fundamental to carry out multi-temporal studies in order to evaluate the dynamic behaviour of the UHI for a city. Working with a greater detail, districts or single buildings can be analysed by specifically designed airborne surveys. The activity has been recently carried out in the EnergyCity project, developed in the framework of the Central Europe programme established by UE. As demonstrated by the project, such data can be successfully integrated in a GIS storing all relevant data about buildings and energy supply, in order to create a powerful geospatial database for a Decision Support System assisting to reduce energy losses and CO2 emissions. Today, aerial thermal mapping could be furthermore integrated by terrestrial 3D surveys realized with Mobile Mapping Systems through multisensor platforms comprising thermal camera/s, laser scanning, GPS, inertial systems, etc. In this way the product can be a true 3D thermal model with good geometric properties, enlarging the possibilities in respect to conventional qualitative 2D images with simple colour palettes. Finally, some applications in the energy sector could benefit from the availability of a true 3D City Model, where the buildings are carefully described through three-dimensional elements. The processing of airborne LiDAR datasets for automated and semi-automated extraction of 3D buildings can provide such new generation of 3D city models

Land subsidence monitoring with differential SAR interferometry

The potential of differential SAR interferometry for land subsidence monitoring is reported on. The principle of the technique and the approach to be used on a specific case are first presented. Then significant results using SAR data from the ERS satellites for various sites in Germany, Mexico, and Italy, representing fast (m/year) to slow (mm/year) deformation velocities, are discussed. The SAR interferometric displacement maps are validated with available leveling data. The accuracy of the subsidence maps produced, the huge SAR data archive starting in 1991, the expected continued availability of SAR data, and the maturity of the required processing techniques lead to the conclusion that differential SAR interferometry is suitable for operational monitoring of land subsidence

Radar interferometry-based mapping of the present land subsidence along the low-lying northern Adriatic coast of Italy

The northern Adriatic coastal area, Italy (from the Veneto region northward, and to the Romagna region to the south), is characterized by low-lying environments such as lagoons, e.g. those of Venice and of the Valli di Comacchio, wetlands and deltas, such as that of the Po River delta, and reclaimed farmland and beaches subjected to marked anthropogenic pressure. The coastal area is characterized by an elevation generally well below the mean sea level (down to \u20134 m m.s.l.) and never exceeds 2 m above m.s.l. Man-induced land subsidence has greatly affected the whole coastal area over the 20th century, and especially from the 1950s and the 1970s, when over-exploitation of subsurface fluids was responsible for the occurrence of general lowering. Although the sinking rates have significantly decreased over the last decades, land subsidence is still a process threatening the entire coastal environment. In this study we report a recent investigation aimed at mapping the vertical displacements recorded in the period 1992\u20132000 on the 20\u201330 km wide and 250-km long coastal area from the Tagliamento River to the north, to the town of Rimini to the south. Measurements have been carried out by Persistent Scatterer Interferometry (PSI) using levelling and GPS records to reference the interferometric solution. The results identify out the variability of the ground movements that are presently occurring along the northern Adriatic coastline. Substantially stable areas, the most important of which are the cities of Venice and Ravenna and their surroundings, contrast with subsidence rates of more than 10 mm/year recorded in some parts of the Po River delta and to the south. The observed land displacements have been associated with the geological features of the study region, i.e. tectonics and differential consolidation of the Middle\u2013Upper Pleistocene and Holocene deposits, and to anthropogenic activities, mainly groundwater withdrawal from the Upper Pleistocene-Holocene alluvial deposits and more locally peatland oxidation in reclaimed areas and gas exploitation from Plio-Pleistocene reservoirs