1,721,045 research outputs found
Quality check of crisis maps produced over five years by copernicus ems
Full text linkCrisis mapping is a widely used tool for the digital representation of a disaster situation. It provides stakeholders with spatial information of the crisis describing type and severity of damages, impacts on the area and its population. The quality of crisis maps is of great importance since the disaster response depends on the provided information. In some cases, in order to deliver a map on time, its quality can be lower than expected. The evaluation of a big sample of rapid maps produced between 2013 and 2017 and collected from open source Copernicus service has been performed. The quality check has been performed by visual analysis, observing around 36 parameters defined in the validation protocol designed at the Joint Research Centre (JRC) of the European Commission. The overall conclusion is that crisis maps produced during the observed period have shown a good level of quality, that can satisfy the need of the user. Still, there are some parameters that could be delivered with more details and precision. The results are analyzed in details and remarks are presented
GeoMed2,the geoid of the Mediterranean: work in progress
Full text linkGeodesy can provide valuable information on marine current estimation based on the combination of gravity and altimetry. Gravity is standardly used to estimate the geoid undulation, i.e. the height of the geoid over a given reference ellipsoid. As it is well known, the geoid undulation over the oceans is closely related to the Mean Sea Surface (MSS) with discrepancies that can reach 1–2 m at global scale. By satellite altimetry, one can get the MSS and then estimate the Mean Dynamic Topography (MDT) as the difference between the MSS and the geoid undulation. As the MDT is related to the ocean circulation, information on the ocean circulation to be compared with oceanographic estimates can be provided using these geodetic measurements. In this context, the GeoMed2 project aims at estimating a high-accuracy and high-resolution geoid model for the Mediterranean Sea based on land and marine gravity data and on recent Global Geopotential Models. In this paper, the processing methodology based on the well-known remove–compute–restore approach for the determination of the geoid in the Mediterranean area is presented. In a pre-processing step, all available gravity observations for the wider Mediterranean basin have been collected, validated, homogenized, and unified in terms of their horizontal and gravity system. In this way, a reliable gravity database to be used for the determination of the geoid has been prepared. This data set has been used in computing a gravimetric geoid estimate based on which the MDT over the Mediterranean Sea was obtained. The results of this computation were then revised, commented and compared with other existing MDT solutions. By these comparisons, it can be concluded that the geodetic computed MDT is not yet satisfactory since it is too noisy. This is possibly due to some inconsistencies still present in the gravity data used for estimating the geoid undulation and to the adopted MSS which seems to be too smooth over the Mediterranean area
A Spatiotemporal Drought Analysis Application Implemented in the Google Earth Engine and Applied to Iran as a Case Study
Full text linkDrought is a major problem in the world and has become more severe in recent decades, especially in arid and semi-arid regions. In this study, a Google Earth Engine (GEE) app has been implemented to monitor spatiotemporal drought conditions over different climatic regions. The app allows every user to perform analysis over a region and for a period of their choice, benefiting from the huge GEE dataset of free and open data as well as from its fast cloud-based computation. The app implements the scaled drought condition index (SDCI), which is a combination of three indices: the vegetation condition index (VCI), temperature condition index (TCI), and precipitation condition index (PCI), derived or calculated from satellite imagery data through the Google Earth Engine platform. The De Martonne climate classification index has been used to derive the climate region; within each region the indices have been computed separately. The test case area is over Iran, which shows a territory with high climate variability, where drought has been explored for a period of 11 years (from 2010 to 2021) allowing us to cover a reasonable time series with the data available in the Google Earth Engine. The developed tool allowed the singling-out of drought events over each climate, offering both the spatial and temporal representation of the phenomenon and confirming results found in local and global reports
Semantic validation of social media geographic information: A case study on instagram data for expo Milano 2015
Full text linkSocial media data, such as Instagram posts, can be associated with spatial positions. This information can be exploited to perform spatial analyses, such as identifying distribution patterns of points representing the positions of social media users during an emergency or while attending a specific event or exhibition. However, the geolocation provided by Social Media Geographic Information (SMGI) needs to be validated, in order for the spatial data to be used in a meaningful way in subsequent spatial analyses or mapping procedures. In this paper, a case study is presented based on Instagram data collected during the first two months of the Expo Milano 2015 exhibition, where the spatial data have been validated by exploiting the semantic component of the posts
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Crowdsourcing water quality with the simile app
Full text linkThis paper aims at presenting the application for lake water quality monitoring which has been developed in the framework of SIMILE (Informative System for the Integrated Monitoring of Insubric Lakes and their Ecosystems) Interreg Italy-Switzerland project. The objective of SIMILE project is to facilitate the monitoring of the Maggiore, Como, and Lugano lakes through the integration of different techniques: in situ monitoring with buoys, remote sensing and citizen science. A mobile application has been designed in agreement with the project partners, who are also actors working for lake quality monitoring, such as CNR (Italian National Research Council) and ARPA (Agency for prevention and environmental protection). The developed application allows to collect data over the area of interest, such as pictures and parameters which can be acquired by visual inspection as well as with appropriate tools, depending on the user typology. The application has then been implemented with open source software to foster its use also for other projects with similar goals. In the paper, the design choices, the architecture and the implementation details are described
Cross-Sectoral and Multilevel Dimensions of Risk and Resilience Management in Urban Areas Enabled by Geospatial Data Processing
Full text linkThe growing complexity of cities and the unprecedented pace of urbanisation create exposure and vulnerabilities to extreme events and crises that are difficult to manage and plan for as widely acknowledged by the existing literature. In this paper, three main challenges to be tackled are identified based on the selected literature according to the interpretation of the authors based on extended research in the field. Those challenges relate to the multi-risk environment characterising many contemporary cities, the need to overcome sectoral approaches towards increased alignment of emergency and spatial planning at different scales, and the opportunities that derive from integrated risk and resilience management. Such challenges are evidenced in the Pozzuoli case study, a densely inhabited municipality of the metropolitan city of Naples, placed into a volcanic caldera, that has been analysed in the light of the above challenges for an extended period of time of about fifty years. The in-depth assessment of the quality of urban development has been enabled by geospatial data management. Advanced geospatial information systems are not only instrumental in depicting the history of urban development in the period of consideration but also as an enabler to tackle the above-mentioned challenges. In fact, such systems permit a much more dynamic and updatable assessment of multirisk conditions and provide the basis for shared knowledge among the large number of stakeholders that are responsible for different sectoral and comprehensive urban and risk-related plans
A collaborative platform for water quality monitoring: Simile webgis
Full text linkNowadays, the increasing pressure over water resources is reflecting on the water quality all over the globe. Not surprisingly, local, and regional governments are taking initiatives into tackling this issue. However, the management of water resources requires coordinated management by the stakeholders, especially in cross-border regions, to achieve efficient regulations. Then, the data-sharing for monitoring the water resources is fundamental for the stakeholder participation in the process of knowledge building. This work presents the design and implementation of a collaborative web platform aiming at enhancing these processes applied to share water quality parameters maps produced under the framework of the SIMILE (Integrated monitoring system for knowledge, protection and valorisation of the subalpine lakes and their ecosystems) project. The platform takes advantage of open-source infrastructure and standards. The solution provides two web-based applications devoted to the upload/management (customized GeoNode) of the data and its visualization (WebGIS). The scope of the collaborative platform is to improve the access to information for awareness-building on the water resources in the Insubric area
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