37 research outputs found

    Development of a methodology for spatial composite indicators: a case study on landscape.

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    This thesis proposes a methodology for the construction of spatial composite indicators (SCI). The study starts from the premise that Composite Indicators (CIs) are regarded as very reliable tools to support decision processes. They are usually developed to describe complex phenomena of the reality in various domains, and more specifically, to rank spatial units (usually countries) in which a given indicator is calculated. Despite their wide use and their development, no attention has generally been paid to the spatial dimension of their input data and of their final score. Data are treated as normal statistical sampling, therefore their spatial structure and their spatial importance are considered to be equal across the spatial domain, without considerations about possible spatial variations. Nowadays, this appears to be a serious limit, considering the development of Spatial Data Infrastructures (SDI), which makes a large amount of spatial data available, and the development of spatial statistical techniques implemented in GIS, with combined together offer unprecedented opportunity for the spatialization of CIs

    Ecogeomorphology and vulnerability in a Mediterranean ria-type coast (La Maddalena Archipelago, NE Sardinia, western Mediterranean)

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    This paper presents a map describing the main geomorphological and sedimentological features, hydrodynamics, benthic habitat distributions and human impact on the coastal and marine areas of the Archipelago of La Maddalena (NE Sardinia, western Mediterranean). This cartography is based on an interdisciplinary sea-land approach, with the aim being to support sustainable and successful beach management in the face of a changing climate and environment, thereby contributing to the achievement of the Agenda 2030 Sustainable Development Goals (13, 14 and 15). In the Main Map (1:14,000 scale), the static and dynamic features of the beach systems and adjacent inner shelf are divided into thematic sections that include the geomorphological elements, hydrodynamics, sedimentological distributions, benthic habitat (mainly Posidonia oceanica meadow) and anthropogenic impacts. The map establishes a fundamental, multidisciplinary benchmark that is able to provide substantial scientific support to policymakers in relation to future vulnerability-assessment activities and the definition of land-management strategies

    Geomorphology, beach classification and seasonal morphodynamic transition of a Mediterranean gravel beach (Sardinia, Gulf of Cagliari)

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    This paper presents an innovative multi-thematic map (1:2500) that integrates morpho-sedimentological data, hydrodynamic processes, seasonal morphodynamic transitions and the distribution of the benthic habitat of a Mediterranean microtidal, wave-dominated gravel beach system. It is part of a larger cartography of coastal areas, and is based on an interdisciplinary sea-land approach that is applicable worldwide and aims to facilitate coastal management practices and future scientific research. The applications to coastal management include: the facilitation of coastal vulnerability assessments; easy-to-access, up-to-date digital geospatial data; and baseline studies for the future assessment and monitoring of environmental changes. The main environmental features that control the marine processes of this gravel beach appear to be linked to geological and morphological contexts such as the presence of the river mouth, the outcropping of a beach-rock along the coastline, the deposition of gravelly sediment in the beachface and the seagrass cover

    Natural vs. Anthropic Influence on the Multidecadal Shoreline Changes of Mediterranean Urban Beaches: Lessons from the Gulf of Cagliari (Sardinia)

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    Urban Mediterranean beaches are often characterized by a fragile and unstable equilibrium that can be easily altered by ongoing climate change and by the increase in human pressure. This may pose serious threats to the survival of beach systems that cannot accommodate these modifications. In this paper, the spatio-temporal shift of the shoreline was investigated along two urban beaches in the Gulf of Cagliari (Poetto and Giorgino; southern Sardinia, western Mediterranean Sea) across a time frame of 62 years (1954–2016). The Digital Shoreline Analysis System (DSAS) ArcGIS™ extension was used to extract different statistical parameters which allowed us to quantify the erosion and accretion rates. These data were further examined in relation to a number of anthropic and natural forcings in order to disentangle the factors controlling shoreline evolution. Eight sectors with interchanging net erosive and accretion trends were identified along the Poetto and Giorgino beaches. In six decades, some sectors of the two study sites appeared to have undergone great shoreline modification as a result of the intense anthropogenic activities impacting these coastal areas. The westernmost portions of both beaches were found to be the most vulnerable to erosion processes; such conditions were likely controlled by the interplaying of local hydrodynamics and by the intense coastal development which affected these sectors. The highest retreat rates (mean end point rate (EPR) = −0.51/year) were recorded in the western limit of Giorgino beach. Along the western limit of Poetto beach, EPR erosion rates (mean EPR = −2.92/year) considerably increased in the years after the artificial beach nourishment carried out in 2002, suggesting that the majority of the nourished material was lost offshore or partly redistributed along the beach. Coastal structures, urban development, river catchment modification, industrial and port activities, beach cleaning and touristic and recreational activities have been identified as the ongoing causes of coastal alteration. If these factors remain constant, under projected climate change scenarios, these beaches are at risk of further increased flooding and erosion. In this context, the application of DSAS appeared as an essential tool, supporting a monitoring system able to provide understanding and, potentially, predictions of the short- to long-term evolution of these beach system

    On the role of biomass on coastal morphodynamics in natural and urban Mediterranean beaches

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    The continuous sea level rise and the increase in the intensity of wave storms, amplified by global climate change, implies an adequate response from coastal management and environmental protection. To counter these phenomena, urgent measures should be taken to mitigate anthropogenic impacts and restore natural coastal resilience. This thesis deals with the role that biomasses (mainly Posidonia oceanica and, in some cases, Arundo donax rests) have within three Mediterranean beaches differentiated from each other by more or less marked human impacts. On a beach with almost irrelevant anthropic impacts, the deposition of the banquettes at the end of the most significant wave storms is analysed through a video monitoring system. It has been shown how this phenomenon generates a rapid accretion of the emerged beach, which restores its original extension, reduced during the storm, in two or three days. The spatio-temporal shift of the shoreline was investigated along two others urban beaches in Cagliari Gulf (Southern Sardinia, Italy), through orthorectified photographs, across a time frame of 62 years, in order to quantify and distinguish the factors controlling the shoreline evolution (erosion and/or accretion rates) in relation to a number of anthropic and natural forcings. The evolution of the geomorphological setting of the urban coastal belt of Cagliari was also carried out through a sea-land approach and a multidisciplinary and multi-temporal investigation summarized in a geomorphological map. Furthermore, the results of the water infiltration tests, carried out in different areas of the dry beach, showed that the presence of biomasses, above and inside the sand, considerably increases its permeability. This allows the beach to drain the overwashed water and its return to the sea during the most energetic storm events, limiting runup and flooding extension. Finally, another original contribution of this work is related to the analysis of the banquette deposition and dismantling dynamics, through a four years video monitoring system database in one of the most urbanized portion of the Cagliari beaches. This study looked for a correlation between the wave and wind climate and the dynamics of the banquettes, and the results showed that wave motion plays a more important role in the deposition of the banquettes than in their erosion. For this last process the offshore and inshore winds plays a more significant role than the waves

    Spatial statistics and composite indicators: a review of existing case studies and open research issues on spatial composite indicators

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    Recent research advances in spatial statistic on spatial autocorrelation help to better understand the spatial dependence between spatial units. Understanding this kind of relationships helps to earn better insights on how phenomena are distribute along space and why in a particular location they feature a particular value. In the last decade or so, spatial statistic techniques have been used by several scholars to study the spatial distribution of composite indicators, introducing a new point of view in the study of composite indicators that allows to earn more knowledge with respect to the indicator’s value only; in addition to this, spatial analysis was proven to show, for a particular location, the dependency of the composite from one of its sub-factor. This contribution presents a state of the art review of most recent advances in spatial statistics applied to composite indicators as an early contribution towards a more robust definition and application of spatial composite indicators

    Towards Spatial Composite Indicators: A Case Study on Sardinian Landscape

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    Composite Indicators (CIs) recently earned popularity as decision-support tool in policy-making for their ability to give concise measures of complex phenomena. Despite growing diffusion of the use of CI in policy-making, current research has barely addressed the issue of the spatial dimension of input data and of final indicator scores. Nowadays the spatial dimension of data plays a crucial role in analysis, thanks to recent developments in spatial data infrastructures which has enabled seamless access to a large amount of geographic information. In addition, recent developments in spatial statistical techniques are facilitating the understanding of the presence of spatial effects among data, spatial dependence and spatial heterogeneity. These advances are improving our ability to understand the spatial dimension of information, which is crucial to obtain a more robust representation of the territorial reality and insights of territorial dynamics in order to inform decisions in spatial planning and policy-making. This paper proposes an original method for the integration of spatial multivariate analysis and the use of spatial data to extend existing state of the art methods for CIs, as a step towards the construction of Spatial Composite Indicators. The method was successfully tested on a landscape planning case study

    Planning land-use change for biomass-fuelled energy-production plants: spatial analyses applied to the case of Sardinia, Italy

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    Land-use change in Sardinia is a delicate problem. On the one hand, the Regional Landscape Plan, the main landscape-planning tool adopted on the island, pays great attention to landscape protection, using strict constraints and directives for land management. On the other hand, the Regional Energy Plan aims at the diversification of energy sources and, in particular, of renewable energy sources (RES). Actions directed to the development of RES-based energy production may lead to conflicts between the two plans, especially when the associated land-use changes affect landscapes. The aim of this study is to present a decision-support method for the development of a biomass supply chain that does not compromise landscape values in Sardinia

    Accessibility, rurality and remoteness: an investigation on the Island of Sardinia, Italy

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    The dichotomy between rural and urban settings has been used by census systems across the world in order to distinguish areas with high density population from areas with low density and where the primary occupation is connected to the agricultural sector. In this paper we study the level of accessibility, remoteness and rurality for municipalities in Sardinia, Italy. We apply a spatial analysis by means of indicators, such as accessibility for commuters (De Montis, Caschili and Chessa, 2011), the index of relative rurality, the metropolitan-rural interface levels (Waldorf, 2006) and the rurality- remoteness combined classification (Dijkstra and Poelman, 2008). We investigate whether accessibility shows a similar spatial pattern, with respect to remoteness and rurality, and thus we provide an analysis of the Sardinian setting that is of help for policy-makers and planners to understand some of the relevant regional and urban factors that have driven recent developments

    Accessibility and rurality indicators for regional development

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    The development of a region is affected, inter alia, by concepts linked to the ability to displace and reach other locations (accessibility) efficiently and to lagging economic conditions connected to contemporary countryside activities (rurality). These topics and their relationships have attracted the interest of scholars who have scrutinized the implications of accessibility and rurality for policy making and planning. The aim of this paper is to contribute to the theoretical modeling of accessibility and rurality and to develop an empirical study of their spatial patterns, with reference to the municipalities of the region of Sardinia, Italy. We study accessibility through an indicator constructed using a doubly constrained spatial interaction model and propose the Composite Index of Rurality that aims to evaluate rurality in a regional setting employing multivariate analysis. We investigate the spatial dependence of these indicators through general and local spatial autocorrelation analysis to verify the hypothesis that scarcely accessible spatial units are classifiable as rural areas. The results show that, for the case study of Sardinia, this hypothesis is not always true, as some urban areas are not always highly accessible
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