Geomatic Approach Research Articles

Digitalization and Spatial Documentation of Post-Earthquake Temporary Housing in Central Italy: An Integrated Geomatic Approach Involving UAV and a GIS-Based System

Geoinformation and aerial data collection are essential during post-earthquake emergency response. This research focuses on the long-lasting spatial impacts of temporary solutions, which have persisted in regions of Central Italy affected by catastrophic seismic events over the past 25 years, significantly and permanently altering their landscapes. The paper analyses the role of geomatic and photogrammetric tools in documenting the emergency process and projects in post-disaster phases. An Atlas of Temporary Architectures is proposed, which defines a common semantic and geometric codification for mapping temporary housing from territorial to urban and building scales. The paper presents an implementation of attribute specification in existing official cartographic data, including geometric entities in a 3D GIS data model platform for documenting and digitalising these provisional contexts. To achieve this platform, UAV point clouds are integrated with non-metric data to ensure a complete description in a multiscalar approach. Accurate topographic modifications can be captured by extracting very high-resolution orthophotos and elevation models (DSM and DTM). The results have been validated in Visso (Macerata), a small historical mountain village in Central Italy which was heavily damaged by the seismic events of 2016/2017. The integrated approach overcomes the existing gaps and emphasizes the importance of managing heterogeneous geospatial emergency data for classification purposes. It also highlights the need to enhance an interoperable knowledge base method for post-disaster temporary responses. By combining geomatic tools with architectural studies, these visualization techniques can support national and local organizations responsible for post-earthquake management through a 3D modelling method to aid future transformations or interventions following other natural disasters.

Seasonal Variations and Groundwater Quality Assessment for Drinking Purpose in Chengam Taluk of Thiruvannamalai District, Tamil Nadu: A Geomatics Approach

Seasonal Variations and Groundwater Quality Assessment for Drinking Purpose in Chengam Taluk of Thiruvannamalai District, Tamil Nadu: A Geomatics Approach

Appraisal of Ancient Quarries and WWII Air Raids as Factors of Subsidence in Rome: A Geomatic Approach

Ancient mining and quarrying activities left anthropogenic geomorphologies that have shaped the natural landscape and affected environmental equilibria. The artificial structures and their related effects on the surrounding environment are analyzed here to characterize the quarrying landscape in the southeast area of Rome in terms of its dimensions, typology, state of preservation and interface with the urban environment. The increased occurrence of sinkhole events in urban areas has already been scientifically correlated to ancient cavities under increasing urban pressure. In this scenario, additional interacting anthropogenic factors, such as the aerial bombardments perpetrated during the Second World War, are considered here. These three factors have been investigated by employing a combined geomatic methodology. Information on air raids has been organized in vector archives. A dataset of historical aerial photographs has been processed into Digital Surface Models and orthomosaics to reconstruct the quarry landscape and its evolution, identify typologies of exploitation and forms of collapse and corroborate the discussion concerning the induced historical and recent subsidence phenomena, comparing these outputs with photogrammetric products obtained from recent satellite data. Geological and urbanistic characterization of the study area allowed a better connection between these historical and environmental factors. In light of the information gathered so far, SAR interferometric products allowed a preliminary interpretation of ground instabilities surrounding historical quarries, air raids and recent subsidence events. Various sub-areas of the AOI where the presence of the considered factors also corresponds to areas in slight subsidence in the SAR velocity maps have been highlighted. Bivariate hotspot analysis allowed substantiating the hypothesis of a spatial correlation between these multiple aspects.

A GIS Procedure to Assess Shoreline Changes over Time Using Multi-temporal Maps: An Analysis of a Sandy Shoreline in Southern Italy over the Last 100 Years

The aim of the paper is to identify a methodology capable of assessing shoreline changes through a geomatic approach based on the use of GIS (Geographic Information System) software. The paper describes a case study that reports the evolution of a coastline over a period of more than 100 years using medium and large-scale metric maps available in different periods. In fact, the coastlines were obtained from the source maps of the Italian Cadastre (dated 1890), from numerical cartography available on the coastline and acquired in different period at scales 1:5000 and 1:2000 and, more recently, from the Google Earth Pro platform. To analyse the evolution of the coastline a new procedure has been performed which is based on the use of GIS software, in particular a plugin called DSAS that allows the evaluation of the changes in the coastline and also obtains a statistical analysis of its evolution. The results showed the ease and applicability of the method in determining the evolution of the coastline and the strong erosion of a stretch of coastline with important socio-economic consequences and repercussions was highlighted in the analysed case study.

A Geomatic Approach to the Preservation and 3D Communication of Urban Cultural Heritage for the History of the City: The Journey of Napoleon in Venice

The use of historical maps in a digital environment can give considerable support to the study of the history of cities. It allows you to combine information from different sources, processed according to different geomatic techniques, to provide a reconstruction of urban configurations of the past and their comparison with iconographic and textual documentation of the same period. The aim of the research is to try to make the knowledge of a historical event easily accessible by converging within a simple model the various sources on which the reconstruction itself is based. This paper deals with the reconstruction of the ephemeral architecture created for Napoleon’s visit to Venice through the generation of 3D virtual models. The reconstruction was approached through a rigorous method, inserting these models into the context for which they were conceived. The generation of the historical city model, taking advantage of the algorithms of structure from motion applied to photogrammetry, made it possible to compare it with what was shown by the old paintings depicting the event. Virtual models processed within the GIS environment have been uploaded online thanks to the use of WebGIS. We chose to share the research results on the internet to allow users to avail themselves of a space that no longer exists from within it, going beyond the pictorial images of the past, overcoming communication through rendering and videos. The simultaneous application of methods and techniques related to the various components of geomatics within the digital environment has enabled the operation of a faithful reconstruction of reality, bringing to light past urban scenarios that no longer exist and are only known through paintings.

Green Public Areas and Urban Open Spaces Management: New GreenCAL Tool Algorithms and Circular Economy Implications

Urban Open Spaces (UOS) are green infrastructures that provide social and ecosystem services. Green public areas contribute to mitigation and adaptation strategies for addressing climate changes, but their maintenance has a significant cost. Frequent grass cutting operations must be carried out during growing periods to ensure the safe livability of UOS to citizens. In the present paper, a geo database was developed to map green public areas of the city of Latina (Lazio Region, Central Italy) by using a multisource dataset according to the European INSPIRE Directive. The GreenCAL Tool was implemented. Two algorithms to determine UOS extension and the necessary budget for grass cutting operations are used, considering the contribution of different mowing (i.e., mulcher, lawnmower, or brush cutter) and UOS extension itself (~160 ha). The implemented processing chain allowed us to simulate forestation of abandoned areas and potential CO2 sequestration values. Two different scenarios of maintenance programs were also implemented to reduce more than 60% of operational cost according to: (1) different use of UOS; (2) their position within the urban area; (3) guidelines of Italian working group on public green management; and (4) management of vegetal residues. The management of the latter, derived by mowing, contribute to more than 23% of the budget allocated to maintain UOS. Besides the long-term environmental and health perspective, the short-term impact of the present applied research is relevant for a geomatic approach, green public procurements, as well as land use and climate interactions. The alternative management of UOS discussed in the present paper can also reduce organic waste production if the mowing within the UOS is managed as a resource for agriculture rather than urban waste.

A Geomatics Approach in Scan to FEM Process Applied to Cultural Heritage Structure: The Case Study of the “Colossus of Barletta”

Artistic, architectural and Cultural Heritage (CH) structures are often exposed to a high risk of damage caused by seismic events, natural disasters and more by negligence and poor state of preservation and conservation; the use of a series of technologies, based on digital acquisition and high-level data processing, allows the realisation of a three-dimensional model of high detail. In order to preserve structures of particular historical and architectural value, it is necessary to assess their structural stability. In addition, many structures, such as statues, have rather complex geometries. Therefore, it is necessary to identify a methodology able to transform the point cloud generated through a geomatics approach into a model suitable for FEM (Finite Element Analysis) analysis. This process, known as Scan to FEM, is addressed in this paper. The paper shows the case study of the “Colossus of Barletta”, a bronze statue dating back to the 5th century A.D. located in the city of Barletta, Italy. To analyse this structure, a suitable methodology has been developed which is based on the optimisation of the surface model of the structure; in this way, it is possible to obtain an efficient transformation from a digital photogrammetric model with complex geometry into a model suitable for structural finite element analysis. The digital photogrammetry technique was applied for the survey of the structure, which allowed us to obtain a very high-resolution dense point cloud and a geometrically accurate three-dimensional mesh model, i.e., in a TIN (Triangulated Irregular Network) model. Subsequently, the TIN was transformed into a quad mesh model (identifying a suitable reduction value) and finally into NURBS (Non-Uniform Rational Basis-Splines) to be optimised and imported into a finite element calculation software. This geomatics approach has validated an efficient Scan to FEM process; in fact, thanks to this methodology, it is possible to elaborate three-dimensional models with complex geometry and draw a series of considerations related to structural behaviour or specific restoration interventions.

Geomatic Approach to Modelling Urban-Fire-Risk Susceptibility in Akure, Ondo State, Nigeria

Geomatic Approach to Modelling Urban-Fire-Risk Susceptibility in Akure, Ondo State, Nigeria

Measuring Physical access to primary health care facilities in Gambella Region (Western Ethiopia)

Abstract. As part of the project “More equity and quality of health services in Gambella, Gambella Region”, financed by the Italian Agency for Development Cooperation (AICS) and implemented by the Italian NGO Doctors with Africa CUAMM (Padua, Italy) a geographic database of the distribution of health facilities of Gambella Region (western Ethiopia) was created. This data collection was carried out in two missions carried out in February 2018 and November-December 2019. It allowed a mapping of the access roads and the location of health facilities using Geomatic Approaches and related technologies (Remote Survey, Field Survey, GPS, GIS). The field work has allowed the investigation in 11 Waredas (i.e. districts) with the census of 3 primary hospitals, 26 health centres and 121 HPs and related road access by car or, in case of inaccessibility of vehicles, by foot or boat.The final result of this work is the availability of a detailed cartographic picture of the geographical distribution of Health Facilities (HFs) in order to support the modern decision-making tools to be adopted for the distribution of human and instrumental resources. As an example we describe a network analysis performed by ESRI™ Network Analyst which showed the importance of this approach to remodel a more efficient referral system.

Geospatial Correlation Analysis between Air Pollution Indicators and Estimated Speed of COVID-19 Diffusion in the Lombardy Region (Italy).

Background: the Lombardy region in Italy was the first area in Europe to record an outbreak of COVID-19 and one of the most affected worldwide. As this territory is strongly polluted, it was hypothesized that pollution had a role in facilitating the diffusion of the epidemic, but results are uncertain. Aim: the paper explores the effect of air pollutants in the first spread of COVID-19 in Lombardy, with a novel geomatics approach addressing the possible confounding factors, the reliability of data, the measurement of diffusion speed, and the biasing effect of the lockdown measures. Methods and results: all municipalities were assigned to one of five possible territorial classes (TC) according to land-use and socio-economic status, and they were grouped into districts of 100,000 residents. For each district, the speed of COVID-19 diffusion was estimated from the ambulance dispatches and related to indicators of mean concentration of air pollutants over 1, 6, and 12 months, grouping districts in the same TC. Significant exponential correlations were found for ammonia (NH3) in both prevalently agricultural (R2 = 0.565) and mildly urbanized (R2 = 0.688) areas. Conclusions: this is the first study relating COVID-19 estimated speed of diffusion with indicators of exposure to NH3. As NH3 could induce oxidative stress, its role in creating a pre-existing fragility that could have facilitated SARS-CoV-2 replication and worsening of patient conditions could be speculated.

Geomatics approach to assess nesting habitat of green turtles Wadi El Gemal, Red Sea, Egypt

Long-term wave action, sea level rise, climate change, human activities, pollutants, sea surface temperature SST, are causative factors for deterioration and changes in natural ecosystems. The current study aims to assess environmental deterioration that disturbs turtles and their nesting grounds at Wadi El Gemal National Park (WGNP), using modern remote sensing techniques and ecological investigations. Nesting area mapping and change detection were found to be precise and clear in the current investigation. The true nests recorded from WGNP during the current survey were Wadi El Gemal Delta (3), Torfa (10), Elshiekha Sabieha (2), Hankorab (14), Umm Alabas, Wadi El Gemal Island (1) and Syial Island (1). The concentration of some heavy metals in eggshells were positively correlated with their concentrations in sand (p ≤ 0.01), while heavy metals in nesting sands were negatively correlated with grain size (p < 0.05). On the other hand, the distance from vegetation and SST found to interact with the number of nests. Wadi El Gemal Island declined from 1984 to 1990 at a rate of (0.861 %), from 1990 to 2003 at (2.093 %), and (4.059 %) between 2003 and 2016. According to the shift detection review, Syial Island was reduced in area from 1973 to 1984 (−12,523 m2). Wadi El Gemal shoreline accretion was about (16,777 m2) from 1973 to 1984, while erosion was about (16,777 m2) during the same period (393.754 m2). For the entire period (42 years), the overall shift in accretion area was (362,175 m2), while the erosion area was approximately (724.269 m2).

Using Geomatic Techniques to Estimate Volume–Area Relationships of Watering Ponds

Watering ponds represent an important part of the hydrological resources in some water-limited environments. Knowledge about their storage capacity and geometrical characteristics is crucial for a better understanding and management of water resources in the context of climate change. In this study, the suitability of different geomatic approaches to model watering pond geometry and estimate pond-specific and generalized volume–area–height (V–A–h) relationships was tested. Terrestrial structure-from-motion and multi-view-stereo photogrammetry (SfM-MVS), terrestrial laser scanner (TLS), laser-imaging detection and ranging (LIDAR), and aerial SfM-MVS were tested for the emerged terrain, while the global navigation satellite system (GNSS) was used to survey the submerged terrain and to test the resulting digital elevation models (DEMs). The combined use of terrestrial SfM-MVS and GNSS produced accurate DEMs of the ponds that resulted in an average error of 1.19% in the maximum volume estimation, comparable to that obtained by the TLS+GNSS approach (3.27%). From these DEMs, power and quadratic functions were used to express pond-specific and generalized V–A–h relationships and checked for accuracy. The results revealed that quadratic functions fit the data particularly well (R2 ≥ 0.995 and NRMSE &lt; 2.25%) and can therefore be reliably used as simple geometric models of watering ponds in hydrological simulation studies. Finally, a generalized V–A power relationship was obtained. This relationship may be a valuable tool to estimate the storage capacity of other watering ponds in comparable areas in a context of data scarcity.

Assessing site suitability potential for soil and water conservation structures by using modified micro-watershed prioritization method: geomorphometric and geomatic approach

Assessing site suitability potential for soil and water conservation structures by using modified micro-watershed prioritization method: geomorphometric and geomatic approach

Cartographie des déterminants de l’invasion par le pin maritime, Pinus pinaster Ait., de la subéraie de Haddada dans le nord-est de l’Algérie

Plusieurs subéraies du Nord-Est algérien sont sujettes à une invasion par le pin maritime. Cette dynamique forestière qui a débuté dans les années 1980 est souvent citée parmi les facteurs de dégradation des subéraies algériennes mais n’a encore jamais fait l’objet de recherche. L’objectif de notre étude, qui porte sur le cas de la subéraie de Haddada (wilaya d’El-Tarf), était d’identifier les déterminants de l’invasion par le pin maritime, Pinus pinaster Ait., en recourant à une cartographie chorologique de facteurs tels que la pente, l’exposition et les surfaces incendiées en 1994, ainsi qu’une cartographie de la subéraie avant et après l’invasion. L’élaboration des cartes a suivi une approche géomatique complétée par des enquêtes sur le terrain. La cartographie montre que les parties envahies par le pin maritime sont celles qui ont été le plus touchées par l’incendie de 1994, ce qui correspond aussi aux pentes fortes et très fortes. La faible résilience du chêne-liège, Quercus suber, dans ces conditions a permis au pin maritime de le supplanter. Cette dynamique illustre bien le paradigme patch dynamics dans une forêt méditerranéenne, et nous renseigne aussi sur le potentiel invasif du pin maritime, s’agissant d’une espèce se révélant également invasive ailleurs dans le monde. Le changement climatique risque d’accentuer ces processus d’invasion.

Water Erosion Mapping by RUSLE: A Geomatic Approach by GIS and Remote Sensing in the Oued Isser Watershed, Tlemcen, Algeria

Prolonged water erosion leads to severe soil degradation, with highly visible scars. Consequently, the quantitative and descriptive estimation by mapping of the phenomenon has become the main objective of a great deal of research. It is this perspective that this study takes, based on the Revised Universal Soil Losses Equation (RUSLE) for a relatively accurate estimate, by integrating Arc‑GIS tools and remote sensing using high spatial resolution (10 m) image from the Sentinel‑2A satellite. The model uses data on precipitation, soil, topography and vegetation cover management. The methodological approach taken implements this model in order to optimize its use by the various potential users in their planning and decision‑making studies. An application was carried out in the Oued Isser watershed (Tlemcen, Algeria). Soil loss maps were produced and the results indicate a high variation in soil losses in the study area and show that the highest values are concentrated on steep slopes, hence the great influence of the topographic parameter relative to other factors in the model.

Geomatic multiscale approach for the conservation of archeological sites: the case of Alba Fucens (L’Aquila-Italy)

The archaeological site of Alba Fucens (L’Aquila, Italy) (303 BC) is the largest archaeological area of the whole Apennines. Extension, location and environmental context of the site require new methods for risk mitigation and conservation. In this paper, a multiscale geomatic approach, based on remote sensing and UAV photogrammetry, is reported. The main purpose is the extraction of architectonic and weathering information, useful for a better fruition and conservation. For a multiscale approach, very high resolution satellite images (WorldView2) and UAV Photogrammetry technique have been used. The satellite image processing, performed by Normalized Difference Vegetation Index (NDVI), High-pass filter, Principal Component Analysis (PCA) and classification, allowed to detect buried or emerging structures and to estimate fire and erosion risks.On the other hand, UAV photogrammetry technique allowed to evaluate detailed architectural information of the buried (ima, media and summa caveae) and excavated amphitheatre structures (arena, podium and steps). Furthermore it was also possible to systematically acquire complete and reproducible data on stone materials (limestones) and their weathering (loss of stone material, natural or anthropogenic break out, deposits, efflorescences, dark or light crusts, biological colonization, granular and crumbly disintegration, flaking and fissures).With a multiscale and metric approach, the geomatic techniques allow to deeply investigate the monument-mapping and to create a detailed 3D models. In this way, the stone decay, the risks and their mechanisms can be evaluated, in order to plan and perform future actions and interventions for their mitigation.

A novel geomatics method for assessing the Haughton impact structure

AbstractTerrestrial impact structures are typically modified by erosion, burial, and tectonic deformation. Their systematic morphologies are typically reconstructed through a combination of geological and topographic mapping, satellite imagery, and geophysical surveys. This study applies a novel geomatics approach to assessment of the morphology of the extensively studied Haughton impact structure (HIS), Devon Island, Nunavut, in order to test its potential to improve the accuracy and quality of future impact structure reconstruction. This new methodology integrates HIS lithological data, in the form of digitized geologic mapping, with a digital elevation model, within diametrically opposed, wedge‐shaped couplets, and plots these data as pseudo cross sections that capitalize on the radial symmetry of the impact structure. The pseudo cross sections provide an accurate reconstruction of the near‐surface stratigraphic sequences and terraces in the faulted annulus of the modified crater rim. The resultant pseudo cross sections support current interpretations regarding the 10–12 km diameter of the transient cavity, and successfully reproduce the visible outer ring and intermediate uplifted zone within the central basin. Observed positions of vertical offsets suggest that the extent of impact deformation extends beyond the current estimates of the apparent crater rim to radial distances of between 14 and 15 km. Finally, the new geomatics approach provides an improved determination of the spatial, stratigraphic, and temporal relationships among the Haughton Formation lake sediments, allochthonous crater‐fill impactites, and uplifted target rocks, and indicates that there was a not‐insignificant time gap between the formation of the impact structure and the deposition of the sediments.

Effectiveness of a soil mapping geomatic approach to predict the spatial distribution of soil types and their properties

A soil map (1:50,000 scale) was recently produced in Sardinia (Italy) using a cost-effective GIS approach. In this study we aimed to verify, in two pilot areas and by means of statistical analysis, the effectiveness of the adopted methodology in representing and predicting the spatial distribution of soil types and properties. We focused on evaluation of 1) the influence of landforms and parent materials on soil types (WRB Reference Soil Groups) and selected soil properties and 2) the suitability of the adopted methodology for calibrating a model to predict land unit composition in terms of different soil types.Leptosols, Regosols and Cambisols were prevalent on slopes, with Leptosols being more frequent on convex slopes and Regosols and Cambisols on concave slopes. In flat areas, soil types mainly depended on the type and age of parent material, with Regosols and Cambisols prevailing on Holocene deposits and highly developed soils (mainly Luvisols) largely prevailing on Pleistocene deposits. On hard rock, Leptosols were very frequent on terrigenous metamorphic rock and frequent on granite. Besides Leptosols, Regosols occurred more frequently than Cambisols on both parent materials. Landforms strongly influenced soil depth and available water capacity. Soils on plains were deeper than those on slopes, where convex forms had shallower soils than concave forms. A similar trend applied to the available water capacity. The parent material had a significant effect on topsoil properties (thickness, texture, pH and organic carbon content) of soils belonging to the same WRB Reference Soil Group (analysis done on the most relevant WRB Reference Soil Groups, i.e. Leptosols, Regosols and Cambisols).We calibrated and tested stepwise multiple linear regressions (MLR) and general linear models (GLM) to predict the composition of map units in terms of different WRB Reference Soil Groups. The two models gave very similar results, with distinct distribution patterns that were coherent with the relationships observed between soil groups and specific combination of terrain attributes and parent materials. Results showed that both models were more reliable in predicting the absence rather than presence of a given soil type.

On the Combination of Remote Sensing and Geophysical Methods for the Digitalization of the San Lázaro Middle Paleolithic Rock Shelter (Segovia, Central Iberia, Spain)

This paper is focused on the Middle Paleolithic rock shelter called “Abrigo de San Lázaro”, placed in the Eresma River valley (Segovia, Spain). In this area, a multisource geomatic approach is used. On the one hand, the external envelope of the shelter has been digitalized by the means of an efficient combination between aerial photogrammetry and laser scanning (static and mobile). On the other hand, the ground penetrating radar and the electric tomography were used with the aim of evaluating the inner disposition of the shelter. The combination of both digitalization (external and internal) has allowed for improving the knowledge of the site characteristics that, in turn, will facilitate the future excavation works. The results of these studies allow archaeologists to know new data for a better understanding of the site formation (geology of the site, sedimentary potential, rock shelter dimensions, etc.) and the events that took place in it (knowing its historical evolution, especially the interaction between man and the environment). Additionally, the information obtained from these studies is very useful to plan future excavation works on the site.

Environmental analysis of soil characteristics in El-Fayoum Governorate using geomatics approach.

The present study aims at identifying the impact of wastewater irrigation on soil characteristics of El-Fayoum Governorate using Landsat images and geo-statistical techniques integrated with field investigation and soil analyses. Soil samples were collected from 40 representative sites during November/December 2016 and analyzed for pH, electric conductivity (EC), organic carbon (OC), total nitrogen (TN), total phosphorus (TP), Ca, K, Na, and Mg. Landsat images were processed to produce spectral indices of water (MNDWI), vegetation (NDVI), salinity (NDSI), and urban areas (NDBI). Inverse distance weighting in ArcGIS 10.1 was used for mapping soil characteristics. Results refereed to a fluctuation in soil characteristics among different districts, as a result of variation and severity of activities. High levels of OC (3.5-5.21%) were recorded in several scattered parts while northern parts showed high levels of TP and TN recording 0.8-1.7mg/g and 1.7-2.4mg/g respectively. A great fluctuation in salinity, Ca, K, and Na levels were detected among the collected soil samples. Southern and eastern borders of the governorate showed high levels of Ca (> 17.7mg/g). The most alkaline soil samples (> 8) were mostly recorded in El-Fayoum and Tamia districts. Variation of soil characteristics is greatly impacted by irrigation using wastewater particularly from El-Bats and El-Wadi drains. A strong positive correlation (0.94) was observed between urbanization (NDBI) and land salinization (NDSI) which ensures the negative impact of residential areas on agricultural lands. It can be concluded that the agricultural land problems have greatly been impacted by the lack of sufficient water supply. Geospatial techniques along with soil analyses facilitate studying such problems.