Object-based image analysis for historic maps classification

Heritage maps represent fundamental information for the study of the evolution of a region, especially in terms of landscape and ecologic features. Historical maps present two kinds of hurdle before they can be used in a modern GIS: they must be geometrically corrected to correspond to the datum in use and they must be classified to exploit the information they contain. This study deals the latter problem: the Historical Cadaster Map, created between 1851 and 1861, for the Trentino region in the North of Italy is available as a collection of maps in the ETRS89/UTM 32N datum. The map is a high resolution scan (230 DPI, 24 bit) of the original map and has been used in several ecological studies, since it provides detailed information not only about land property but also about land use. In the past the cadaster map has been manually digitized and for each area a set of attributes has been recorded. Since this approach is time consuming and prone to errors, automatic and semi-automatic procedures have been tested. Traditional image classification techniques, such as maximum likelihood classification, supervised or un-supervised, pixelwise and contextual, do not provide satisfactory results for many reasons: map colors are very variable within the same area, symbols and characters are used to identify cadaster parcels and locations, lines, drawn by hand on the original map, have variable thickness and colors. The availability of FOSS tools for the Object-based Image Analysis (OBIA) has made possible the application of this technique to the cadaster map. This paper describes the use of GRASS GIS and R for the implementation of the OBIA approach for the supervised classification of the historic cadaster map. It describes the determination of the optimal segments, the choice of their attributes and relevant statistics, and their classification. The result has been evaluated with respect to a manually digitized map using Cohens Kappa and the analysis of the confusion matrix. The result of the OBIA classification has also been compared to the classification of the same map using maximum likelihood classification, un-supervised and supervised, both pixelwise and contextual. The OBIA approach has provided very satisfactory results with the ability to automatically remove the background and symbols and characters, creating a ready to be used classified map. This study highlights the effectiveness of the OBIA processing chain available in the FOSS4G ecosystem, and in particular the added value of the interoperability between GRASS GIS and R

Modeling of forest landscape evolution at regional level: a FOSS4G approach

In the last decades the Alpine landscape has dramatically changed due to social and economic factors. The most visible impact has been the reduction of the population for mid and high altitude villages and the shrinking of the part of the land used for agriculture and grazing, with a progressive reduction of pastures and meadows and the expansion of the forested areas. For these reasons, a dataset describing the forest, meadows and pasture coverage for the Trentino region, in the eastern Italian Alps, has been created. A set of heterogeneous sources has been selected so that maps and images cover the longest possible time span on the whole Trentino region with comparable quality, creating a Land Use/Land Cover (LULC) map based on historical maps from 1859 to 1936 and aerial images from 1954 to 2015. The achieved accuracy ranges from 98% for historical maps to 94% for aereal imagery. The analysis of selected landscape metrics provided preliminary results about the forest distribution and patterns of recolonization during the last 155 years. It has been possible to create future scenarios for the forest evolution for the next 85 years. Given the large number of maps involved, the great flexibility provided by FOSS for spatial analysis, such as GRASS, R, QGIS and GAMA and the possibility of scripting all the operations have played a pivotal role in the success both in the creation of the dataset and in the extraction and modeling of land use change

Effect of water level on migratory birds habitat at lake maggiore

Migratory birds need to stop along their route to rest and feed at so called stopover sites. "Bolle di Magadino"is a protected wetland located near lake Maggiore (CH), an internationally recognized nesting and stop-over site for birds. The waters of Lake Maggiore are important resources for multiple usages, and are artificially regulated through a dam. Even slight variations in the water level are sufficient to cause flooding and draining of large portions of the wetlands, affecting foraging and resting opportunities for birds. We use open data and FOSS4G to study the effect of water level on bird migration. We compared the extent and type of flooded habitat using two approaches: Sentinel-1 remote sensing imagery and simulations based on the measured water level. The effect of type and extent of submerged vegetation obtained with both methods was tested against a time series of bird captures. Both methods had a similar temporal pattern of flooding in autumn, but nearly opposite in spring. The total extent and the type of submerged habitats showed significant differences. The results obtained by simulations based on water level were more correlated to birds captures and species richness than the estimations of flooded habitat derived by with Sentinel-1. The results presented here will contribute to the definition sustainable management tools of water management of lake Maggiore taking into account the effect of lake level on biodiversity

Mapping the recreational value of coppices’ management systems in Tuscany

In recent decades the growing interest in forested areas has led to a higher level of appreciation and consideration regarding the various benefits and services provided by forests. Despite this, when it comes to acknowledging their economic value and their capacity to produce income, the production of timber seems to be the main or even the only function that is considered. However, by adopting a sustainable forest management approach, the value related to non-market forest functions could also be considered. The present paper aims to quantify the potential income related to the recreational value of coppice forest by considering three different management systems: traditional coppice, active conversion to high forest and the natural evolution of forest. In order to do so, a contingent valuation method was used, and 248 forest users were surveyed in the region of Tuscany, Italy. The surveys included a revised price-list method, and the results obtained showed the existence of willingness to pay (WTP) for the maintenance of forests. Users showed a strong preference for conversion to high forest, while natural evolution was the least preferred management option. People’s perception on this matter was also assessed based on their specific location, by georeferencing all of the respondents’ answers: considering this, it was observed that belonging to a municipality located in or close to the mountains (i.e., mountain and natural municipalities) influenced the users’ WTP to maintain natural evolution

Open Source evaluation of kilometric indexes of abundance.

Kilometric Abundance Index (KAI) is a common measure used in wildlife studies because it allows a straightforward comparison of species abundance in different sites or at different times. KAI expresses the ratio of the total number of individuals (or of signs of presence) observed along a transect by the total transect length covered at each site. v.transect.kia is a new tool for GRASS GIS, developed for automating the evaluation of KAI, reducing the risk of manual errors especially when handling large datasets. It can also split the transects according to one environmental variable (typically habitat type) and evaluate true 3D transect length. It calculates KAI using a point map of sightings and saves the results in the attribute table, the output can be displayed in any GIS or used for further statistical analysis. The tool has been tested on field data from Northern Italy for mountain hare (Lepus timidus), allowing a first wide-area estimate

Nasal tip sutures: how to control shape and orientation in rhinoplasty

Nasal tip surgery is universally recognized as the most challenging part of the rhinoplasty procedure. "The tip makes the nose”. Narrowing the anatomically complex alar cartilages can lead to functional and aesthetic unfavourable outcomes. A thorough understanding of the ideal surface aesthetics and contours and spatial relationships of the structures of the nose tip is mandatory. In primary rhinoplasty, a very large percentage of visible tip deformities involve two major areas: the domes and the lateral crura. Suture techniques have the potential to modify the position, shape and definition of the tip. However, even sutures may result in changes beyond the main goals for which they are placed. The final suture effects are influenced by factors such as forces intrinsic to the cartilages, the degree of suture tightening, and limitations posed by the soft-tissue attachments. The closed delivery approach is our favourite. In a step-by-step fashion, first the medial pillar of the tripod should be addressed, establishing stable and strong tip support and basic dome projection symmetry. Subsequently and in our experience, in a standard procedure shaping lateral crura and domes, using reversible techniques that preserve structural integrity of the rimstrip, would be advisable. One of the main goals is not only to narrow the tip but to change the angle of rotation of the lateral crus surface in relation to the sagittal upper septal margin. Once marked the new dome defining point, with a variable combination of the lateral crural steal technique, sutures such as cranial tip sutures (CTS) and hemitransdomal sutures (HTS) might produce the needed outcome of everting and rotating the caudal margin of the lateral crura above the cranial edge. These sutures can gradually increase domal convexity and reduce lateral crura convexity. Additional dome equalization suture can guarantee more symmetry and then one or more lateral crural spanning sutures help in achieving supplementary eversion of the lateral crus. After establishing adequate projection, the tip rotation or position sutures are placed between the cranial edge of intermediate crura and the dorsal septum. The personal association of suture techniques is presented in this study and the long-term subjective and objective results are discussed along with the pros and cons

The challenging Silent sinus syndrome

The Silent sinus syndrome (SSS), first described in 1964 by Montgomery, is considered a relatively rare pathological entity, but it is presumably underdiagnosed and underreported. Terms such as imploding antrum and chronic maxillary atelectasis (CMA) have interchangeably been used to describe this syndrome, even though CMA has been postulated to represent either a different entity or a stage of evolution of the same disease. Bilateral involvement has been documented in a limited number of cases. Silent ethmoid sinus and silent frontal sinus syndromes have been described. The prevalent initial presentation is facial asymmetry with progressive “silent” painless unilateral enophthalmos and hypoglobus, and rarely diplopia. Isolated maxillary sinus hypoplasia must be differentiated. The etiopathogenesis is poorly understood and still under debate. According to the diagnostic criteria, SSS should spontaneously develops in absence of previous trauma or surgery. Secondary SSS to trauma or surgery, or to other causes like inflammation or tumor, has been documented in literature. The diagnosis relies on the CT, which typically shows unilateral hypoplastic and opacified maxillary sinus with inward bowing and remodeling of the sinus walls and inferior displacement of the orbital floor, an enlarged retroantral fat pad, a lateralized uncinate process, and a blocked ostiomeatal complex. The treatment of SSS aims at restoring the eye position and orbital floor height, to prevent progression of enophthalmos, to restore ventilation and drainage of the sinus. These objectives are achieved in single or two-stage surgery. The timing for management of the orbital floor is still under debate.The universally accepted treatment is surgical and usually accomplished by endoscopic sinus surgery. Associated middle turbinate hypertrophy and septal deviation must be previously addressed. Precise and gentle endoscopic removal of the obstruction of the ethmoid infundibulum, simply performing an inferior posteroanterior uncinectomy, since the uncinate process has constantly been found atelectatic and adherent to the lateral nasal wall, can reestablish the patency of the natural maxillary ostium. In our experience, following middle meatal antrostomy, long-term observation with staged orbital surgery, if required, is recommended. In this study, we present our cases with a focus on surgical stratagems developed in order to reduce the risk of injuring the orbit and to achieve long-lasting results