Christos Chalkias

Recent Insular Mediterranean Landscape Evolution: A Case Study on Syros, Greece

Abstract Recent changes in the Mediterranean landscape has been triggered by changes in human activities. The first aim of this study is to identify socio-economic factors that brought about land cover change and the way the environmental characteristics of the area defined the trajectory or the lack of change and its spatio-temporal pattern. The second aim is to test whether the landscape is becoming more homogenous due to this process. The study was based on land cover maps of the area of Galissas on Syros, Greece covering the period between 1945 and 1998. The direction and the timing of change (or the lack of it) was related to rural depopulation, the emergence of greenhouse cultivation and tourism growth, and the geology and topography of each site. The underlying environmental heterogeneity has largely retained the land cover heterogeneity by mediating the processes of change.

GIS Supported Landslide Susceptibility Modeling at Regional Scale: An Expert-Based Fuzzy Weighting Method

The main aim of this paper is landslide susceptibility assessment using fuzzy expert-based modeling. Factors that influence landslide occurrence, such as elevation, slope, aspect, lithology, land cover, precipitation and seismicity were considered. Expert-based fuzzy weighting (EFW) approach was used to combine these factors for landslide susceptibility mapping (Peloponnese, Greece). This method produced a landslide susceptibility map of the investigated area. The landslides under investigation have more or less same characteristics: lateral based and downslope shallow movement of soils or rocks. The validation of the model reveals, that predicted susceptibility levels are found to be in good agreement with the past landslide occurrences. Hence, the obtained landslide susceptibility map could be acceptable, for landslide hazard prevention and mitigation at regional scale.

Assessment of the sensitivity of the southern coast of the Gulf of Corinth (Peloponnese, Greece) to sea-level rise

The eustatic sea-level rise due to global warming is predicted to reach approximately 18–59 cm by the year 2100, which necessitates the identification and protection of sensitive sections of coastline. In this study, the classification of the southern coast of the Gulf of Corinth according to the sensitivity to the anticipated future sealevel rise is attempted by applying the Coastal Sensitivity Index (CSI), with variable ranges specifically modified for the coastal environment of Greece, utilizing GIS technology. The studied coastline has a length of 148 km and is oriented along the WNW-ESE direction. CSI calculation involves the relation of the following physical variables, associated with the sensitivity to long-term sea-level rise, in a quantifiable manner: geomorphology, coastal slope, relative sea-level rise rate, shoreline erosion or accretion rate, mean tidal range and mean wave height. For each variable, a relative risk value is assigned according to the potential magnitude of its contribution to physical changes on the coast as the sea-level rises. Every section of the coastline is assigned a risk ranking based on each variable, and the CSI is calculated as the square root of the product of the ranked variables divided by the total number of variables. Subsequently, a CSI map is produced for the studied coastline. This map showed that an extensive length of the coast (57.0 km, corresponding to 38.7% of the entire coastline) is characterized as highly and very highly sensitive primarily due to the low topography, the presence of erosionsusceptible geological formations and landforms and fast relative sea-level rise rates. Areas of high and very high CSI values host socio-economically important land uses and activities.

Landslide susceptibility, Peloponnese Peninsula in South Greece

The aim of this paper is to investigate landslide susceptibility mapping in regional scale, considering the spatial stationarity of the relationship between landslide susceptibility and its influencing factors. Landslides are among the most severe natural hazards and their management has a key role to human safety. During the last decades, a significant number of GIS-based methods for landslide susceptibility assessment and mapping have been proposed in the literature. In this paper, contemporary methods for landslide susceptibility analysis have been applied. The latter include global and local regression analysis aiming to study the relationship between landslide occurrence and its determinants. This paper also examines if this relationship is spatial non-stationary via the application of the Geographically Weighted Regression (GWR). The proposed methodology has been applied in the Peloponnese peninsula, in South Greece. To examine the factors responsible for the occurrence of a landslide event; topographic (slope angle, elevation), geological and other environmental variables (land cover, rainfalls) were considered. The results suggest that GWR provides a potential improvement in landslide susceptibility assessment compared to traditional global regression analysis methods.

Health Care Access and Prevalence of the Metabolic Syndrome Among Elders Living in High-Altitude Areas of the Mediterranean Islands: The MEDIS Study

AIM The aim of the present work was to evaluate the relationships between sociodemographic, clinical, and lifestyle characteristics and the presence of metabolic syndrome, among high and low altitude living elderly individuals without known CVD. METHODS During 2005-2011, 1959 elderly (aged 65 to 100 years) individuals from 13 Mediterranean islands were enrolled. Sociodemographic, clinical, and lifestyle factors were assessed using standard procedures. Metabolic syndrome was defined according to the (Adult Treatment Panel) ATP III criteria. Mountainous areas were defined those more than 400 meters in height. RESULTS For the present analysis 713 men and 596 women were studied; the prevalence of the metabolic syndrome was 29% (24% in men, 35% in women, p < 0.001). Furthermore, the prevalence of metabolic syndrome was 55% in the elders living in mountainous areas, as compared with 26% among those living at sea-level (p = 0.01). Similarly, the prevalence of hypertension, hypercholesterolemia, and obesity were higher in high altitude as compared with low altitude areas (all p-values < 0.01). After adjusting for various confounders, elders living in high altitude areas were 3.06-times more likely to have the metabolic syndrome than those living at sea-level (OR = 3.06, 95%CI 2.02-4.65). However, when the annual number of visits to health care centers was taken into account, the effect of altitude of living was not associated with the presence of the syndrome. CONCLUSIONS A considerable proportion of mountainous living elderly had the metabolic syndrome. Public health actions need to be taken to reduce the burden of cardiometabolic disorders by enabling better access to health care, especially in remote mountainous rural areas.

Monitoring the urban expansion of Athens using remote sensing and GIS techniques in the last 35 years

During the last thirty-five years the capital of Greece has suffered from an enormous internal immigration. Its population has overpassed the five millions and today almost the half population of Greece is squeezed in Athens metropolitan area. Because of the significant increase of population, the urban expansion in the basin of Athens was also excessive and in some cases catastrophic. Buildings have covered all the free places, new roads have been constructed, the drainage networks have been covered or disappeared and a lot of changes have been occurred to the landforms. The construction of the new airport (Elefterios Venizelos) at the beginning of this decade created a new commercial and urban pole at the eastern part of Athens and the constructive activity has been moved to new areas around the airport. Our aim was to detect and map all the changes that occurred in the urban area, estimate the urban expansion rate and the human interferences in the natural landscape, using GIS and remote sensing techniques. We have used satellite images from three different periods (1973, 1992, 2002) and topographic maps of 1:25.000 scale. The spatial resolution of all the satellite images ranges from 5 to 10 meters and is it acceptable for the monitoring and mapping of the urban growth. Supervised classification and on screen digitizing methods have been used in order to map the changes. Finally the qualitative and quantitative results of this study are presented in this paper.

Benefits from GIS Based Modelling for Municipal Solid Waste Management

Waste management issues are coming to the forefront of the global environmental agenda at an increasing frequency, as population and consumption growth result in increasing quantities of waste. Moreover, technological development often results in consumer products of complex composition, including hazardous compounds, which pose extra challenges to the waste management systems and environmental protection at the end of their useful life, which may often be fairly short (e.g. cell-phones and electronic gadgets). These end-of-pipe challenges are coupled with the deepening understanding that the Earth’s natural resources are finite by nature and their current exploitation rate unsustainable, even within a midterm perspective. The self-cleaning capacity of the Earth systems is often also viewed as a «natural resource» under stress, with climate change being the most pronounced expression of this risk. In the context of the above mentioned challenge a New Paradigm for waste management has emerged, shifting attention to resources efficiency and minimisation of environmental impacts throughout the life cycle of waste management, from waste prevention to safe disposal. This is best expressed, but not confined, in the relevant EU policy and legislation (e.g. the Thematic Strategy on the prevention and recycling of waste, the Thematic Strategy on the Sustainable Use of Natural Resources and the revised Waste Framework Directive, WFD-2008/98/EC). Especially the latter is of particular interest as it has a legally binding nature for all EU member states and sets a benchmark which is often also taken into consideration by the waste management systems of non-EU countries. The WFD reaffirms the need to move waste management higher in the so called “waste hierarchy”, preferring, in this order, prevention, reuse, recycling and energy recovery over disposal. Separate collection for dry recyclables in municipal solid waste (MSW) should be implemented while separate collection of biowaste should be promoted (although no specific legislative requirements are set) (Nash, 2009). Overall, EU and national waste management policies and legislation in many parts of the world are becoming increasingly demanding for the providers of these services, namely municipalities and their associations, demanding high recovery and recycling rates for a wide range of materials and goods, high diversion targets for the biodegradable fraction of the waste, advanced treatment processes, long after-care periods for existing and future landfills etc (COM, 2005; Lasaridi, 2009). Moreover, this increased level of service will need to be provided at the minimum possible cost, as the public will not be able to bear large

Application of the SWAT model for the investigation of reservoirs creation

Efficient Water Management is an important factor for regional development and requires a set of actions in order to manage water resources in a sustainable way. This paper describes a methodology of water resources exploitation, with the potential of creating small mountainous and upland reservoirs. This can be done with the integration of Geographic Information Systems (GIS), while using the SWAT hydrological modeling and Reservoir Simulation software. Andros Island was chosen as the study area. This project involves the hydrologic analysis and the assessment of runoff (using SWAT model for a 100 years simulation in the Afrouses basin). In two different selected sites, the feasibility of constructing a dam with the simultaneous creation of a reservoir based on annual failure rates of deliverability of certain volume of water is investigated.

Comparison and evaluation of landslide susceptibility maps obtained from weight of evidence, logistic regression, and artificial neural network models

The main purpose of this study is to compare the performance of two statistical analysis models like weight of evidence and logistic regression (LR) with a soft computing model like artificial neural networks for landslide susceptibility assessment. These models were applied for the Selinous River drainage basin (northern Peloponnese, Greece) in order to map landslide susceptibility and rate the importance of landslide causal factors. A landslide inventory was prepared using satellite imagery interpretation and field surveys. Eight causal factors including altitude, slope angle, slope aspect, distance to road network, distance to drainage network, distance to tectonic elements, land cover, and lithology were considered. Model performance was tested with receiver operator characteristic analysis. The validation findings revealed that the three models show promising results since they give good accuracy values. However, the LR model proved to be relatively superior in estimating landslide susceptibility throughout the study area.

Mapping environmental risks: Quantitative and spatial modeling approaches

In recent years, there has been a growing application of advanced methods and techniques such as geographical information systems (GIS), remote sensing and spatial analysis methods in research aimed at understanding, analyzing and visualizing environmental risks. Areas of interest are particularly focused around climate change: the increase in the frequency of extreme weather conditions; the impact of natural disasters; the change to human development make the latter even more relevant. Progress in computer hardware and software allows the application of mathematically complex and computationally intensive methods over relatively small timescales. This special issue of the Journal of Maps is devoted to recent innovations and techniques in the exploitation of mapping and geoinformatics in the field of Environmental Risk Assessment.