Christos A. Karavitis

Agricultural University of Athens · Department of Natural Resources Management and Agricultural Engineering (NRM&AE)

The ever-increasing need for water, the alteration in the climate, and its observed changes over recent years have triggered a lot of research studies associated with the phenomenon of drought. Within the wider geographical region of the Mediterranean, the relevant scientific subject seems to be of great interest, since it is undoubtedly related to...

Energy and water are two of the most important components required to ensure prosperity and sustainable development to societies. This paper aims to review the status of renewable energy desalination for Greek islandic communities, deployed in two axes. The first one reviews the desalination systems state of the art technological solutions, their e...

Natural resources degradation poses multiple challenges, particularly to environmental and economic processes. It is usually difficult to identify the degree of degradation and the critical vulnerability values in the affected systems. Thus, among other tools, indices (composite indicators) may also describe these complex systems or phenomena. In t...

The scope of the present research is to assess drought events using the Standardized Precipitation Index (SPI), which can provide accurate results of drought features on a spatiotemporal scale for Greece. The climate in Greece is a typical northern Mediterranean, with most of the rainfall events noted throughout the period between November and Apri...

Droughts are mainly caused by rainfall deficiencies and high evapotranspiration rates. This article introduces a Factual Drought Index (FDI) as a composite index, based on precipitation and potential evapotranspiration (PET). Its innovation lies in the fact that it does not consider the total PET, but only the amount of PET that exceeds or falls be...

Natural resources are gradually coming under continuous and increasing pressure due to anthropogenic interventions and climate variabilities. The result of these pressures is reflected in the sustainability of natural resources. Significant scientific efforts during the recent years focus on mitigating the effects of these pressures and on increasi...

The Environmentally Sensitive Areas (ESA) Index estimates a region's vulnerability to desertification through the analysis of various parameters, such as soil, geology, vegetation, climate, and anthropogenic activities. Each of these parameters is categorized and every factor presents its own weightings for each category. ESAI index is divided into...

The questions of scale, limit, and areal extent are central points for any drought assessment effort. Drought indices, such as the Standardized Precipitation Index (SPI) and the Standardized Precipitation Evapotranspiration Index (SPEI), are assisting to demarcate drought characteristics and spatial extent. The current approach utilizes the E-OBS g...

The terms ‘resilience’ and ‘vulnerability’ have been widely used, with multiple interpretations in a plethora of disciplines. Such a variety may easily become confusing, and could create misconceptions among the different users. Policy makers who are bound to make decisions in key spatial and temporal points may especially suffer from these misconc...

The Humanitarian Agents (HAs), are among the first entities dealing with the impacts of natural and man-made disasters. This is more than essential in areas, where the National governments and associated economies are either overwhelmed to respond or unprepared to act. Under such pressing conditions, the agents, as any other similar entity, depend...

Desertification constantly and diachronically manifested itself as one of the most critical environmental issues to be confronted and mitigated by society. This work presents the development of a land desertification risk Expert System (ES) for assessing the application of different land management practices by utilizing indicators through a desert...

The degradation of natural resources at an intense rate creates serious problems in the environmental systems particularly with the compounding effects of climatic vagaries and changes. On the one hand, desertification is a crucial universal, mostly an anthropogenic environmental issue affecting soils all over the world. On the other hand, drought...

Drought is a complex natural hazard with its adverse multifaceted impacts cascading in every physical and human system. The vulnerability magnitude of various areas to drought mostly depends on their exposure to water deficiency, the existing water management policy framework and its implementation. The Standardized Drought Vulnerability Index (SDV...

Indices are used for representing complex phenomena; however, concerns usually arise regarding their objectivity and reliability, particularly dealing with their uncertainties during the development process. The current overarching objective is to reveal the significance of employing different weighting techniques in the application of the Standard...

In an era when many water systems worldwide are experiencing water stress regarding water quantity and quality, water reuse has received growing attention as one of the most promising integrated mitigating solutions. Nevertheless, the plethora of technologies and their combinations available, as well as social, economic, and environmental constrain...

Any attempt for the application of integrated drought management, requires identifying and characterizing the event per se. The questions of scale, boundary, and of geographic areal extend are of central concern for any efforts of drought assessment, impacts identification, and thus of drought mitigation implementation mechanisms. The use of drough...

Groundwater level knowledge is one of the crucial information for sustainable use of groundwater resources and efficient and effective conjunctive management of surface and groundwater resources. Despite the fact that there is an increase of water related datasets collected, still groundwater information remains one of the Achilles heel in terms of...

The study aims to evaluate the performance of different empirical soil erosion models (EPM, USLE, Koutsoyiannis and Tarla, RUSLE) in mountainous Mediterranean-type catchments. The study area comprises the Arachthos, Kalamas, Upper Acheloos and Venetikos river basins, located in northwestern Greece. The methodology followed includes both qualitative...

This study refers to hydrogeological conditions that dominate in the closed basin of Vagia of Viotia with emphasis on groundwater quality. It highlights the environmental problem of the region, associated with floods, phenomenon which occurs every year and lasts throughout the wet season. This, results in flushing undesirable substances from the te...

Reclaimed water is receiving growing attention worldwide as an effective solution for alleviating the growing water scarcity in many areas. Despite the various benefits associated with reclaimed water, water recycling and reuse (WR&R) practices are not widely applied around the world. This is mostly due to complex and inadequate local legal and ins...

In here we present a modified version of the RUSLE model, which can perform better than the original version at mountainous, Mediterranean catchments. A weighing coefficient is assigned at each factor in the model resulting into a reduction in the model residuals (difference between modeled and observed sediment yield). Observations are based on se...

This study investigates the relationship between fine resolution, local-scale biophysical and socioeconomic contexts within which land degradation occurs, and the human responses to it. The research draws on experimental data collected under different territorial and socioeconomic conditions at 586 field sites in five Mediterranean countries (Spain...

The study aims to evaluate soil erosion and investigate its spatial distribution by applying two empirical models, namely the Erosion Potential Model (EPM), also known as Gavrilovic method, and the RUSLE model at Venetikos River catchment, the largest and most important tributary of Aliakmonas River, located at Western Macedonia, Northern Greece. T...

In the present study we used ground and satellite meteorological data of the year 2014 from the region of Viotia-Greece. The ground data were obtained from the automatic grass reference evapotranspiration station (AAS) of the Agricultural University of Athens. The satellite data (SAT) cover an area of 0,25 ο x 0,25 ο that includes the AAS. By using...

Considering water resource scarcity and uncertainty in climate and demand futures, decision-makers require techniques for sustainability analysis in resource management. Through unclear definitions of "sustainability", however, traditional indices for resource evaluation propose options of limited flexibility by adopting static climate and demand s...

Soil degradation and desertification processes in the Mediterranean basin reflect the interplay between environmental and socioeconomic drivers. An approach to evaluate comparatively the multiple relationships between biophysical variables and socioeconomic factors is illustrated in the present study using the data collected from 586 field sites lo...

The impact of land management practices on soil erosion and land degradation was assessed during three consecutive years (December 2008–November 2011) in a rural area sensitive to desertification (Crete, Greece). The area is characterized by soils formed on flysch parent material, dry sub-humid climate with water deficit concentrated in summer, and...

Natural resources management needs to deal with multiple and usually conflicting issues in order to satisfy equally opposing objectives for the physical systems sustainable development. In such a complex field, decision making may become quite challenging and pressing particularly in times of crises, such as environmental and climatic uncertainties...

The current work presents the application of the seasonal Auto Regressive Integrated Moving Average Model (ARIMA) using the Standard Precipitation Index (SPI) as a drought indicator and then depicting the spatial distribution through geo-statistical methods. Greece is very often facing the hazardous impacts of droughts, hence presenting an almost i...

Most climate projections predict that average surface temperature and precipitation variability will increase at the global scale, triggering hydrological variations and alterations in river flows and groundwater table levels. Climate change impacts on freshwater resources are likely to affect freshwater availability and quality and by extension, t...

A multivariate linear model is tested in the Viotikos Kefissos basin to estimate monthly and annual average values of precipitation using two different datasets. The model results are validated using all available data. Three independent variables are used to estimate monthly and annual average precipitation. The first independent variable is the e...

Drought is a complex natural phenomenon that lacks a universally accepted definition, thus it is difficult to confront holistically. Several efforts have been made towards managing the widespread and catastrophic drought impacts. In this quest, the concept of vulnerability to drought seems to offer some significant potential. In the present attempt...

An approach to derive relationships for defining land degradation and desertification risk and developing appropriate tools for assessing the effectiveness of the various land management practices using indicators is presented in the present paper. In order to investigate which indicators are most effective in assessing the level of desertification...

Indicator-based approaches are often used to monitor land degradation and desertification from the global to the very local scale. However, there is still little agreement on which indicators may best reflect both status and trends of these phenomena. In this study, various processes of land degradation and desertification have been analyzed in 17...

The forest opening-up constitutes one of the most significant human, interventions in the forest ecosystem. The purposes of such an activity are both the management and the development of those ecosystems as well as the fulfillment of other economic activities such as the transportation of people (including tourism) and goods. Nevertheless, that ac...

Abstract: Population and industry growth in dry climates are fully tied to significant increase in water and energy demands. Because water affects many economic, social and environmental aspects, an interdisciplinary approach is needed to solve current and future water scarcity problems, and to minimize energy requirements in water production. Such...

It has become increasingly clear that desertification can only be tackled through amulti-disciplinary approach that not only involves scientists but also stakeholders. In the DESIRE project such an approach was taken. As a first step, a conceptual framework was developed inwhich the factors and processes thatmay lead to land degradation and deserti...

Soil degradation and desertification processes in the Mediterranean basin reflect the interplay between environmental and socioeconomic drivers. An approach to evaluate comparatively the multiple relationships between biophysical variables and socioeconomic factors is illustrated in the present study using the data collected from 586 field sites lo...

The main objective of this study is to apply the RUSLE to the Venetikos River catchment, located at Western Macedonia, Northern Greece, in order to estimate soil erosion and investigate its spatial distribution. The model was implemented in a GIS environment, taking into account the spatial variation of its individual factors. Sediment yield result...

The need for reliable estimates of soil loss under different land management practices (LMPs) is becoming imperative in the Mediterranean basin to inform decisions on more effective strategies for land management. The effect of LMPs on soil erosion and land degradation has been investigated using experiments from November 2008 to November 2011 in a...

This study aimed to assess the performance of nine empirical methods [FAO-24 Penman (1977), Makkink (1957), Turc (1961), Penman (1963), Priestley-Taylor (1972), Linacre (1977), Kimberly Penman (1982), Hargreaves-Samani (1985), Turc (1961), Penman (1963), Priestley-Taylor (1972), Linacre (1977), Kimberly Penman (1982), Hargreaves-Samani (1985), Copa...

The use of standardised precipitation index (SPI) may lead to an understanding of a droughts magnitude and duration and thus contributing to integrated drought management options. Greece, a semi-arid country, has very often faced the hazardous impacts of droughts. The worst drought on record lasted from 1989 to 1993, and affected all the country, p...

This effort discusses and evaluates alternative water management options to alleviate water stress and meet water needs in insular entities of the Aegean Archipelago, within the framework set by the principles of Integrated Water Resources Management (IWRM) and of the Water Framework Directive 2000/60/EC. Options are presented and assessed to deter...

The Environmental Vulnerability Index (EVI) was developed by the Pacific Islands Applied Geoscience Commission as a global composite index that quantifies the vulnerability of an area's environment. Greece has been selected as reference area due to its current physical and anthropogenic conditions that may lead to environmental instabilities in the...

The main premise of the current effort is that the use of a drought index, such as Standardized Precipitation Index (SPI), may lead to a more appropriate understanding of drought duration, magnitude and spatial extent in semi-arid areas like Greece. The importance of the Index may be marked in its simplicity and its ability to identify the beginnin...

Freshwater is no longer taken for granted as a plentiful, always available, resource. More and more people in an increasing number of countries are experiencing scarcity situations, particularly revealed by droughts. EU Member States are not an exception. Today, many European countries are subject to waves of water deficit that affect their populat...

Desalination powered by renewable energy sources (RES) is presented as an alternative option for the water supply augmentation in the semi-arid region of the island of Rhodes. The case study was chosen as the island relies mostly on the exploitation of groundwater resources and faces serious water shortage problems in an already stressed environmen...

Desertification is the consequence of a series of important degradation processes in semi-arid and arid regions, where water is the main limiting factor of land use performance on ecosystems. Environmental indicators can facilitate the assessment and monitoring of desertification by providing synthetic information on the status and trends of enviro...

The present approach has a two-fold emphasis. On one hand, water supply options are modeled and the optimal combination is presented through the identification of the least cost water supply scheme. On the other hand the results may be used towards the delineation of sustainable environmental policy options, particularly in the vulnerable system of...

The present paper tries to estimate the surface water resources potential in some of the major Aegean islands in an effort to provide a means for the continuous development of the region, and, by extension, for similar areas around the world. The islands have to confront the challenge of surviving in a semiarid environment under the constraints of...

Drought constitutes a rather severe hazard to all human activities, and especially to water supply. After numerous efforts to improve planning and management actions against droughts, many deficiencies still remain. The major new challenge is the development of integrated, comprehensive, and effective drought management schemes, with the aid of dec...

Droughts are ubiquitous phenomena presenting nascent obstacles for any planning and management efforts. Such difficulties may emanate from the fact that the pertinent efforts try to incorporate physical processes as well as highly complex interactions with the surrounding environment. The Athens metropolitan area, in Greece, has recently suffered t...

Drought constitutes a rather severe hazard to all human activities, and especially to water supply. There are numerous efforts for planning and management actions against droughts, nevertheless, deficiencies still pertain in such attempts. The resulting major challenge concentrates on the development of comprehensive and effective drought managemen...

Drought is a dynamic phenomenon seemingly difficult to confront. Nascent sources of difficulties in applying appropriate management responses may be derived from the following causes of confusion: elusive drought definitions; diversified and devastating drought impacts; and absence of systematic response mechanisms. The basic premise of the present...

Forecasting is one of the most important elements in fire and flood danger confrontation schemes for wildland and urban interface areas. The difficulty in studying such natural hazards in general, and in the islands of the Aegean Archipelago in particular, includes not only an assessment of their causes, territorial distribution and damage inflicte...