Time filter

Source Type

Thessaloníki, Greece

Louette G.,Research Institute for Nature and Forest | Maes D.,Research Institute for Nature and Forest | Alkemade J.R.M.,Netherlands Environmental Assessment Agency | Boitani L.,University of Rome La Sapienza | And 14 more authors.
Journal for Nature Conservation | Year: 2010

Human-induced pressures are known to be one of the main causes of biodiversity loss. In order to readily assess policy impacts on biodiversity, a cost-effective evaluation tool is developed, using species sensitivity scores. We demonstrate the potential effects of a selected policy option, being woody bioenergy crop production, on a wide range of species groups in Europe. Large-scale expansions of woody biofuel plantations would have a net negative effect on the species set covered in our study, with little variation among biogeographical regions, but with considerable differences among species groups. The evaluation tool enables policy makers to assess the potential impact of decisions on future biodiversity. © 2009 Elsevier GmbH. All rights reserved. Source

Vougioukas S.,Aristotle University of Thessaloniki | Papamichail D.,Aristotle University of Thessaloniki | Georgiou P.,Aristotle University of Thessaloniki | Papadimos D.,Greek Biotope Wetland Center
Computers and Electronics in Agriculture | Year: 2011

This paper presents an innovative river discharge monitoring system which uses a horizontal acoustic Doppler current profiler (H-ADCP) attached to a mechatronic system that provides vertical motion to different depths. Also, an extended index velocity method is developed which utilises velocity measurements from different depths to achieve more accurate discharge calculation under complex flow conditions. The prototype system was developed and installed near the estuaries of a river where backwater and tidal motion was known to be present due to small distance and altitude difference from the sea. Five experiments were performed, and in two experiments the proposed method performed roughly the same as the standard index velocity method. In the other three experiments the proposed method performed much better and the difference between the discharges was as large as 10%. The results indicate that a vertically moving H-ADCP can be used to calculate river discharge more accurately in complex flow environments. © 2011 Elsevier B.V. Source

Riegels N.,DHI | Riegels N.,Technical University of Denmark | Pulido-Velazquez M.,Polytechnic University of Valencia | Doulgeris C.,Greek Biotope Wetland Center | And 4 more authors.
Journal of Water Resources Planning and Management | Year: 2013

Economic theory suggests that water pricing can contribute to efficient management of water scarcity. The European Union (EU) Water Framework Directive (WFD) is a major legislative effort to introduce the use of economic instruments to encourage efficient water use and achieve environmental management objectives. However, the design and implementation of economic instruments for water management, including water pricing, has emerged as a challenging aspect of WFD implementation. This study demonstrates the use of a systems analysis approach to designing and comparing two economic approaches to efficient management of groundwater and surface water given EU WFD ecological flow requirements. Under the first approach, all wholesale water users in a river basin face the same volumetric price for water. This water price does not vary in space or in time, and surface water and groundwater are priced at the same rate. Under the second approach, surface water is priced using a volumetric price, while groundwater use is controlled through adjustments to the price of energy, which is assumed to control the cost of groundwater pumping. For both pricing policies, optimization is used to identify optimal prices, with the objective of maximizing welfare while reducing human water use in order to meet constraints associated with EU WFD ecological and groundwater sustainability objectives. The systems analysis approach demonstrates the successful integration of economic, hydrologic, and environmental components into an integrated framework for the design and testing of water pricing policies. In comparison to the first pricing policy, the second pricing policy, in which the energy price is used as a surrogate for a groundwater price, shifts a portion of costs imposed by higher water prices from low-value crops to high-value crops and from small urban/domestic locations to larger locations. Because growers of low-value crops will suffer the most from water price increases, the use of energy costs to control groundwater use offers the advantage of reducing this burden. © 2013 American Society of Civil Engineers. Source

Keramitsoglou I.,National institute for astrophysics | Stratoulias D.,National institute for astrophysics | Stratoulias D.,Hungarian Academy of Sciences | Fitoka E.,Greek Biotope Wetland Center | And 2 more authors.
International Journal of Applied Earth Observation and Geoinformation | Year: 2015

Wetland mapping using Earth observation (EO) data has proved to be a challenging task for practitionersdue to the complexity in the spatial structure and composition, the wide within-class spectral variabilityand the absence of easily distinguishable boundaries between habitat types. Furthermore, the inherenttemporal water instability of these landscapes poses an obstacle to the integration of field data withremote sensing data, which also are not acquired simultaneously at all times. To cope with these limitations we tested the applicability of the Kernel-based reclassification (KRC)algorithm on very high spatial resolution (VHR) satellite imagery over a wetland. A composite multi-temporal (i.e. dual-date) VHR WorldView-2 image consisting of spectral bands and indices derived fromtwo images acquired during flooded and dry water conditions were employed. This dataset stresses theseasonal variations of the habitat in response to environmental changes (i.e. flooding) occurring betweenthe two acquisition dates. Multi-temporal imagery is an important information source for fine mappingof wetlands such are river deltas. A multi-temporal approach could reveal even more specific informationduring the phenology of these habitats. The methodology was applied firstly to Axios and then to Aliakmonas river deltas in Northern Greece. The results revealed an overall accuracy of 53% in the first and more complex site, and 86% in the secondsite. © 2014 Elsevier B.V.. Source

Doulgeris C.,Greek Biotope Wetland Center | Georgiou P.,Aristotle University of Thessaloniki | Papadimos D.,Greek Biotope Wetland Center | Papamichail D.,Aristotle University of Thessaloniki
Journal of Environmental Management | Year: 2012

The ability to apply an ecosystem approach to the Strymonas River catchment was investigated using the MIKE 11 modeling system for the simulation of surface water. The Strymonas River catchment is shared mainly between Bulgaria and Greece. The river feeds the artificial Lake Kerkini, a significant wetland ecosystem, and further downstream it outflows to the Gulf of Strymonikos, whose estuary ecosystem is very important for fisheries, biodiversity and tourism. MIKE 11-NAM was used for the simulation of rainfall-runoff process in the Strymonas River catchment and MIKE 11-HD was used to simulate the unsteady flow of the Strymonas River and to apply management rules based on the water level of Lake Kerkini. Two water level management scenarios were investigated. The first scenario referred to the mean daily-observed water level of Lake Kerkini between 1986 and 2006, and the second scenario represented adjustments necessary to fulfill the lake's ecosystem requirements. Under the current water level management practices (Scenario 1), the Strymonas River-Lake Kerkini system has enough water to fulfill its Irrigation Water Requirements (IWR) in normal and wet years while a slight deficit is appeared in dry years; however, both Lake Kerkini and the Strymonas River estuary ecosystems are subject to pressures, since reduction of the forest area has been recorded. Applying the ecosystem approach (Scenario 2), the protection of the riparian forest of Lake Kerkini is achieved while in normal and wet years the IWR are fulfilled and the deficit of the IWR is increased in dry years. Compared to Scenario 1, the pressure of the Strymonas River estuary ecosystem is slightly increased. © 2011 Elsevier Ltd. Source

Discover hidden collaborations