Search Results (7)

This study presents the provisional, regulating and cultural ecosystem services that can be delivered by the newly constructed multi-purpose reservoir of Lake Karla located in a water-scarce agricultural area in central Greece. The present short paper takes advantage of literature data and outputs produced from a dynamic GIS hydrologic and management model of the study area with SWAT that simulated hydrology, reservoir operation, irrigation practices and crop production. The paper highlights the net provisional services that the local agricultural society can gain from the full operation of Karla and the additional benefits arising, such as flood control, biodiversity maintenance, aesthetic improvement and touristic opportunities. Full article

Sustainable management is a prerequisite for a lake to provide a range of ecosystem services. The prioritization of needs is a difficult task, especially when the needs are in conflict and threaten water security. Lake Karla, situated in the Thessaly plain, Greece, was decimated in 1957–1962; due to environmental impacts, it was later refilled as a multipurpose reservoir with high ecological significance. The research objective is to achieve a compromise with respect to both the economic benefits derived from agricultural water use and environmental protection based on the minimum intersection. For this purpose, first, new managerial practices are introduced. Second, the ideas are quantified based on the hydrological budget, and these are used as input for flexible (fuzzy) programming. Under hypotheses about the acceptable range, the (flexible) fuzzy programming is identical with the MINMAX goal programming model, although the weights are not used directly in the first case. An understandable compromise (the maximum economic benefit from irrigation areas and the minimization of water retention time) is achieved, and the values of the membership functions can be used to verify the solution. The proposed solution leads to a quantitative proposition, incorporating new findings from modeling the recent real operation of the reservoir. Full article

Cyanobacterial blooms have been known since ancient times; however, they are currently increasing globally. Human and ecological health risks posed by harmful cyanobacterial blooms have been recorded around the world. These risks are mainly associated with their ability to affect the ecosystem chain by different mechanisms like the production of cyanotoxins, especially microcystins. Their expansion and their harmful effects have led many researchers to seek techniques and strategies to control them. Among them, hydrogen peroxide could be a promising tool against cyanobacteria and cyanotoxins and it is well-established as an environmentally friendly oxidizing agent because of its rapid decomposition into oxygen and water. The aim of the present study was to evaluate the effect of hydrogen peroxide on phytoplankton from two hypertrophic waterbodies in Greece. The effect of hydrogen peroxide on concentration of microcystins found in the waterbodies was also studied. Treatment with 4 mg/L hydrogen peroxide was applied to water samples originated from the waterbodies and Cyanobacterial composition and biomass, phycocyanin, chlorophyll-a, and intra-cellular and total microcystin concentrations were studied. Cyanobacterial biomass and phycocyanin was reduced significantly after the application of 4 mg/L hydrogen peroxide in water treatment experiments while chlorophytes and extra-cellular microcystin concentrations were increased. Raphidiopsis (Cylindrospermopsis) raciborskii was the most affected cyanobacterial species after treatment of the water of the Karla Reservoir in comparison to Aphanizomenon favaloroi, Planktolyngbya limnetica, and Chroococcus sp. Furthermore, Microcystis aeruginosa was more resistant to the treatment of Pamvotis lake water in comparison with Microcystis wesenbergii and Microcystis panniformis. Our study showed that hydrogen peroxide differentially impacts the members of the phytoplankton community, affecting, thus, its overall efficacy. Different effects of hydrogen peroxide treatment were observed among cyanobacerial genera as well as among cyanobacterial species of the same genus. Different effects could be the result of the different resistance mechanisms of each genus or species to hydrogen peroxide. Hydrogen peroxide could be used as a treatment for the mitigation of cyanobacterial blooms in a waterbody; however, the biotic and abiotic characteristics of the waterbody should be considered. Full article

This study demonstrates a new nature-based solution (NBS) project in agriculture, the ‘Karla’ reservoir in Central Greece, a unique example at European scale, of a lake ecosystem which was dried and is now restored with the purpose to maximize the efficiency of water provision in agriculture and biodiversity enhancement. In this article, we present: (a) The historical developments from the existence of the old natural Lake Karla until the reconstruction of the homonymous artificial reservoir, (b) the environmental and economic benefits that the new project delivers, and (c) the governance and management mechanisms that can ensure the efficient operation of the project. The analysis shows that the reconstructed Lake Karla can serve as a multi-purpose project to combat water scarcity, achieving a twofold crop yield production and respective agricultural income in the surrounding area, securing the coverage of the water supply needs of the closest city, improving the status of groundwater resources, developing a natural shelter for biodiversity and emerging recreation and touristic opportunities. At the same time, its construction and operation costs can be recovered, and the proposed governance plan can ensure the viability of the whole project inspiring similar multi-purpose water retention projects for investment in agriculture and the environment in southern Europe but also in other water scarce regions. Full article

Lake Karla (Thessaly, Greece) drainage and morphological alterations affected all water-related ecosystem services (ES). The lake is restored as a multipurpose reservoir, whose inflows are boosted with pumping from Pinios River. The Soil and Water Assessment Tool (SWAT) simulated the watershed’s hydrology and the reservoir’s function, under a climate change scenario to assess water related ES. Official timeseries were used for five different scenarios with simulation period until 2100. The results suggest that the reservoir’s water quality is impacted by summer irrigation and by the water volume from the Pinios during winter. As for the selected ES, in almost all scenarios, they seem negatively affected. Full article

The construction of irrigation reservoirs is a technical global solution for enhancing the agricultural production especially in arid and semi-arid areas. These water bodies are treated as technical projects and not as freshwater ecosystems. Eutrophication in new reservoirs becomes a hot issue in the world. The aim of the present study is to present the assessment of the key-eutrophication parameters in seven reservoirs located in the catchment area of Lake Karla. We suggest that the studied artificial ecosystems are sensitive in nutrients concentrations especially in the warm-dry period, influenced mainly by agricultural activities in the watershed. Full article

The paper proposes an integrated modeling system consisting of a surface hydrology model, a water reservoir model, a Lake-Aquifer Interaction model, aground water model, and a transport and dispersion model to study ground water quality through two different operational management scenarios. The first scenario is examining the existing condition of groundwater quality without the reservoir operation while the second scenario is assessing the impact of the reconstruction of Lake Karla in the groundwater quality. The study highlights the importance of using an integrated hydrological modeling approach to investigate the groundwater quality in a region which is characterized by extensive agricultural activity. Full article