Sustainable development in a country with extensive presence of valuable biotopes

Summary The Greek natural environment shows an extensive diversity of flora and fauna and a significantly high density of important biotopes. This notable ecological wealth is threatened with rapid degradation caused by human activities. Its protection through nature conservation measures and through the control of development projects and activities is obstructed by factors such as the existence of a large number of non-point sources of disturbance which are related to a large number of people, the inefficiencies of State mechanisms, the indifference of local societies with regards to planning procedures and long-term social benefits, and a traditionally indifferent or hostile attitude of countryside people towards nature. A study of the threats against the natural environment shows that the most important of these derive from activities that bring people closer to nature, but which follow a development model that is not sustainable. Such activities are: farming, animal grazing, fishing, tourism, vacation house-building, the opening up of roads, hunting, motorized recreation, etc. Contrary to this, the development of industry and the big enterprises of the tertiary sector appears more compatible with the preservation of a rich natural environment when certain conditions such as effective control, use of modern technology and convergence of business and environmental benefits occur. Consequently, this kind of development shows a better perspective as a sustainable development.Kimon Hadjibiros is a physicist-cum-ecologist working at the National Technical University of Athens. This paper, like others in Volume 15, No. 4 ofThe Environmentalist, was presented at the Global Forum '94 Academic Conference Towards a Sustainable Future: Promoting Sustainable Development, Manchester, UK, in June, 1994.     

Concentrations of persistent organic pollutants and organic matter characteristics as river sediment quality indices

Selected persistent organic pollutants – polycyclic aromatic hydrocarbons, polychlorinated biphenyls, and organochlorine pesticides – were determined in sediments, soils, and crops from the Asopos River area, Greece. The river has been receiving industrial effluents for the last 40 years and has been recently found to be polluted with metals. Sediments were collected in the dry (May) and wet (February) season. Agricultural soils and cultivated crops were sampled from adjacent fields. Polychlorinated biphenyls were below the limit of detection in all samples. In one tomato and two soil samples, DDT and DDE were found. Polycyclic aromatic hydrocarbons were observed in 5% of the sediments and in concentrations ranging from 4 to 57 μg kg^?1 dry weight, quite below sediment quality guidelines. Diagnostic ratios of polycyclic aromatic hydrocarbons indicated a strong influence of petrogenic point discharges. In the sediments, silicate minerals dominate over carbonates and the organic carbon content ranges from 0.4% to 3.5%, more than 70% being of natural origin. Compared to other rivers worldwide, the Asopos River was found to be not contaminated with persistent organic pollutants. Point loadings of organic pollutants were evident but continuous discharge is not occurring throughout the river basin.     

Establishing minimum water level for Plastiras reservoir (Greece) combining water quality modelling with landscape aesthetics

A water quality model (MERES) is applied in the multi-purpose reservoir of Plastiras in Greece. The model was calibrated with limited field data using the standard trial and error procedure; next, it was applied for four scenarios of reservoir operation, which correspond to four values of minimum water levels (MWL). Model results were combined with landscape aesthetics to establish a “safe” MWL in the reservoir. MWL was proposed to be +784 m, a value that ensures a very good water quality by retaining the reservoir in the status of “a little beyond oligotrophic” and a very good quality of landscape with an acceptable area of dead zones; it also ensures an annual release of 127.5 hm³ of water within a reliability level of 90%. This quantity can be considered as acceptable from the water supply point of view.     

The growing water imprint of Athens (Greece) throughout history

Throughout its long history from the fifth century B.C. until today, the city of Athens managed to satisfy a gradually increasing urban demand for water supply with reserves obtained by the diversion of freshwater. At first, the water was displaced from the adjacent territories and with time from more distant basins, extending the water imprint of the city on its hinterland. This article traces the history of the development of successive water supply infrastructures, which has resulted in the current situation where Athens controls a significant amount of the water reserves of two (in a total of fourteen) Greek River Basin Districts (Attica and Western Sterea Ellada). With the exception of a short period of drought (1989?C1993), no serious effort has ever been made by the decision makers to slow down the increase of urban per capita consumption in the city. The water imprint of Athens is also linked to the disposal of wastewater in the coastal waters of the Saronic Gulf, since wastewater treatment has been established from 1985 onwards. New lines of thinking are suggested for meeting the needs of the still-growing city of Athens without further increasing its water imprint.     

Effect of ammonoxidation on lignite properties

Oxidised lignite is a potential alternative source of N fertilizers. Ammonoxidation is the reaction of a given substrate with oxygen in aqueous ammonia. Lignite ammonoxidation is used for converting low-rank lignite into slowly nitrogen-releasing artificial humic matter. A lignite sample is compared before and after ammonoxidation in terms of geochemical and petrological properties, as well as the acid–base and physical hydrophobic sorptive behavior. The most obvious change caused by ammonoxidation is the decrease of attrinite, texto-ulminite and textinite in favor mainly of densinite and gelohuminite. In general, the ammonoxidative reactions promote the destruction of the structured humic macerals (texto-ulminite, textinite), and the formation of gels, which resulted in the cementation of the freely fine humic particles (attrinite). The pzc values are 3.4 and 4.3 for oxidised and non-oxidised lignite, respectively. After ammonoxidation the contents of carboxylic and free phenolic groups are found to be lower. The oxidised lignite shows a statistically lower sorptive capacity and affinity than the original sample due to a possible decrease in the hydrophobicity of the lignite.