G. Soulios

Contribution à l'étude des courbes de récession des sources karstiques: Exemples du pays Hellénique

Abstract A study of the recession curves of the major springs of some systems of karstic aquifers in Greece shows that each of these aquifers is unique in respect of its boundary conditions, its internal organization and its hydrodynamics, differences which result in different forms of recession curves. These case studies can therefore form the basis for the prediction of the recession curves of karstic springs and hence for the classification of the systems of aquifers.

Comparison of different methods to estimate actual evapotranspiration and hydrologic balance

ABSTRACT The aim of this study was the assessment of the utilization of two methods, i.e. the Thornthwaite and the Turc equations, for the analysis of the water balance in an environmentally sensitive area. The hydrologic balance of a basin consisting in two lakes (Zazari and Cheimaditida) in northern Greece, and covering an area of 228 km2 has been estimated. The Thornthwaite method was applied in the study area, for the calculation of the evapotranspiration factor and was compared to the results obtained by the application of the Turc method in the same area. For the development of these equations and the calculation of the evapotranspiration rates, monthly temperature and precipitation values collected from meteorological stations over a period of 30 years were used. The utilization of monthly average temperatures in the Thornthwaite equation resulted to an actual evapotranspiration rate of ET = 412.7 mm (80.23%) for p = 514.4 mm and a runoff rate of Q = 101.7 mm (19.77%). However, the Turc equation ga...

Support of unstable wedges along the Platamon railway tunnel under construction, in northern Greece

Abstract In this paper, support measures obtained with the RMR classification method were used for estimating the support capacity of wedges found in relatively shallow tunnels. This was done for the Platamon railway tunnel, in northern Greece, which is at present, under construction. According to our investigation, the safety factors, which were calculated using the above mentioned support measures, were much higher than the theoretically needed safety factor. In cases where the height of the wedges is much greater than their base and the rockmass quality is very poor, the proposed RMR support measures could be introduced. In these cases, additional techniques, which include steel ribs and shotcrete (together with rock bolts), could be used.

Water balance of basins in central Greece: Comparison with other circum-Mediterranean basins and validity of empirical methods

The geological and physicogeographical elements of the neighboring basins of Xyniada and Sofaditi in central Greece are given. The average annual and monthly amounts of precipitation that each basin receives for a nineyear period (1972–1981) are estimated by analyzing the data of eight rain gauges. The average annual value of total runoff is also obtained by frequent discharge measurements at the basin outlets during the same period of record, and the water balance of the basins is thus estimated. The examined basins are compared to others in the circum-Mediterranean region. Finally, various empirical methods of estimating components of water balance are applied, and opinions are expressed about the correspondence of these methods to reality and the way they are applied.

Hydrogeological conditions of the upper part of Gallikos river basin

The upper part of Gallikos river watershed basin covers an area of 868.1 km2. The largest part of the basin administratively belongs to the Prefecture of Kilkis. A small part, along the southern border, belongs to the Prefecture of Thessaloniki. The present paper examines the hydrogeological and hydrological conditions of the area. It also describes the geological, lithostratigraphical and tectonic conditions which comprise a determining factor for the quantitative characteristics of surface and groundwater. The recharge and operation mechanism of the aquifers is investigated, as well as their interaction and the role of the surface water. River discharge, water table level, precipitation and water consumption data are presented and the hydrologic balance of the area is calculated.

Piezometric conditions in Pieria basin, Kavala Prefecture, Macedonia, Greece

Pieria basin is located between Paggeon and Symvolon mountains, in Kavala Prefecture. It is characterized by elongated shape with NE-SW direction of development. In the plain area intensive cultivation is applied, which imply to increased water quantities for irrigation. In this paper the piezometry of the study area is analyzed in two periods of measurements according to the lower and the higher water level as well as the correlation between the water level and the irrigation periods. For this reason, systematic water level measurements from March 2005 to November 2007 in regular base were collected from selected boreholes of the basin. Furthermore, data collected in 1996 were also used for comparison.

Décroissance de la perméabilité dans des roches cristallines en fonction de la profondeur d’après des données d’Elassona (Grèce)

RésuméDans la région d’Elassona (Grèce) on a fait 31 forages d’exploration dans des roches cristallines. Des tests d’injection d’eau dans ces forages nous ont permis de calculer la perméabilité K (m/sec) des roches cristallines, tous les 3 m de profondeur. Les valeurs de la permábilité montrent qu’elle décroit avec la profondeur. La décroissance des valeurs moyennes de K en fonction de la profondeur est décrite par une loi exponentielle (à une même profondeur) avec une forte corrélation. Pourtant l’écart-type σ de K est assez fort et le coefficient de variation V est indépendant de la profondeur.AbstractIn crystalline rocks of Elassona area (Greece) 31 exploration drillings were constructed, for engineering purposes. Water injection tests allowed us to calculate the permeability coefficient K (m/sec) for every 3 meters of depth. The permeability values, which were determined, decrease in relation to the depth. The decrease of the mean values of K, in relation to the depth was expressed by an exponential regression, with a correlation of high significance. However the standard deviation σ of K, (at the same depth) is large and the changes of the variation coefficient V are independant of the depth.