Aliakmon River Research Articles

Hydrologic modeling of the Aliakmon River in Greece using HEC–HMS and open data

In recent years, the sharp increase in demand for fresh water and climate change, especially in the Mediterranean region, have increased the need for effective tools that can provide management alternatives enabling the more efficient use of available water resources. Hydrologic models which simulate the rainfall–runoff process are crucial for the formulation of such management tools and can be used to evaluate the performance of systems and, therefore, to formulate alternative management strategies that can lead to more efficient performance. In this paper, an attempt is made to form a hydrologic model with the aim of using it as a basis for the formulation of management tools for the Aliakmon River in Greece. This model could be useful for formulating sustainable production and consumption patterns related to the use of Aliakmon River water. The model is built in HEC–HMS using data that are freely available online. The results indicate that the model shows excellent performance in terms of simulating the changes that occur in the flow regime of the studied river, and can therefore can be used as a basis for the formulation of management tools for the reservoirs present on the river, energy production, water supply, as well as flood forecasting.

Sourcing macrolithics: Mineralogical, geochemical and provenance investigation of stone artefacts from Neolithic Avgi, north‐west Greece

AbstractThe provenance of the lithic raw materials employed in the production of macrolithic artefacts at Neolithic Avgi (Middle–Late Neolithic, c.5700–4500 cal bce) in Kastoria, north‐western Greece, is studied. Mineralogical, petrographic and geochemical analysis was conducted on selected samples of the archaeological material, supported by geological fieldwork and outcrop sampling. The majority of the macrolithic stone artefacts was manufactured by local raw materials, originating from either the neighbouring ophiolites at Maniakoi or the alluvial sediments of the Aliakmon River and its tributaries. A minor amount of artefacts was produced from ‘exotic’ rocks, such as marble, malachite and amber. The study of two marble artefacts indicates that the raw material is from the island of Naxos in Aegean, although the neighbouring island of Paros is not excluded, suggesting the participation of the Neolithic community of Avgi in social and/or exchange networks.

Salmo pelagonicus Karaman, 1938 (Teleostei: Salmonidae), Karamenderes Irmağından Türkiye İçin İlk Kayıt

Salmo pelagonicus Karaman, 1938 was described from Crna River, a tributary of the Vardar River (in Greece). Salmo specimens from the Karamenderes drainage (in Turkey) and Aliakmon River (in Greece), is identified as Salmo pelagonicus. We recorded for the first time Salmo pelagonicus in the Karamenderes River (Aegean Sea basin) in Turkey. It was compared with Salmo species in adjacent waters. Our comparison show that the Karamenderes population differs from other species in neighboring basins. Also in this study, it was given detailed morphological characters of Salmo pelagonicus.

Birth and closure of the Kallipetra Basin: Late Cretaceous reworking of the Jurassic Pelagonian–Axios/Vardar contact (northern Greece)

Abstract. Some 20 Myr after the Late Jurassic to Early Cretaceous obduction and collision at the eastern margin of Adria, the eroded Pelagonia (Adria)–Axios/Vardar (oceanic complex) contact collapsed, forming the Kallipetra Basin, described around the Aliakmon River near Veroia (northern Greece). Clastic and carbonate marine sediments deposited from the early Cenomanian to the end of the Turonian, with abundant olistoliths and slope failures at the base due to active normal faults. The middle part of the series is characterized by red and green pelagic limestones, with a minimal contribution of terrigenous debris. Rudist mounds in the upper part of the basin started forming on the southwestern slope, and their growth competed with a flux of ophiolitic debris, documenting the new fault scarps affecting the Vardar oceanic complex (VOC). Eventually, the basin was closed by overthrusting of the VOC towards the northeast and was buried and heated up to ∼ 180 ∘C. A strong reverse geothermal gradient with temperatures increasing up-section to near 300 ∘C is recorded beneath the VOC by illite crystallinity and by the crystallization of chlorite during deformation. This syntectonic heat partially reset the zircon fission track ages bracketing the timing of closure just after the deposition of the ophiolitic debris in the Turonian. This study documents the reworking of the Pelagonian–Axios/Vardar contact, with Cenomanian extension and basin widening followed by Turonian compression and basin inversion. Thrusting occurred earlier than previously reported in the literature for the eastern Adria and shows a vergence toward the northeast, at odds with the regional southwest vergence of the whole margin but in accordance to some reports about 50 km north.

Optimizing Current and Future Hydroelectric Energy Production and Water Uses of the Complex Multi-Reservoir System in the Aliakmon River, Greece

In this work we study long-term maximization of hydroelectric energy generation from complex multi-purpose reservoir systems, using the reservoir system of the Aliakmon River, Greece, as an application example. This system serves various purposes, like urban water supply, irrigation, hydroelectric energy production, cooling thermoelectric power plants and flood control, while preserving environmental flow. The system operator uses institutional rules for the annual scheduling of the outflows of the 2 largest reservoirs (Ilarion and Polyfyto) for additional safety and smooth distribution of energy production through the year. In this work, we focus on maximization of energy production. We have considered three different hydrological scenarios (dry, average and wet), both for the current and for anticipated future water demand. The multi-reservoir system’s operation was simulated and then optimized using a rather simple form of genetic algorithms, in order to maximize hydro energy production. All other water uses were taken into account as constraints. Our conceptual and computational approach succeeded to identify and quantify hydro energy production increase and to indicate necessary changes to the operating rule curves of the reservoirs. The methodology can be easily adapted to other large-scale multi reservoir systems.

Comparative water quality assessment between a young and a stabilized hydroelectric reservoir in Aliakmon River, Greece

In this work, a comparative study on the water quality characteristics of two in-line water reservoirs (artificial lakes) in Aliakmon River (Western Macedonia, Greece) is performed. Polyfytos Reservoir and Ilarion Reservoir were created in 1975 and 2012 respectively, in order to serve the homonymous hydroelectric stations. In young artificial lakes, severe deterioration of water quality may occur; thus, the monitoring and assessment of their water quality characteristics and their statistical interpretation are of great importance. In order to evaluate any temporal or spatial variations and to characterize water quality of these two in-line water reservoirs, water quality data from measurements conducted from 2012 to 2015 were statistically processed and interpreted by using a modified National Sanitation Foundation water quality index (WQI). The water physicochemical characteristics of the two reservoirs were found to be generally within the legislation limits, with relatively small temporal and spatial variations. Although Polyfytos Reservoir showed no significant deviations of its water quality, Ilarion Reservoir exhibited deviations in total Kjeldahl nitrogen, nitrite nitrogen, total suspended solids, and turbidity due to the inundated vegetation decomposition. The conducted measurements and the use of the modified NSFWQI revealed that during the inundation period of Ilarion Reservoir, its water quality was "moderate" and that the deviations were softened through time, leading to "good" water quality during its maturation period. Three years since the creation of Ilarion Reservoir, water quality does not match that of Aliakmon River (feeding water) or that of the stabilized reservoir (Polyfytos Reservoir), whose quality is characterized as "high." The use of a WQI, such as the proposed modified NSFWQI, for evaluating water quality of each sampling site and of an entire water system proved to be a rapid and relatively accurate assessment tool.

PRESERVING THE NON-PRESERVABLE GEOHERITAGE OF THE ALIAKMON RIVER: A CASE STUDY IN GEOEDUCATION LEADING TO CUTTING-EDGE SCIENCE

The initial documentation of an ophiolite as oceanic lithosphere and the significance of an ophiolite’s basal sole in its emplacement were based on the research of E. Moores (1969) and J. Zimmerman (1968) at the Vourinos Ophiolite, Greece: their work became a lynch-pin in the establishment of plate tectonic theory. Key localities of their research were located along the Aliakmon River Valley between Ilariona Monastery and the village of Panayia. This same area has since been flooded (2012) with the construction of a new hydroelectric reservoir. There was no option for “saving” these sites of the birth of plate tectonic theory: what could be done to preserve their geoheritage? Between 2005 and 2008, the Institute of Geology and Mineral Exploration, with funding provided from the Public Power Corporation, sponsored geo-education to provide a “last chance” of geologic documentation of the Aliakmon Valley. In a three year period, over 60 international student and professorial-level researchers participated in the project. 37 Senior Theses were produced and 6 masters’ dissertations. The greatest achievement of the program was the revitalization of the Aliakmon data base within current, cutting-edge scientific models.

Early- to mid-Holocene paleohydrology in northeast Mediterranean: The detrital record of Aliakmon River in Loudias Lake, Greece

One of the prominent features of northeast Mediterranean (NEM) Holocene climate are recurrent phases of cold and aridity; their impacts on the hydrological cycle remain at large unknown, as few existing paleohydrological records are either restricted to lake-level fluctuations or focus near the ‘8.2 kyr BP’ event. Here, we present the detrital record of Aliakmon River in Lake Loudias between 9500 and 3000 cal. BP. Magnetic susceptibility (MS) exhibits high correlation with mean grain size ( r = 0.7) of silt-sized fractions and is used as a proxy of the distal clastic input of Aliakmon River, whereas organic matter (OM), carbonate content (CaCO3), water content (WC), and clay concentrations decipher sedimentological and biological processes in Lake Loudias. Periods of high hydrological activity were interrupted by short intervals of low river discharge at c. 9400, 8600, 8200, 7500, 7000, 6200, 5300, and 4500 cal. BP and during a multi-century event centered at 3500 cal. BP, in agreement with marine and terrestrial paleoclimatic reconstructions from NEM. With exception of the wet period between c. 8.6 and 7.9 cal. BP, periods of increased hydrological activity are synchronous to contraction of Pinus forests and increased sea surface temperatures and silt transport in the Aegean Sea. The long-term (~580 years) variability of MS is in-phase with southeast Europe pollen-inferred annual temperature variations and with North Atlantic Ice Rafted Debris (IRD) events.

The Late Pliocene Bovidae and Cervidae (Mammalia) of Milia (Grevena, Macedonia, Greece)

Since 1996 Late Pliocene ruminants have been excavated from sand deposits exposed along the Aliakmon River valley at Milia (Grevena, Western Macedonia, Greece). The Bovidae include five species: the new large Bovini Grevenobos antiquus, Alephis sp., Bovini indet., Gazella borbonica, and Antilopinae indet., Cervidae are less common and include Croizetoceros ramosus, Praeelaphus cf. lyra and Cervidae indet. The association of Alephis sp., G. borbonica, Cr. ramosus, Homotherium sp., Agriotherium sp., Mammut borsoni, Anancus arvernensis, Tapirus arvernensis arvernensis, Stephanorhinus jeanvireti, Hipparion sp. (H. crassum group) and Sus arvernensis arvernensis allows us to date this faunal assemblage to the transition between MN 15 and MN 16a. It is the first time that such transitional assemblage is documented in Europe.

KASTORIA “BLIND” ACTIVE FAULT: HAZARDOUS SEISMOGENIC FAULT OF THE NW GREECE

The Aliakmon river bed, as well as a series of certain parallel narrow grabens, striking NW-SE are filled with Neogene-Quaternary deposits; thus showing the existence of the covered, “blind”, fault zone, which borders the Eastern edge of Meso-Hellenic Trench and passes in close vicinity to the Kastoria town. Distribution of earthquakes epicentres (M≥4.0, for the period of 1930-2009) along this segmented rupture zone, proves the existence at depth of an active seismogenic fault which has generated some strong earthquakes in the past: 1709, M = 6.0; 1812, M = 6.5 and 1894, M = 6.1 (~ 100-year Recurrence Time events). The calculations of Lapsed Rate characterizing the stage of the fault seismic cycle (LR = 115%) show that the active Kastoria fault could be in a pre-seismic stage of its seismic cycle. Applying the seismicity rates model (time-independent Gutenberg-Richter recurrence model) and using the fault seismicity parameters, obtained inside the fault influence zone, as input in EZ-FRISK® software, the Probabilistic Seismic Hazard Analysis has been carried out for the area of Kastoria town. The results show that calculated magnitude for event with 100- year recurrence time is ~6.1, which correspond to the magnitude of three events, occurred at the fault during the last 300 years (corresponding average slip rate . 3 mm/year). As the calculated Hazard Curve shows, the event of that range could give ground shaking in the Kastoria town in the order of 0.625 g at the spectral period of 0.3 sec.

Variability analysis of hydrometeorological parameters under a climate change scenario in Northern Greece

In this work an attempt is undertaken to analyse the impacts of climate change in crucial hydrometeorological parameters affecting the agriculture production yield. As study area, the Siatista sub-basin of Aliakmon river was selected, located in Northern Greece. More particularly the regional hydrological cycle was evaluated on river basin spatial scale to assess regional impacts and variability. A monthly conceptual water balance model was calibrated, using historical hydrometeorological data covering a 30-year period. This model was applied to estimate runoff values at the outlet of the sub-basin incorporating the output data of a climate change scenario. The selected climate change scenario is United Kingdom Transient Run (UKTR) which is a transient scenario, referring to year 2080. The results show that the mean annual runoff, mean winter, as well as mean summer runoff values, will be reduced. The reduction ranges from 15% to 65%. The actual evapotranspiration in the winter months will increase (the range is from 6 to 800%), while the opposite occurs in the summer months (the range is from 38 to 69%) due to reduced runoff.

The Proboscidea of the Early Villafranchian site of Milia (Grevena, Macedonia, Greece)

Two different species of Early Villafranchian proboscideans were contemporaneous in Milia (Grevena, Western Macedonia, Greece): the large zygodont, Borson's mastodon, Mammut borsoni (Hays, 1834), and the smaller gomphothere, the mastodon of Auvergne, Anancus arvernensis (Croizet et Jobert, 1828), the former being predominant. Since 1996 partial skeletons and a large number of isolated skeletal elements of the zygodonts have been excavated from Aliakmon River sand deposits in Milia. The skeletons include substantial portions of the cranium with left and right molars (M2, M3); two complete pairs of the longest upper tusks ever recorded in the world (4.39 m and 5.02 m) and the most complete mandible in Europe, with the two entire lower tusks in anatomical position, as well as two almost-complete mandibles with dentition (m2 + m3); and post-cranials. These partial skeletons represent very robust male individuals in the prime of their life at time of death. In this paper, we describe a new partial skeleton and we discuss the evolutionary position of the specimens among mammutids, the stratigraphy and the paleoenvironment. The enriched Milia zygodont material is compared with other European specimens in order to get a better understanding of its extinction.

Late Pleistocene to Mid-Holocene landscape reconstruction in the western part of the Thessaloniki Plain, Greece: evidence for environmental changes, and implications for human occupation

This study presents new data from four boreholes in order to investigate the palaeoenvironmental changes and landscape configuration from the Late Pleistocene to the Mid-Holocene in the western part of the Thessaloniki plain. Palaeoenvironmental and archaeological records from northern Greece document the occurrence of significant landscape changes during the Holocene. While traces of human occupation are scarce in the western Thessaloniki plain during the transition from the Late Pleistocene (Lateglacial) to the Holocene (Mesolithic period), the climatic and environmental changes involved significant and abrupt impacts on surface processes. Recently published results indicated that palaeoenvironmental transitions in the area influenced the human occupation from the early Holocene (8000/7800 cal. BP) to recent times. However, the Late Pleistocene landscape configuration has not been clearly established. A new sequence is used for analyses of grain size, loss-on-ignition, carbonate content and rock magnetic properties. In addition, a series of 6 new AMS dates from the area provide a precise chronostratigraphy. The synthesis of the environmental proxies reveals distinct palaeoenvironmental changes within a well-constructed chronostratigraphic framework of more than 10k years, which is the longest sedimentary sequence reported for central Macedonia. The Late Pleistocene subsurface occurs at ~9 m depth and clearly indicates the presence of a large alluvial fan deposited by the Aliakmon River during the Younger Dryas (12.7k-11.7kyr BP). The abrupt transition to Early Holocene sediments reveals that a significant influx of fresh water generated a limnic sedimentary environment under detrital and human stress, from pre- to post-reforestation period in the area. Anthropogenic influence is also significantly recorded mainly by the magnetic properties of the lacustrine sediments after 9000 cal. BP. From Neolithic times to the present day, the study area was periodically occupied by a freshwater lake while palaeo-soils are clearly identified by anthropogenic activities and are dated from the Early Neolithic period.

A simple approach to define Holocene sequence stratigraphy using borehole and cone penetration test data

AbstractCone penetration testing has been widely used since the 1950s for determining the subsurface geotechnical conditions of unconsolidated sediments. This paper highlights the potential value of cone penetration testing as an aid to define the stratigraphic structure of Holocene sedimentary deposits. By calibrating cone penetration test logs with adjacent borehole logs and by utilizing all the available information produced during geotechnical surveying, stratigraphic models that accurately describe the vertical and lateral boundaries, as well as the stacking pattern, of Late Quaternary systems can be constructed. The widespread application and technical simplicity of cone penetration testing, combined with simple data interpretation via correlation with adjacent borehole logs, yield a useful and inexpensive tool for sedimentological investigations. This methodology is illustrated using data from 36 cone penetration tests and 11 boreholes on the Holocene deltaic plain of the Aliakmon River, Greece. Sedimentological and stratigraphic information from core log correlations, the spatial distribution of cone penetration test parameters, sediment grain size and per cent concentration of organic matter are utilized. The results suggest, that in sequence stratigraphic terms, the delta is divided into a lowstand systems tract composed by fluvial gravels and sands (U0) of Late Pleistocene age, as well as from red oxidized clays, and a transgressive systems tract represented by fluvial channel sands (U1), overlain by a thin transgressive sand sheet of coastal origin (U2), characterized by fining upward trends. The highstand systems tract is constituted by a variety of stratigraphic units (U3 to U7) and depositional environments, characterized by coarsening upward sequences, representing both aggradational and progradational facies, and dominated by the presence of three prograding wedges. Detailed definition of the thickness, vertical boundaries and stacking pattern of the resolved stratigraphic units, presented as a two‐dimensional stratigraphic model, demonstrates the applicability of the proposed method.

Stabilization of the limestone escarpment of the Skete of Osios Nikanoras under wet conditions due to future filling of the Ilarion dam's reservoir.

The Skete of Osios Nikanoras is located in a cavern of a vertical limestone escarpment 80m high, over Aliakmon River in West Macedonia. The vertical slope is structured predominantly of thick-bedded limestone, dipping moderately towards NW and only locally of thin-bedded limestone. It is crossed by three transverse and four normal faults. Rock mass was divided in sections, demarcated by bedding planes and major discontinuities. Each section was subdivided into rock blocks. Rock mass description was carried out in areas below the entrance level and the surrounding areas of the Skete as well. The future water level rise, due to the filling of the Ilarion Dam’s reservoir, followed by water level fluctuations, will impose an initial increase and a subsequent variation of water pressures in the rock mass discontinuities. The evaluation of the rock mass stability, due to water induced loads, was therefore required. Stability analysis has been performed in order to determine potential wedge, plane and toppling failure modes. The measures that were adopted for the conservation of the monument were designed taking into account the restrictions regarding the monuments preservation. The proposed solution comprised three stages of installation of support measures, namely, installation of temporary rock bolts for the pre-strengthening of the rock mass, followed by the execution of grouting and finally installation of permanent rock anchors, thus ensuring adequate factors of safety.

Sustainable water resources management through the use of GIS technology

The increasing water demand, the prolonged drought periods and the human influence in natural resources that put in danger the quantity and quality of water resources, highlight the importance for rational management and exploitation of water resources in terms of sustainable development of an area. The purpose of this study is the application of procedures for sustainable management and development of the water resources of the Grevenitis basin, using Geographic Information Systems (GIS) technology. Grevenitis drainage basin is part of the greater Aliakmon river drainage basin (NW Greece). It’s located in the central section of Mesohellenic Trough. The study reveals the capability of itself-reliance of the area of Grevenitis basin in covering the total water needs and the new perspectives for sustainable development of the area with the exploitation of the surface waters of Grevenitis river and the groundwater of the aquifer formed in the Plio-Pleistocene sediments, which overlay on the impermeable molassic sediments. It’s also shown the important contribution of GIS technology with the creation of databases for the continuous monitoring of the various parameters with their changes and the convenience for direct drawing of thematic maps. The evaluation of quality parameters of drinking water brings to light useful results and recommendations in order to assist and improve current water quality monitoring and protective actions.

Hydrochemical and Ecological Quality Assessment of a Mediterranean River System

In order to explore the complex interrelations among the factors and processes that determine a rivers’ hydrochemical and biological quality, statistical techniques were applied to a variety of hydrochemical, petrologic, biological, habitat, hydrological and morphologic data from 16 sites of the upper-part of the Aliakmon river. Catchment morphology and geology control both, aquatic and biological quality, the latter is mainly governed by substrate composition. The principal processes that control aquatic quality are: a) baseflow contribution in river flow b) in-stream biological activity and pollution c) weathering of mafic silicates. Using a Nutrient Pollution Metric (which has been developed), a hydrochemical quality classification has been performed. Furthermore, a methodology, based on benthic macroinvertebrates and aquatic quality, for the assessment of the ecological quality of running waters is presented.

Reconstruction of the landscape history around the remnant arch of the Klidhi Roman Bridge, Thessaloniki Plain, North Central Greece

This paper deals with the palaeoenvironmental reconstruction of the area surrounding the remnant arch of the ancient bridge of Klidhi, Thessaloniki Plain, Greece. 19th century travellers and 20th century historians discussed the age of the monument and concluded that it was built during Late Roman Times (3rd Cent. AD) and supported a branch of the Via Egnatia road. However, few studies have considered the environmental context of the construction of the bridge, and until now, only two hypotheses have been presented: The bridge was built on or over a junction of the Aliakmon and Loudias Rivers, or on a coastal barrier. Within the framework of a geoarchaeological project developed in April 2008, five boreholes were drilled and the sediment cores analysed for microfauna and sedimentology. Seven 14C AMS dates provided a chronostratigraphic sequence and helped to define the geomorphological evolution of the area. Spatial interpretation of the results was possible using a Landsat TM image (False Colour Composite – FCC). Our data indicate the gradual transition of the site from a marine to a terrestrial environment during Ancient Times. Lagoonal conditions dominated during the construction of the bridge and the presence of a palaeochannel of the Aliakmon River was later revealed (transition from Byzantine and Ottoman periods), overlying sediments of a coastal barrier.

Climate Change and Associated Implications for the Water Policy Framework in the Basin of Venetikos

The impact of climate change on the hydrological regime and water resources in the basin of Venetikos has been assessed in this paper. Venetikos is a sub-basin of the Aliakmon River Basin, located in northern Greece. A monthly conceptual water balance model was calibrated using historical hydrometeorological data to determine changes in stream-flow runoff under two different equilibrium scenarios (UKHI, CCC) for year 2020, 2050 and 2100. The application of the two scenarios resulted in reduction of the mean winter and summer runoff values, and increase in maximum annual and decrease in minimum annual runoff values. Additionally, an increase of potential and actual evapo-transpiration was noticed due to temperature increase. As a result, a reduction of snow accumulation, as well as a decrease in spring runoff values and soil moisture are expected. A shift of the wet period towards December is remarked, resulting in severe prolongation of the dry period. Consequently, the water policy should be revised in order to address the above possible future changes.

Environmental Parameters Affecting the Species Diversity Along the Aliakmon River, North Greece

The annual distribution of aquatic and coastal macrophytes in five selected sites along the Aliakmon River was studied from January 2005 to December 2005 in Northern Greece. Soil and water chemical parameters in these sites were also evaluated. A total of 75 taxa were recorded belonging to 37 families and 53 genera. The majority of the macrophytes belonged to coastal plants (76%), whereas the rest of the macrophytes belonged to aquatic plants (24%). Species of the family Asteraceae were dominant among coastal plants, whereas species of the family Potamogetonaceae were dominant among aquatic plants. Soil samples from the site of Dam of Veria had higher pH and electric conductivity (80-100 cm depth), whereas CaCO3 contents were significantly higher in soil samples from the area of P. Prodromos (60-80 cm depth). Most physicochemical water parameters as well as selected soil nutrients and major ionic components showed an increase during the low charge period (fall) compared to with the high charge period (spring), especially in parameters associated with agricultural activity. Furthermore, there was an increase in most examined values moving towards the delta of the river.