Anthemountas Basin Research Articles

Tectonic geomorphology and paleoseismology of the Angelochori fault segment of the Anthemountas extensional detachment fault, Central Macedonia, Greece: Paleoseismic evidence from the 1677 CE earthquake

This study presents the results of a geomorphological and paleoseismological investigation on the Angelochori normal fault. This fault controls the southern boundary of the Anthemountas basin and constitutes the western segment of the Anthemountas extensional detachment fault (AEDF), a ∼48 km-long, E-W-trending, north-dipping low-angle normal fault in Central Macedonia, Greece. To assess the relative tectonic activity of the Angelochori fault and to determine the number, timing, and displacement of surface-faulting earthquakes, we conducted detailed field mapping and paleoseismological investigations. Our approach involved utilizing geomorphic indices, analyzing stratigraphic and structural relations, considering luminescence ages, and employing OxCal modeling techniques. The acquired data reveal, for the first time, the Middle-Late Holocene activity of the Anghelochori fault, providing constraints on the age of three strong (M > 6) surface-rupturing earthquakes over the last ∼7.7 ka. The youngest of these events aligns with the historical earthquake of the Anthemountas basin in 1677 CE. The observed minimum displacement per event ranges from 0.48 m to 0.65 m, consistent with a fault length estimated at about 24–28 km, suggesting an earthquake magnitude on the order of 6.6. The cumulative slip rate over the recorded period averages 0.21 ± 0.02 mm/a, with an average open recurrence interval of 2.6 ± 0.2 ka. Nonetheless, the displacement pattern displays alternating intervals of rapid slip at 0.60 ± 0.16 mm/a and slower slip at 0.08 ± 0.01 mm/a. Classified as Class 1, the Angelochori fault signifies an active tectonic structure posing a significant seismic hazard for the Thessaloniki metropolitan area.

A deformation study of Anthemountas graben (northern Greece) based on in situ data and new InSAR results

The focus of this study is Anthemountas basin in northern Greece, where land subsidence phenomena had been previously identified. The basin has a NNW-SSE orientation, which is optimal to the currently acting ~ N-S extension field in the back-arc Aegean area and is bordered to its north and south edge by two, well-pronounced faults. The region of study is located close to the greater metropolitan city of Thessaloniki and comprises a number of critical facilities including the city’s international airport. The research object is the monitoring of the evolution of the displacement at Anthemountas graben, using InSAR time-series and the investigation of the dominant driving mechanism. We show new surface displacement results from the ENVISAR satellite, and overall, an enhanced dataset of SAR time-series is presented, spanning the period 1992 to 2010, by using the satellites ERS1, ERS2 and ENVISAT. Results indicate a continuously deforming environment in both decades, with an increasing magnitude. The detailed study of the deformation pattern together with the analysis of in situ data defines aquifer overpumping as the main cause of the detected displacement of both decades. Critical regions are examined in detail, as for example: an area close to Thermi, the town of Perea and the Thessaloniki’s international airport, a major hub of the Balkans. The latter was subjected to an increasing deforming velocity during the monitoring period. Overall, we conclude that a water management plan should be of high priority for the area.

Origin, implications and management strategies for nitrate pollution in surface and ground waters of Anthemountas basin based on a δ15N-NO3− and δ18O-NO3− isotope approach

Nitrate pollution of surface and groundwater resources is a major worldwide environmental problem. In this study nitrogen isotopes of water, soil, fertilizer and manure were analyzed to determine the pollution sources of nitrate in the groundwater and surface waters of Anthemountas basin. The SIAR model and multivariate statistical analysis were used to determine and quantify the contribution of different NO3̄ sources in groundwater and surface water. Additionally, a detailed literature overview was carried out to identify the origin of nitrate pollution in surface and ground waters based on ΝΟ3− isotopes. The Piper diagram identified the dominant water types as Mg-Ca-HCO3 and Ca-Mg-HCO3. Nitrate concentrations reached 162.0 mg/L in groundwater and 39.0 mg/L in surface waters. The main source of nitrate in groundwater was mainly nitrified ammonium-based synthetic urea and less nitrate-based synthetic fertilizers. The correlation of SIAR results with other trace elements revealed a negative correlation between hexavalent chromium and a) nitrate-based synthetic fertilizers, and b) nitrification of urea synthetic fertilizers. However, a positive correlation was observed between hexavalent chromium and anthropogenic organic matter. The literature overview provided the basis to design a novel management protocol for nitrate pollution that includes three steps: a) fundamental research, b) management tools, c) monitoring and preservation actions. However, an integrated management protocol for nitrate pollution requires a deeper understanding of the hydro-system and the full participation of local farmers and stakeholders.

Delineation of Suitable Zones for the Application of Managed Aquifer Recharge (MAR) in Coastal Aquifers Using Quantitative Parameters and the Analytical Hierarchy Process

Coastal aquifer salinization is usually related to groundwater overexploitation and water table decline. Managed Aquifer Recharge (MAR) can be applied as a measure to reverse and prevent this phenomenon. A detailed literature review was performed to identify the various methods and parameters commonly used to determine suitable sites of MAR application. Based on the review results, a new multi-criteria index (SuSAM) that is compatible to coastal aquifers was developed to delineate suitable zones for MAR application. New parameters were introduced into the index, such as distance from the shore and hydraulic resistance of the vadose zone, while factor weights were determined using the Analytical Hierarchy Process (AHP) and single sensitivity analysis. The applicability of the new index was examined in the coastal aquifer of the Anthemountas basin located in northern Greece. The most suitable areas for MAR application cover 28% of the aquifer’s surface area, while 16% of the area was characterized as non-suitable for MAR application. The new method constitutes the first step of the managed aquifer recharge concept for the delineation of MAR-suitable zones in coastal aquifers.

Predicting bulk density using pedotransfer functions for soils in the Upper Anthemountas basin, Greece

Special equations called Pedotransfer Functions (PTFs) have been broadly implemented as state-of-the-art indirect cost-effective and time-saving methods in predicting soil bulk density (BD). The objectives of the present study are: a) to perform a comprehensive literature review and record published PTFs that estimate BD, b) to evaluate the performance of the recorded PTFs by applying on a soil dataset, built from soil samples collected from a Mediterranean river basin in Northern Greece and c) to further assess this soil dataset in order to develop new functions via multiple forms of regression analysis. In total, 56 PTFs derived from literature were cataloged and evaluated and results display that the function best predicting BD is the one proposed by Rawls (2004). In addition, 13 new PTFs were developed and results reveal that better estimates of BD were obtained when soil texture parameters, contents (%) of Sand (Sa), Silt (Si) and Clay (Cl), were added as predictors. Ultimately, depending on the availability of soil data, two straightforward models: BD = 2.268 − 0.179 ∗ ln(Sa) – 0.345 ∗ ln(OC) or BD = 2.039 − 0.563 ∗ OC + 0.103 ∗ OC2 are proposed for predicting soil BD in the study area.

POTENTIAL TOXIC ELEMENTS (PTES) IN GROUND AND SPRING WATERS, SOILS AND SEDIMENTS: AN INTERDISCIPLINARY STUDY IN ANTHEMOUNTAS BASIN, N. GREECE

Ground and spring waters, soils and sediments of Anthemountas basin in Northern G reece were analyzed for Potential Toxic Elements (PTEs). In total, twenty three soil and sediment samples, three groundwater (boreholes) and two spring water samples, were analyzed. Contents of Ni in soils and sediments can be as high as 2169 mg/kg. The high correlation coefficient of Ni and Cr, indicates the geogenic origin of Ni, which originates from ophiolitic rocks. Arsenic concentration ranges from 3 to 110 mg/kg in soils and sediments, with the highest contents observed in travertine. The spring waters are characterized by elevated concentrations of As (up to 235 μg/L), N a, K, Fe and Zn, indicating that hydrothermal fluids are responsible for feldspar alte ration of the Monopigado granodiorite. On the contrary, in groundwaters, As conten ts are low (up to 18 μg/L). Electrical resistivity tomographies performed around the groundwater boreholes, revealed the presence of normal faults, locally allowing the mixing of geothermal fluids with the shallow porous aquifer (SPA). The presence of As in the SPA is probably due to inputs from geothermal waters through normal faulting.

Hydrogeological regime and groundwater occurence in the Anthemountas River Basin

The Anthemountas river basin is located in northern Greece and covers an area of 374 km2. The mountainous part of the basin consists of ophiolitic, crystalline and carbonate rocks, whereas the lowlands comprise Neogene and Quaternary sediments. Porous aquifers are developed in neogene and quaternary deposits of confined and/or unconfined conditions. Karstic aquifers are developed in the carbonate rocks and there are aquifers in the Mesozoic and Palaeozoic fissured rocks. The water demands of the basin are mainly met by the exploitation of the porous aquifers through a large number of boreholes (more than 1000). The aquifers of fissured rocks discharge through cold springs without significant flow rate. Thermal hot springs are recorded across the Anthemountas fault discharging a mixture of geothermal fluids and cold water from the karst aquifer. According to their hydrogeological and lithological characteristics, porous aquifers can be divided into the subsystems of Galatista and Galarinos in the eastern part of the Anthemountas basin, Vasilika-Risio-Thermi and Tagardes-Trilofos in the western part and Peraia-Agia Triada and AUTh farm-Makedonia airport in the coastal area. For the determination of the aquifers (geometry and anatomy), their recharge mechanisms and hydraulic connection, data from geological maps, lithological profiles, geoelectrical soundings and tomographies, pumping tests and groundwater level measurements are used.

Basin and local scale detection of ground subsidence through persistent scatterer interferometry: The Anthemountas Basin (Northern Greece) case study.

In the framework of the Terrafirma Extension project, a study has been established for ground motion detection and mapping in the Anthemountas basin (Central Macedonia). Terrafirma promotes the exploitation of Persistent Scatterer Interferometry (PSI) techniques, a remote sensing technology based on multi-temporal satellite Synthetic Aperture Radar (SAR) imagery. The potential of SAR interferometry has been exploited through the innovative Wide Area Mapping approach, recently implemented by the German Space Agency (DLR) and aimed at measuring land deformation over large areas. Interferometric results from 1995-2001 by ERS1/2 satellites has been analyzed at a basin scale to investigate spatial patterns of land motion in the wider Anthemountas plain, where subsidence phenomena related to intense groundwater extraction is clearly manifested. The WAP results turned out to be a valuable tool for the characterization at local scale of the land subsidence in the runaways area of the Macedonia airport and in the village of Perea, affected in 2005-2006 by a series of tensile ground ruptures due to excessive groundwater withdrawal. Besides the study of the phenomenon, this work confirmed the suitability of PSI techniques to detect and measure surface displacements with millimetre accuracy and also to reconstruct the deformations history of the investigated areas through displacement time series analysis.

Life cycle assessment of the environmental performance of conventional and organic methods of open field pepper cultivation system

PurposeAs the scale of the organic cultivation sector keeps increasing, there is growing demand for reliable data on organic agriculture and its effect on the environment. Conventional agriculture uses chemical fertilizers and pesticides, whilst organic cultivation mainly relies on crop rotation and organic fertilizers. The aim of this work is to quantify and compare the environmental sustainability of typical conventional and organic pepper cultivation systems.MethodsTwo open field pepper cultivations, both located in the Anthemountas basin, Northern Greece, are selected as case studies. Life cycle assessment (LCA) is used to quantify the overall environmental footprint and identify particular environmental weaknesses (i.e. unsustainable practices) of each cultivation system. Results are analysed at both midpoint and endpoint levels in order to obtain a comprehensive overview of the environmental sustainability of each system. Attributional LCA (ALCA) is employed to identify emissions associated with the life cycles of the two systems. Results are presented for problem-oriented (midpoint) and damage-oriented (endpoint) approaches, using ReCiPe impact assessment.Results and discussionAt midpoint level, conventional cultivation exhibits about threefold higher environmental impact on freshwater eutrophication, than organic cultivation. This arises from the extensive use of nitrogen and phosphorus-based fertilizers, with consequent direct emissions to the environment. The remaining impact categories are mainly affected by irrigation, with associated indirect emissions linked to electricity production. At endpoint level, the main hotspots identified for conventional cultivation are irrigation and fertilizing, due to intensive use of chemical fertilizers and (to a lesser degree) pesticides. For organic pepper cultivation, the main environmental hotspots are irrigation, machinery use, and manure loading and spreading processes. Of these, the highest score for irrigation derives from the heavy electricity consumption required for groundwater pumping associated with the fossil-fuel-dependent Greek electricity mix.ConclusionsOrganic and conventional cultivation systems have similar total environmental impacts per unit of product, with organic cultivation achieving lower environmental impacts in ‘freshwater eutrophication’, ‘climate change’, ‘terrestrial acidification’ and ‘marine eutrophication’ categories. Conventional cultivation has a significantly greater effect on the freshwater eutrophication impact category, due to phosphate emissions arising from application of chemical fertilizers.

Advanced interpretation of interferometric SAR data to detect, monitor and model ground subsidence: outcomes from the ESA-GMES Terrafirma project

Land subsidence is a common natural hazard striking extensive areas worldwide, with severe impacts on economy and environment. Subsidence has been recognized as one of geohazards needing research efforts and knowledge transfer at international level, especially when urban fabrics and infrastructures are directly involved in the land settling. Policies and solutions for land subsidence management can be different. Despite this variability, where mitigation methods need to be adopted, mapping, monitoring and simulation of subsidence have to precede their design and implementation. In this framework, Earth Observation (EO) and remote sensing have a major role to play. Satellite Synthetic Aperture Radar Interferometry, thanks to its wide spatial coverage and its millimeter accuracy, provides a valuable contribution in the management of hazard posed by subsidence-related deformation. The ESA-GMES Terrafirma project (2003–2014) has worked for the promotion of the persistent scatterer interferometry, a family of techniques ideally suited for the assessment of magnitude of surface deformations associated with subsidence phenomena. Within the Terrafirma Project a series of products, based on the integration of EO technologies and in situ data, has been established and delivered to a wide community of end user. Three case studies, outcomes of the Terrafirma project, are presented: the wide area of Rome (Italy), the Anthemountas basin and the Kalochori village (Greece). These case studies have been selected with the purpose of showing the essential contribution of interferometric data during the main activities that must be covered when dealing with geohazard investigations (i.e., mapping, monitoring and modeling). These three case studies are meant to be representative of the suite of services delivered by the Terrafirma project to specific end users with the legal mandated to manage the geohazard.

Groundwater vulnerability and pollution risk assessment with disparate models in karstic, porous, and fissured rock aquifers using remote sensing techniques and GIS in Anthemountas basin, Greece

Disparate methods of intrinsic groundwater vulnerability and remote sensing were applied in Anthemountas river basin (North Greece), covering an area of 374 km2. Three types of aquifers are present within the basin: porous, karstic, and aquifers of fissured rocks. Vulnerability and risk pollution maps were produced using the DRASTIC, EPIK, AVI, and DRASTIC-FM methods in a Geographic information system (GIS) context, and the results were compared and evaluated. The methods used different numbers of parameters with different weightings and produced relatively different results. The original DRASTIC method underestimates the vulnerability degrees in fissured rock aquifers, while in porous aquifers the discretization is poor, in contrast with the AVI method which gives more satisfactory results. The vulnerability of the fissured rock aquifer as estimated by the DRASTIC-FM method shows significant differences compared to the original DRASTIC method. Groundwater pollution risk is strongly dependant on vulnerability, and consequently the use of specialized vulnerability methods provides representative and more accurate results.

Groundwater vulnerability and pollution risk assessment of porous aquifers to nitrate: Modifying the DRASTIC method using quantitative parameters

In the present study the DRASTIC method was modified to estimate vulnerability and pollution risk of porous aquifers to nitrate. The qualitative parameters of aquifer type, soil and impact of the vadose zone were replaced with the quantitative parameters of aquifer thickness, nitrogen losses from soil and hydraulic resistance. Nitrogen losses from soil were estimated based on climatic, soil and topographic data using indices produced by the GLEAMS model. Additionally, the class range of each parameter and the final index were modified using nitrate concentration correlation with four grading methods (natural breaks, equal interval, quantile and geometrical intervals). For this reason, seventy-seven (77) groundwater samples were collected and analyzed for nitrate. Land uses were added to estimate the pollution risk to nitrates. The two new methods, DRASTIC-PA and DRASTIC-PAN, were then applied in the porous aquifer of Anthemountas basin together with the initial versions of DRASTIC and the LOSN-PN index. The two modified methods displayed the highest correlations with nitrate concentrations. The two new methods provided higher discretisation of the vulnerability and pollution risk, whereas the high variance of the (ANOVA) F statistic confirmed the increase of the average concentrations of NO3−, increasing from low to high between the vulnerability and pollution risk classes. The importance of the parameters of hydraulic resistance of the vadose zone, aquifer thickness and land use was confirmed by single-parameter sensitivity analysis.

Advanced interpretation of land subsidence by validating multi-interferometric SAR data: the case study of the Anthemountas basin (Northern Greece)

Abstract. The potential of repeat-pass space borne SAR (Synthetic Aperture Radar) interferometry has been exploited to investigate spatial patterns of land subsidence in the Anthemountas basin, in the northern part of Greece. The PSI (Persistent Scatterer Interferometry) approach, based on the processing of long series of SAR acquisitions, has been applied to forty-two images acquired in 1995–2001 by ERS1/2 satellites. Interferometric results have been analysed at a basin scale as support for land motion mapping and at a local scale for the characterisation of ground motion events affecting the village of Perea in the Thermaikos municipality and the "Macedonia" international airport. PSI results revealed a moderate subsidence phenomenon along the wider coastal zone of Anthemountas basin corresponding to intense groundwater extraction. Highest values, exceeding −20 mm yr−1, were measured in the airport area where the thickest sequence of compressible Quaternary sediments occurs. Intense subsidence has been detected also in the Perea village (maximum deformation of −10 to −15 mm yr−1), where a series of fractures, causing damages to both buildings and infrastructure, occurred in 2005–2006.

Use of simulation models in the protection of groundwater aquifer systems. Application at the Upper Anthemountas basin in Chalkidiki, Greece

The importance of the development and application of groundwater simulation mathematical models in the protection of aquifer systems is nowadays recognised as an undisputable fact. In this paper a mathematical model that was developed in order to simulate the operation of the Upper Anthemountas aquifer in Chalkidiki, Greece, is presented. The case study application investigated concerned the possible malfunction of the Waste Water Treatment Plant located within the study area. According to this scenario a possible malfunction of the treatment plant could pollute the underlying aquifer. A network of observation wells located downstream of the plant could detect the pollution and predict the time needed to reach the productive wells surrounding the area. This allows the local water resources managers to formulate a priori action-plans including, the alteration of the pumping schedule in order to prevent polluted water to be abstracted from the nearby wells and at the same time protect the public health, along with necessary measures concerning the prevention of further pollution and the restoration of the groundwater aquifer system.