Pinios River Research Articles

Groundwater level response to precipitation at the hydrological observatory of Pinios (central Greece)

To study groundwater dynamics and their response to precipitation in the Pinios river basin (central Greece), the variation trends and seasonal patterns of fourteen monitored groundwater and two precipitation time series were examined using time series decomposition, autocorrelation, and wavelet analysis. The objective is to perform indirect methodologies based on groundwater level and precipitation data to attain a detailed understanding of the hydrogeological mechanisms of the aquifer system and develop an approach that can be easily employed worldwide. The three approaches confirm local groundwater circulation understanding by dividing the aquifer system into three parts characterised by varying transmissivity and storativity properties. The extended memory effect, ranging between 70 and 230 days suggests great inertia and storage capacity of the examined groundwater system. The wavelet analysis proves that the system acts as a filter which absorbs the precipitation frequencies converting them into GWL signals, as demonstrated by the 256 days periodicity shared by groundwater level and precipitation time series. Generally, GWLs present a hysteresis to precipitation due to the geological setup and local flow conditions and are particularly affected by a seasonal component, as also highlighted by time series decomposition. An evident annual periodicity is also observed in hydrological and hydrogeological time series. Results suggest the effectiveness of the proposed combination of methods in developing hydrological understanding and their general applicability to other regions where at least groundwater level and precipitation time series are available. By utilising such data-driven approaches, hydrogeologists and water resource managers can gain valuable insights into the behavior of aquifers, groundwater flow patterns, and the impact of human activities on groundwater quality and quantity.

A Participatory Approach to Exploring Nexus Challenges: A Case Study on the Pinios River Basin, Greece

The conservation of natural resources is indispensable for supporting sustainable development. Water–Energy–Food–Ecosystem (WEFE) nexus management is widely acknowledged as the utmost priority of our time. Considering the specificities of the different nexus sectors, conflicting views of sustainability may arise from different stakeholders. This paper presents and analyses an effective stakeholders’ participation strategy aiming at identifying WEFE challenges in the Pinios River Basin (PRB), the most agriculturally productive and natural resource-stressed basin of Greece. The presented methodology was developed in the context of a Learning and Action Alliance (LAA) scheme adopted by the H2020 REXUS project, intended to support resilient nexus system management with the engagement of stakeholders. The proposed comprehensive methodology comprises multiple phases, including “framing”, “mapping”, “involvement”, “co-production”, and “sharing” phases. The involvement phase is the most interactive one, including the organisation and outputs of efficient crowdsourcing theme sessions organised in the framework of the first REXUS PRB stakeholders’ workshop. This paper illustrates and analyses stakeholders’ perceptions regarding nexus status in the PRB and reveals the most critical challenges in the pilot basin, along with their interdependencies and correlations. The determination of nexus challenges insights by stakeholders could significantly contribute to redefining policies so that they align with sustainable development aims. This methodology is proposed to form the baseline strategy in stakeholders’ engagement for future nexus management studies.

Stable isotopes reveal organic nitrogen pollution and cycling from point and non-point sources in a heavily cultivated (agricultural) Mediterranean river basin

The Pinios River Basin (PRB) is the most intensively cultivated area in Greece, which hosts numerous industries and other anthropogenic activities. The analysis of water samples collected monthly for ∼1 ½ years in eight monitoring sites in the PRB revealed nitrate pollution of organic origin extending from upstream to downstream and occurring throughout the year, masking the signal from the application of synthetic fertilizers. Nitrate concentrations reached up to 3.6 mg/l as NO3−-N, without exceeding the drinking water threshold of ∼11.0 mg/l (as NO3−-N). However, the water quality status was “poor” or “bad” in ∼50 % of the samples based on a local index, which considers the potential impact of nitrate on aquatic biological communities. The δ15Ν-ΝΟ3− and δ18O-NO3− values ranged from +4.4 ‰ to +20.3 ‰ and from −0.5 ‰ to +14.4 ‰, respectively. The application of a Bayesian model showed that the proportional contribution of organic pollution from industries, animal breeding facilities and manure fertilizers exceeded 70 % in most river sites with an overall uncertainty of ∼0.3 (UI90 index). The δ18O-NO3− and its relationship with δ18O-H2O revealed N-cycling and mixing processes, which were difficult to identify apart from the uptake of nutrients by phytoplankton during the growing season and metabolic activities. The strong correlation of δ15Ν-ΝΟ3− values with a Land Use Index (LUI) and a Point Source Index (PSI) highlighted not only the role of non-point nitrate sources but also of point sources of nitrate pollution on water quality degradation, which are usually overlooked. The nitrification of organic wastes is the dominant nitrate source in most rivers in Europe. The systematic monitoring of rivers for nitrate isotopes will help improve the understanding of N-cycling and the impact of these pollutants on ecosystems and better inform policies for protection measures so to achieve good ecological status.

Insights into the influence of morphology on the hydrological processes of river catchments using stable isotopes

ABSTRACT Water isotopes (δ18O, δ2H) were systematically monitored in two river catchments to investigate the isotopic spatiotemporal variation and the differences between them. The Pinios River Basin (PRB) exhibited lower average δ 18O and δ 2H values (−7.9‰ and −50.8‰, respectively) compared to the Evrotas River Basin (ERB) (−6.5‰ and −38.2‰, respectively) but higher in range (3.3‰ vs 1.2‰ for δ18O, respectively). The Bayesian modelling results showed higher groundwater contribution in the PRB (25–50%) than in the ERB (15–35%) relative to precipitation during the wet period. The isotopic spatial variability was attributed to the influence of local precipitation, evaporation and additional flow pathways (e.g. soil water). The correlation analysis showed that the isotopic composition is controlled by the catchment altitude, slope and discharge. This study highlights the catchment physiographic control on the isotopic composition of rivers, which can support strategies for better water resources management.

Fully Distributed Water Balance Modelling in Large Agricultural Areas—The Pinios River Basin (Greece) Case Study

Robust assessments of variations in freshwater availability are essential for current and future water resource management in the Pinios River Basin (PRB), which is one of the most productive basins of Greece in terms of agriculture. To support sustainable water resources management in the PRB, we set up and calibrated the mGROWA hydrological model at a high spatial (100 m) and temporal (daily) resolution for the period 1971–2000, with particular attention given to deriving crop-specific irrigation requirements. We developed and implemented a comprehensive methodological framework to overcome data scarcity constraints in the PRB, thus enabling the derivation of high-resolution spatially continuous estimates of many input variables required for the mGROWA model. We generated estimates of spatiotemporal variations in the water balance components actual evapotranspiration, irrigation requirements, total runoff, and groundwater recharge for the PRB. In addition, through the calculation of indices, such as the potential irrigation to groundwater recharge ratio (PIQR), we demonstrate a way to identify potential unsustainable water use in irrigated agriculture. The established mGROWA model can be used both as a hydrological reference model providing continuous decision support for water resources management, focusing on irrigation water use, and a basis for climate impact studies for the PRB.

Floodplain evolution and its influence on liquefaction clustering: The case study of March 2021 Thessaly, Greece, seismic sequence

The March 2021 Thessaly, Central Greece, seismic sequence characterized by an Mw = 6.3 mainshock and five Mw > 5.0 aftershocks triggered extensive liquefaction in the floodplain of the Piniada Valley and localized phenomena along the riverbanks of the Titarissios River. In order to document these secondary effects, we carried out immediate post event surveys based on remote sensing techniques and field-based reconnaissance. The initial desktop-based approach succeeded in delineating in advance the extensive liquefaction surface manifestations and in saving time for the subsequent field survey. The field work was performed with ground-based surveys, and UAV aerial campaigns. The longest reported linear liquefaction feature was 26.7 m, while the total sand blow covered an area of 0.0325 km2. Over one of the liquefaction manifestations, we performed parallel 2D electrical resistivity tomography profiles in order to reconstruct the subsoil stratigraphy. The produced 3D resistivity model successfully detects and illustrates the subsurface disruption following the generation of liquefaction. From the comparison between the spatial distribution of liquefaction phenomena and the geomorphological conditions in the area, the direct influence of the historical evolution of Pinios River in clustering liquefaction phenomena was highlighted. Thus, it is confirmed that a detailed investigation of the historical and late Holocene evolution of a floodplain i.e., location of ox-bow lakes, meanders and former river channels, can identify sites prone to liquefaction. This could result in a reduction of the area where detailed engineering geology investigations (e.g., boreholes with in-situ tests) are required for the evaluation of the liquefaction hazard.

A Flood Inundation Modeling Approach for Urban and Rural Areas in Lake and Large-Scale River Basins

Fluvial floods are one of the primary natural hazards to our society, and the associated flood risk should always be evaluated for present and future conditions. The European Union’s (EU) Floods Directive highlights the importance of flood mapping as a key stage for detecting vulnerable areas, assessing floods’ impacts, and identifying damages and compensation plans. The implementation of the EU Flood Directive in Greece is challenging because of its geophysical and climatic variability and diverse hydrologic and hydraulic conditions. This study addressed this challenge by modeling of design rainfall at the sub-watershed level and subsequent estimation of flood design hydrographs using the Natural Resources Conservation Service (NRCS) Unit Hydrograph Procedure. The HEC-RAS 2D model was used for flood routing, estimation of flood attributes (i.e., water depths and flow velocities), and mapping of inundated areas. The modeling approach was applied at two complex and ungauged representative basins: The Lake Pamvotida basin located in the Epirus Region of the wet Western Greece, and the Pinios River basin located in the Thessaly Region of the drier Central Greece, a basin with a complex dendritic hydrographic system, expanding to more than 1188 river-km. The proposed modeling approach aimed at better estimation and mapping of flood inundation areas including relative uncertainties and providing guidance to professionals and academics.

Late Quaternary hydrographic evolution in Thessaly (Central Greece): The crucial role of the Piniada Valley

The present-day hydrographic network of the Pinios River, Greece, clearly shows some major morphological and hydrographic anomalies documenting its complex evolution. A critical analysis and re-interpretation of geological and historical/modern topographic data clearly indicate an original subdivision of Thessaly into two separate endorheic hydrographic networks, Karditsa and Larissa realms. At different epochs, these two basins were partially covered by lake waters and/or marsh areas up to late Antiquity and locally/temporarily even in recent historical periods. The Piniada Valley is in between the two major (present-day) alluvial plains existing in Thessaly. The pre-infilling morphology of the valley bottom has been recently reconstructed suggesting it likely represented the lower reach of the Titarissios River draining into the Karditsa basin. These environmental-depositional conditions persisted up to Late Pleistocene when tectonic activity along the Tyrnavos and Larissa faults diverted the lower reach of this river into the Larissa area causing the abandonment of the Piniada Valley. Depending on the water discharge along the western Thessalian rivers and the consequent water level fluctuations of the Karditsa Lake, together with the gradual infilling of the basin, the Piniada Valley and especially its western sector was then largely affected by lacustrine-to-marshy conditions. This was also due to the lacking of a permanent hydrographic network draining the area. Indeed, the present-day Pinios River could form only after the prograding 'western' rivers completely infilled the Karditsa basin by generating a hydrographic network in the plain. Only in the latest stage of this process, the Piniada Valley was characterized by fluvial aggradation, causing the alluvial plain to expand eastwards finally reaching the altimetric threshold of the Kalamaki Gorge. This last phenomenon definitely established a permanent hydrographic connection between western and eastern Thessaly.

Investigating the Effects of Agricultural Water Management in a Mediterranean Coastal Aquifer under Current and Projected Climate Conditions

Coastal delta plains are areas with high agricultural potential for the Mediterranean region because of their high soil fertility, but they also constitute fragile systems in terms of water resources management because of the interaction of underlying aquifers with the sea. Such a case is the Pinios River delta plain located in central Greece, which also constitutes a significant ecosystem. Soil and Water Assessment Tool (SWAT) and SEAWAT models were combined in order to simulate the impact of current water resources management practices in main groundwater budget components and groundwater salinization of the shallow aquifer developed in the area. Moreover, potential climate change impact was investigated using climate data from Regional Climate Model for two projected periods (2021–2050 and 2071–2100) and two sea level rise scenarios (increase by 0.5 and 1 m). Modeling results are providing significant insight: although the contribution of the river to groundwater inflows is significant, direct groundwater recharge from precipitation was found to be higher, while capillary rise constitutes a major part of groundwater outflows from the aquifer. Moreover, during the simulation period, groundwater flow from the aquifer to the sea were found to be higher than the inflows of seawater to the aquifer. Regarding climate change impact assessment, the results indicate that the variability in groundwater recharge posed by the high variability of precipitation during the projected periods is increasing the aquifer’s deterioration potential of both its quantity and quality status, the latter expressed by the increased groundwater Cl− concentration. This evidence becomes more significant because of the limited groundwater storage capacity of the aquifer. Concerning sea level rise, it was found to be less significant in terms of groundwater salinization impact compared to the decrease in groundwater recharge and increase in crop water needs.

Monitoring of Tempi Valley Critical Rock Masses: Establishment of Special Monitoring Network and Procedures in Aegean Motorway S.A. Concession Project

The paper aims to describe the installed monitoring network of critical rock masses stability and deformations and the procedures that are followed by the Concessionaire in order to ensure the safety of users along the National road in Tempi Valley. The road runs between the mountains of Olympus and Ossa in a canyon characterized by steep rock slopes on both sides, parallel to Pinios River that streams through it. The intense discontinuity systems of the rock slopes could activate planar slide of large rock masses, rock wedges as well as individual rockfall events concluding on the pavement during the roadway operation and therefore could cause accidents and damages on the infrastructure. The concessionaire Aegean Motorway S.A. (AMSA) is responsible for the Operation and Maintenance of this road. For this reason, an extensive rockfall protection and stabilization design for the mitigation of rockfall risks along the National road through Tempi Valley was realized in the years 2009 and 2010. A procedure was established as outlined in detail in the Rockfall Protection Inspection and Maintenance Manual (RIMM) setting out the necessary actions for the continuous inspection of the areas of increased rockfall risks within the Concession Project and for the operation and maintenance of the rockfall protection systems. All rockfall measures as well as rock slopes of the valley are being inspected systematically with any new rockfall event and/or damage to the protection measures documented in designated forms. Moreover, a special geodetic monitoring network has been established in critical rock masses with specific warning and alarm thresholds. The monitoring system of critical rock masses in Tempi Valley is enhanced with grout bridges applied to rock discontinuities where movement is supposed to occur prior to failure. All the collected data are the subject of interpretation by rockfall experts in line with the established procedure.

Characteristics of Pinios river delta soils in Greece cultivated with kiwifruit

Kiwifruit (Actinidia chinensis Planch.) is a crop introduced to Greece about 45 years ago, which soon spread in the country, mostly in the Pieria, Imathia, Larissa, and Epirus areas. Nowadays, at the country level, about 6000 ha are cultivated with kiwifruit, showing an increasing trend. About half of this area is in the estuary of the Pinios river, located in the eastern part of the prefecture of Larissa. The purpose of the present study was to investigate the physico-chemical characteristics of the soils on which kiwifruit is grown in order to propose possible ameliorative measures. Over 150 composite surface-soil samples were selected from the whole area and analysed for basic soil physico-chemical and chemical properties related to kiwifruit growth [pH, electrical conductivity (EC), organic matter, calcium carbonate content, available P, K, and B, and metallic micronutrients Fe, Mn, Cu and Zn]. In addition, information from the soil map of the area such as soil texture and soil drainage was combined, and relevant thematic maps were created. Furthermore, leaf samples from 36 groves were selected at appropriate times and analysed for basic macro- and micronutrients (N, P, K, Ca, Mg, B, Fe, Mn, Cu, and Zn). Water samples from the basic water sources of the area also were selected and analysed for properties related to their quality for irrigation [pH, EC, sodium adsorption ratio (SAR), cations (Ca2+, Mg2+, Na+, K+), anions (CO3-, SO42-, NO3-) and B]. According to these results, most of the area cultivated with kiwifruit has medium drainage, but there are also areas with poorly drained soils. Almost all the soils studied have high CaCO3 content, medium EC, lower than desirable exchangeable K and available P but higher than critical B content. In conclusion, these soils are not ideal for kiwifruit growth, needing ameliorative measures and special care in nutrient management.

MCDA approach for agricultural water management in the context of water–energy–land–food nexus

An integrated methodological framework, combining methods for environmental analysis with multi-criteria decision aid (MCDA), is proposed for decision problems related to the selection of agricultural water management measures in river basins. The proposed framework for environmental analysis combines the driving forces–pressures–state–impacts–responses model with the water–energy–land–food (WELF) nexus model to ensure structured, comprehensive and systemic thinking regarding the definition of the alternatives, the points of view and the criteria of the decision problem. The MCDA framework follows a multi-attribute value/utility theory approach for the estimation of marginal value functions for the selected criteria. This process is supported by the multicriteria interactive intelligence decision aiding system. The estimation of points of view and criteria weights is conducted following the newly-established weights assessment through prioritisation method (WAP), which is supported by the relevant WAP software. The MCDA framework includes strong interaction with a decision maker (DM) to elicit the required information for the above methods. Feedback loops and indicators for robustness analysis are applied, aiming at concluding to a robust value system, which models the preferences of the DM as close as possible. An additive value model is used to aggregate all the criteria and express the global value of all examined alternatives. The framework concludes to a recommended alternative for selection by the DM. The strengths and weaknesses of the proposed framework are identified. The framework is applied in a demonstration example from the Pinios river basin in Greece to showcase its use. The outcomes on the potential WELF nexus trade-offs and the identified sources of uncertainty are discussed.

Temporal and Spatial Analysis of Flood Occurrences in the Drainage Basin of Pinios River (Thessaly, Central Greece)

Historic data and old topographic maps include information on historical floods and paleo-floods. This paper aims at identifying the flood hazard by using historic data in the drainage basin of Pinios (Peneus) River, in Thessaly, central Greece. For this purpose, a catalogue of historical flood events that occurred between 1979 and 2010 and old topographic maps of 1881 were used. Moreover, geomorphic parameters such as elevation, slope, aspect and slope curvature were taken into account. The data were combined with the Geographical Information System to analyze the temporal and spatial distribution of flood events. The results show that a total number of 146 flood events were recorded in the study area. The number of flood events reaches its maximum value in the year 1994, while October contains the most flood events. The flood occurrences increased during the period 1990–2010. The flooded area reaches its maximum value in the year 1987, and November is the month with the most records. The type of damages with the most records is for rural land use. Regarding the class of damages, no human casualties were recorded during the studied period. The annual and monthly distribution of the very high category reaches the maximum values, respectively, in the year 2005 and in June. The analysis of the spatial distribution of the floods proves that most of the occurrences are recorded in the southern part of the study area. There is a certain amount of clustering of flood events in the areas of former marshes and lakes along with the lowest and flattest parts of the study area. These areas are located in the central, southern, south-eastern and coastal part of the study area and create favorable conditions for flooding. The proposed method estimates the localization of sites prone to flood, and it may be used for flood hazard assessment mapping and for flood risk management.

Assessment and management of pesticide pollution at a river basin level part I: Aquatic ecotoxicological quality indices

During the last decade numerous monitoring programs have been conducted in order to assess pesticide pollution in catchments. This effort has led to the production of large, complex data sets of environmental results making the task of evaluation of the aquatic chemical status more difficult. Furthermore, the evaluation of the chemical status of the water ecosystems is one of the main aspects which should be considered in a River Basin Management Plan. In this study, two indices were developed in order to assess the combined pesticide ecotoxicity to aquatic non-target organisms, the Aquatic Quality Index of Short term Toxicity of Pesticides (AQI ShToxP) and the Aquatic Quality Index of Long term Toxicity of Pesticides (AQI LToxP). These indices were applied to the environmental results obtained from an intensive monitoring study of 302 pesticides in 102 stationary sampling stations located on the surface aquatic network of the Pinios River Basin, in Greece, in 2011 and 2012. The evaluation of the surface water quality was achieved by taking into consideration the frequency and the intensity of exposure of the aquatic organisms to pesticides above the respective ecotoxicological quality objectives such as the acute or chronic term predicted no-effect concentrations derived from risk assessment. Seventy-five pesticides, that have been previously identified as the River Basin Specific Pollutants of Pinios by an environmental and human risk hierarchy exercise, were assessed. It appears, from the implementation of the two indices, that the detected pesticides in the surface aquatic ecosystem of the Pinios River Basin exert significant pressure on the aquatic non-target organisms especially at the chronic effect level. The developed AQI ShToxP and AQI LToxP indices, as well as the proposed quality classification system could be valuable communication and interpretation tools for River Basin Management Plans that can contribute in the restoration of environmental health.

DRAINAGE NETWORK EVOLUTION OF THE PORTAIKOS RIVER (THESSALY)

Portaikos river is a tributary of Pinios River located in Thessaly. It drains the southern part of Thessaly basin, and specifically the south part of the district of Tricala. This region is located at the border with the district of Karditsa. Portaikos River drainage basin covers an area of 294 km2, which is 2.8 % of the total drainage basin of Pinios River. The direction of Portaikos river drainage basin extends from SW-NE. The evolution of Portaikos River drainage network presents some specific morphometric features. Its analysis required the use of digital data, which were analyzed with G.I.S. software. During the study of the drainage network with the laws of drainage composition, we found a certain deviation of the 4t h and 5t h order streams. Geology has influenced significantly the estimated values of drainage density and frequency of the sub-basins. In some specific areas previous hydrographie features are inherited by the underlying rocks, which constitute the current surface morphology. The analysis of the rose diagrams of the tributaries showed a clear tendency in two main directions. The one extends from NE-SW and the other from NW-SE, almost vertical to each other. To conclude, the hypsometric (area altitude) analysis revealed that Portaikos River drainage network has developed upon a landmass of the western tectonic border of Thessaly basin.

Surface–ground water interactions and hydrogeochemical evolution in a fluvio-deltaic setting: The case study of the Pinios River delta

River deltas sustain important ecosystems with rich biodiversity and large biomass, as well as human populations via the availability of water and food sources. Anthropogenic activities, such as urbanization, tourism and agriculture, may pose threats to river deltas. The knowledge of the factors controlling the regional water quality regime in these areas is important for planning sustainable use and management of the water resources. Here, hydrochemical methods and multivariate statistical techniques were combined to investigate the shallow aquifer of the Pinios River (Thessaly) deltaic plain with respect to water quality, hydrogeochemical evolution and interactions between groundwater and surface water bodies.Water quality assessment indicated that most of the river and groundwater samples fully comply with the criteria set by the Drinking Water Directive (98/83/EC). The river is recharged mainly from springs of the Tempi valley and the shallow aquifer, and to a lesser degree from precipitation, throughout the year. The hydrogeochemical characteristics indicated a cation (Ca, Mg, and Na) bicarbonate water type, which evolves to calcium-chloride, sodium-bicarbonate and sodium-chloride water type, in the northern part of the delta. Calcite and dolomite dissolution determined the major ion chemistry, but other processes, such as silicate weathering and cation exchange reactions, also contributed. In the northern part of the plain, the interaction with the deeper aquifer enriched the shallow aquifer with Na and Cl ions.Principal Component Analysis showed that five components (PCs) explain 77% of the total variance of water quality parameters; these are: (1) salinity; (2) water-silicate rocks interaction; (3) hardness due to calcite dissolution, and cation exchange processes; (4) nitrogen pollution; and (5) non-N-related artificial fertilizers. This study demonstrated that the variation of water hydrochemistry in the deltaic plain could be attributed to natural and anthropogenic processes. The interpretation of the PCA results dictated the parameters used for the development of a modified Water Quality Index (WQI), to provide a more comprehensive spatial representation of the water quality of the river delta.

Identifying potential effects of climate change on the development of water resources in Pinios River Basin, Central Greece

The aim of the present study is to assess the future spatial and temporal distribution of precipitation and temperature, and relate the corresponding change to water resources’ quantitative status in Pinios River Basin (PRB), Thessaly, Greece. For this purpose, data from four Regional Climate Models (RCMs) for the periods 2021–2100 driven by several General Circulation Models (GCMs) were collected and bias-correction was performed based on linear scaling method. The bias-correction was made based on monthly precipitation and temperature data collected for the period 1981–2000 from 57 meteorological stations in total. The results indicate a general trend according to which precipitation is decreasing whilst temperature is increasing to an extent that varies depending on each particular RCM–GCM output. On the average, annual precipitation change for the period 2021–2100 was about − 80 mm, ranging between − 149 and + 35 mm, while the corresponding change for temperature was 2.81 °C, ranging between 1.48 and 3.72 °C. The investigation of potential impacts to the water resources demonstrates that water availability is expected to be significantly decreased in the already water-stressed PRB. The water stresses identified are related to the potential decreasing trend in groundwater recharge and the increasing trend in irrigation demand, which constitutes the major water consumer in PRB.

Response of a multi-stressed Mediterranean river to future climate and socio-economic scenarios

Streams and rivers are among the most threatened ecosystems in Europe due to the combined effects of multiple pressures related to anthropogenic activities. Particularly in the Mediterranean region, changes in hydromorphology along with increased nutrient loadings are known to affect the ecological functions and ecosystem services of streams and rivers with the anticipated climate change being likely to further impair their functionality and structure. In this study, we investigated the combined effects of agricultural driven stressors on the ecology and delivered services of the Pinios river basin in Greece under three future world scenarios developed within the EU funded MARS project. Scenarios are based on combinations of Representative Concentration Pathways and Shared Socioeconomic Pathways and refer to early century (2030) and mid-century (2060) representing future climate worlds with particular socioeconomic characteristics. To assess the responses of ecological and ecosystem service indicators to the scenarios we first simulated hydrology and water quality in Pinios with a process-based model. Simulated abiotic stressor parameters (predictors) were linked to two biotic indicators, the macroinvertebrate indicators ASPT and EPT, with empirical modelling based on boosted regression trees and general linear models. Our results showed that the techno world scenario driven by fast economic growth and intensive exploitation of energy resources had the largest impact on both the abiotic status (nutrient loads and concentrations in water) and the biotic indicators. In contrast, the predicted changes under the other two future worlds, consensus and fragmented, were more diverse and were mostly dictated by the projected climate. This work showed that the future scenarios, especially the mid-century ones, had significant impact on both abiotic status and biotic responses underpinning the need for implementing catchment management practices able to mitigate the ecological threat on waters in the long-term.

Monitoring, modeling, and assessment of water quality and quantity in River Pinios, using ARIMA models

Monitoring, modeling, and assessment of water quality and quantity in River Pinios, using ARIMA models

Hydrologic and Geochemical Research at Pinios Hydrologic Observatory: Initial Results

Core Ideas Modeled ETo gradients present variations as a function of altitude, annual cycle, and total amount. A very good match between different soil moisture monitoring devices has been achieved. Groundwater level monitoring revealed dominant hydrodynamic evolution mechanisms. Hydrochemical monitoring supports groundwater hydrology findings and reveals pollution sources. Monitoring the PHO supports accurate hydrologic modeling and sustainable water use. The Pinios Hydrologic Observatory (PHO) is located in the River Pinios basin, which is one of the most productive basins in Greece. The PHO was established to develop deep knowledge of water balance at the river basin scale and to improve understanding of the major hydrodynamic mechanisms to improve hydrological modeling and ultimately sustainable water resource management. The PHO comprises three meteorological stations, 12 groundwater monitoring sites, and one soil moisture monitoring site, which includes frequency domain reflectometry sensors (SoilNet) and a cosmic‐ray neutron sensor (CRNS) probe. Although the PHO was recently established (at the end of 2015), the preliminary findings from data analysis are promising. Calculated reference evapotranspiration (ETo) gradients demonstrate differences regarding their annual cycle, total amount, and altitude level. Moreover, climate analysis indicates nocturnal mountain‐valley winds. Groundwater level spatial distribution indicates the dominant recharge mechanisms to the alluvial aquifer system. These findings are also supported by the hydrochemical data analysis (electrical conductivity and, secondarily, NO3 distribution). Locally elevated NO3 concentrations are attributed to agricultural activities and call for review of the adopted farming practices. Results from the soil moisture monitoring site indicate a very good match between the CRNS probe and the average SoilNet data. Future perspectives of the PHO include geophysical surveys to accurately delineate the geometry of the groundwater system, the expansion of groundwater and soil moisture observation networks, and the application of the mGROWA hydrologic model to accurately simulate the hydrological processes in the PHO and upscale in the entire River Pinios basin. Finally, in support of the local farmers, we plan to develop and implement a distributed irrigation programming protocol in the entire area of the PHO.