Abstract: Agricultural use is by far the largest consumer of fresh water worldwide, especially in... more Abstract: Agricultural use is by far the largest consumer of fresh water worldwide, especially in the Mediterranean, where it has reached unsustainable levels, thus posing a serious threat to water resources. Having a good estimate of the water used in an agricultural area would help water managers create incentives for water savings at the farmer and basin level, and meet the demands of the European Water Framework Directive. This work presents an integrated methodology for estimating water use in Mediterranean agricultural areas. It is based on well established methods of estimating the actual evapotranspiration through surface energy fluxes, customized for better performance under the Mediterranean conditions: small parcel sizes, detailed crop pattern, and lack of necessary data. The methodology has been tested and validated on the agricultural plain of the river Strimonas (Greece) using a time series of Terra MODIS and Landsat 5 TM satellite images, and used to produce a seasona...
<p>A deeper understanding of the agricultural sector is needed to provide t... more <p>A deeper understanding of the agricultural sector is needed to provide the informed and transparent framework required to meet increasing resource demands and pressures, without compromising sustainability. In this regard, an integrated management of the ecosystems is critical to address the priorities laid out by global policies and, achieve land degradation neutrality and resource efficient regions. Soils are an essential component of the ecosystem, they function as an important carbon storage, and provide the basis of agricultural activity. For the sustainable management of soil resources, and to prevent land degradation the regular assessments of spatially referenced soil conditions is essential. Critical soil properties, such as texture and organic and inorganic carbon content, provides farmers with the information to detect soil vulnerable to soil erosion and land degradation in its early stages in order to locally intervene and to assess soil fertility. Hyperspectral remote sensing been proven to be an effective method for the quantitative prediction of topsoil properties. However, remote sensing observations of the traditionally used visible-near infrared (VNIR) and shortwave infrared (SWIR) wavelength regions (0.4-2.5 µm) can be limited for the estimation of coarse texture soils due to the lack of distinct spectral characteristics of these properties in the VNIR-SWIR (e.g., sand content, quartz and feldspar mineralogy). Spectral information from the longwave infrared region (LWIR, 8-12 μm) has the potential to improve the determination of these properties, due to the presence of fundamental vibration modes of silicate and carbonate minerals, as well carbon-hydrogen bonds in this spectral range.</p><p>The main objective of this study is to evaluate the increased analytical potential of combined VNIR-SWIR and LWIR hyperspectral remote sensing for the estimation of soil properties with the focus on soil organic matter, texture and mineralogical composition. In the frame of EnMAP GFZ/FU airborne campaign in Northern Greece in September 2019, an airborne survey with the HySpex VNIR-SWIR and Hyper-Cam LWIR cameras mounted on a Cessna airplane. A simultaneous ground sampling campaign took place at the agricultural landscape of the Amyntaio region including fields spectroscopy for calibration and validation porpoise, as well as soil sampling of bare soil fields. Fields in the study area have highly variable topsoil composition ranging from silicate to carbonate rich mineralogy, loamy to clay texture and to organic carbon rich fields around a lignite mine in the south-east of the area. Different statistical and machine learning methods such as Partial Least Squares (PLS) and Random Forest (RF) regression are applied to derive soil properties and the variable importance of the spectral dataset is discussed. A further goal of this study is the simulation and validation of the soil products with recent relevant satellite sensors (e.g., EnMAP, PRISMA, ECOSTRESS), as well as upcoming next generation of hyperspectral optical and thermal multispectral satellite missions (ESA CHIME and LSTM, NASA/JPL SBG) to evaluate their potential for quantitative soil properties mapping.</p>
In 1992, the Greek Biotope/Wetland Centre undertook a project to design and conduct an inventory ... more In 1992, the Greek Biotope/Wetland Centre undertook a project to design and conduct an inventory of Greek wetlands. The reasons for initiating this effort were: a) to monitor the status and trends of Greek wetlands, b) to be able to widely disseminate scientific information on the characteristics and area of Greek wetlands, and c) to support, protect and conserve these important resources. The long term goal is to develop a comprehensive database concerning the number, area, functions, and important characteristics of Greek wetlands, as well as the pressures threatening them. It was clear that this database had to be compatible with other databases worldwide. Thus the Ramsar Convention's Wetland Information Sheet was used as a basis, being subsequently modified and simplified to meet local requirements. The aim of the first phase of the project, in 1992, was to obtain information from people involved with Greek wetlands. The aim of the second phase is to formate this information in to a publishable form. The Ministries of Environment and Agriculture and the nature oriented Non-Governmental Organizations (NGO) of Greece are the main networks through which raw data are being collected. Care was taken to make the questionnaire relatively simple and easy to be answered through these networks. In the second phase, a committee of wetland scientists appointed by the Greek Wetland Centre will cross-check the reliability of the raw data and subsequently complete a detailed data sheet for each site. The same committee will also draw general conclusions and assist in the drafting of a report on the status of Greek Wetlands in 1992.
Capillary rise experiments were performed under constant temperature in columns of Metea sandy lo... more Capillary rise experiments were performed under constant temperature in columns of Metea sandy loam soil packed at different bulk densities. Moisture retention curves were obtained following the capillary rise activity. All curves exhibited a theta-straight region, followed by a parabolic region flattened at higher suctions. The parabolic region, when plotted on log-log scales, could be separated into three distinct zones in all none soil retention curves. These three zones suggest sharp transitions in the water content-matric potential relationship rather than the expected gradual change in a continuum. A power function was used to fit each of the three zones of wetting retention data. Comparison of retention curves obtained through capillary rise and steady-state equilibrium standard methods showed significant differences at high suction values. These retention curve differences were attributed to the reduction of the matric field for liquid phase wetting of capillary rise. Conductivity and diffusivity functions suitable for predicting upward water movement with infiltration models were determined from experimental retention data by applying the zonal constitutive relationships.
A navegação consulta e descarregamento dos títulos inseridos nas Bibliotecas Digitais UC Digitali... more A navegação consulta e descarregamento dos títulos inseridos nas Bibliotecas Digitais UC Digitalis, UC Pombalina e UC Impactum, pressupõem a aceitação plena e sem reservas dos Termos e Condições de Uso destas Bibliotecas Digitais, disponíveis em https://digitalis.uc.pt/pt-pt/termos. Conforme exposto nos referidos Termos e Condições de Uso, o descarregamento de títulos de acesso restrito requer uma licença válida de autorização devendo o utilizador aceder ao(s) documento(s) a partir de um endereço de IP da instituição detentora da supramencionada licença. Ao utilizador é apenas permitido o descarregamento para uso pessoal, pelo que o emprego do(s) título(s) descarregado(s) para outro fim, designadamente comercial, carece de autorização do respetivo autor ou editor da obra. Na medida em que todas as obras da UC Digitalis se encontram protegidas pelo Código do Direito de Autor e Direitos Conexos e demais legislação aplicável, toda a cópia, parcial ou total, deste documento, nos casos em que é legalmente admitida, deverá conter ou fazer-se acompanhar por este aviso.
Wastewater collection and treatment is an important parameter of sustainable development. In Medi... more Wastewater collection and treatment is an important parameter of sustainable development. In Mediterranean region especially, the design and operation of competitive wastewater treatment systems for small communities and touristic facilities is a challenge to wastewater engineers. Within this context an alternative method of wastewater treatment has been developed that is based on solar photocatalytic oxidation and natural processes. The system combines the synergetic action of the homogeneous photocatalytic oxidation with the surface flow constructed wetlands in order to utilize the high solar irradiation and the ability of the constructed wetlands to improve water quality through natural processes. Aim of this work is to present the design, development, and experimental evaluation of the combined system. Experiments were conducted at laboratory scale using artificial as well as solar irradiation, for the treatment of both synthetic and cesspool wastewater. The data evaluation revealed that the combined system may effectively reduce the organic load and nutrients of wastewater, even in cases of great inflow variability, in terms of hydraulic and organic load, and thus may be proven a promising, competitive and environmental friendly solution for wastewater treatment in the near future.
International Journal of Environmental Analytical Chemistry, Oct 15, 2012
ABSTRACT This paper describes the development of a new analytical method for the analysis of the ... more ABSTRACT This paper describes the development of a new analytical method for the analysis of the herbicide TER and its degradation products in sediment samples. This method, based on high-performance liquid chromatography with diode-array detection, was validated for the simultaneous determination of TER and its major metabolites, desethylterbuthylazine, desisopropyatrazine, hydroxyterbuthylazine, desethylhydroxyatrazine and desethylhydroxyterbuthylazine. This method includes a cleanup and a solid-phase extraction step, using ultra-pure water and MCX cartridges respectively, with an overall recovery efficiency ranging from 89.3 to 97.9%. The statistical evaluation demonstrates good linearity with correlation coefficients >0.999 and adequate accuracy and precision for all analytes, with% Er and RSD values up to 10.5% and 8.3% respectively. The limit of detection for all substances was found to be 3.3 ng g−1. This method can be employed in remediation studies of TER and its major metabolites in sediments of constructed wetlands leading to useful results for the degradation and dispersion of TER in the vertical profile of wetland sediment substrates.
This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY
This chapter presents a Boosted Genetic Fuzzy Classifier (BGFC), for land cover classification fr... more This chapter presents a Boosted Genetic Fuzzy Classifier (BGFC), for land cover classification from multispectral images. The model comprises a set of fuzzy classification rules, which resemble the reasoning employed by humans. BGFC's learning algorithm is divided into two stages. During the first stage, a number of fuzzy rules are generated in an iterative fashion, incrementally covering subspaces of the feature space, as directed by a boosting algorithm. Each rule is able to select the required features, further improving the interpretability of the obtained model. The rule base generation stage is followed by a genetic tuning stage, aiming at improving the cooperation among the fuzzy rules and, subsequently, increasing the classification performance attained after the former stage. The BGFC is tested using an IKONOS multispectral VHR image, in a lake-wetland ecosystem of international importance. For effective classification, we consider advanced feature sets, containing spectral and textural feature types. The results indicate that the proposed system is able to handle multi-dimensional feature spaces, effectively exploiting information from different feature sources.
Land degradation is a global topic in climate change debates resulted from different types of hum... more Land degradation is a global topic in climate change debates resulted from different types of human activities as well as from physical processes. Resilient, healthy soils are important to help reduce the ecological and economic impact of environmental change and extreme conditions. The development of adequate and broadly applicable indicators and thresholds is challenged by the great diversity of European soils and climate, as well as different political, economic, and social conditions which lead to different priority settings for targets and indicators. This work built upon current environmental awareness (e.g CAP, SDGs, etc.) to design a methodological framework for environmental performance metrics related to land degradation. The framework was oriented towards a data-driven environmental metric approach leveraging Copernicus Sentinel-2, existing open-access databases such as LUCAS (Land Use/Cover Area frame statistical Survey) and GEOSS (e.g., Soil Grids) vast dataset archives to provide metrics for environmental actors. Based both on the international literature and European commission documentations this work is focused on the combination of vital importance indicators of soil degradation and soil health. A novel deep learning architecture was implemented to support the final knowledge extraction with a pixel-based spatial resolution of 10m for the determination of Soil Organic Carbon (SOC) and Clay content. The above indicators are used as enhanced geospatial inputs to a soil erosion modelling approach providing improved predictions. A proper approach was followed for the SOC:clay ratio generation and with the soil erosion product combination to provide an ambitious land degradation index. An agricultural area in Northern Greece was used as a demonstration test site area for the proposed methodology.
Abbreviations: HB, Munsell color book readings by horizon; HC, chroma meter readings by horizon; ... more Abbreviations: HB, Munsell color book readings by horizon; HC, chroma meter readings by horizon; IB, Munsell color book readings by depth increment; IC, chroma meter readings by depth increment; SCd, chroma meter readings on dry samples; SCm, chroma meter readings on moist samples; SOC, soil organic carbon.
Abstract: Agricultural use is by far the largest consumer of fresh water worldwide, especially in... more Abstract: Agricultural use is by far the largest consumer of fresh water worldwide, especially in the Mediterranean, where it has reached unsustainable levels, thus posing a serious threat to water resources. Having a good estimate of the water used in an agricultural area would help water managers create incentives for water savings at the farmer and basin level, and meet the demands of the European Water Framework Directive. This work presents an integrated methodology for estimating water use in Mediterranean agricultural areas. It is based on well established methods of estimating the actual evapotranspiration through surface energy fluxes, customized for better performance under the Mediterranean conditions: small parcel sizes, detailed crop pattern, and lack of necessary data. The methodology has been tested and validated on the agricultural plain of the river Strimonas (Greece) using a time series of Terra MODIS and Landsat 5 TM satellite images, and used to produce a seasona...
<p>A deeper understanding of the agricultural sector is needed to provide t... more <p>A deeper understanding of the agricultural sector is needed to provide the informed and transparent framework required to meet increasing resource demands and pressures, without compromising sustainability. In this regard, an integrated management of the ecosystems is critical to address the priorities laid out by global policies and, achieve land degradation neutrality and resource efficient regions. Soils are an essential component of the ecosystem, they function as an important carbon storage, and provide the basis of agricultural activity. For the sustainable management of soil resources, and to prevent land degradation the regular assessments of spatially referenced soil conditions is essential. Critical soil properties, such as texture and organic and inorganic carbon content, provides farmers with the information to detect soil vulnerable to soil erosion and land degradation in its early stages in order to locally intervene and to assess soil fertility. Hyperspectral remote sensing been proven to be an effective method for the quantitative prediction of topsoil properties. However, remote sensing observations of the traditionally used visible-near infrared (VNIR) and shortwave infrared (SWIR) wavelength regions (0.4-2.5 µm) can be limited for the estimation of coarse texture soils due to the lack of distinct spectral characteristics of these properties in the VNIR-SWIR (e.g., sand content, quartz and feldspar mineralogy). Spectral information from the longwave infrared region (LWIR, 8-12 μm) has the potential to improve the determination of these properties, due to the presence of fundamental vibration modes of silicate and carbonate minerals, as well carbon-hydrogen bonds in this spectral range.</p><p>The main objective of this study is to evaluate the increased analytical potential of combined VNIR-SWIR and LWIR hyperspectral remote sensing for the estimation of soil properties with the focus on soil organic matter, texture and mineralogical composition. In the frame of EnMAP GFZ/FU airborne campaign in Northern Greece in September 2019, an airborne survey with the HySpex VNIR-SWIR and Hyper-Cam LWIR cameras mounted on a Cessna airplane. A simultaneous ground sampling campaign took place at the agricultural landscape of the Amyntaio region including fields spectroscopy for calibration and validation porpoise, as well as soil sampling of bare soil fields. Fields in the study area have highly variable topsoil composition ranging from silicate to carbonate rich mineralogy, loamy to clay texture and to organic carbon rich fields around a lignite mine in the south-east of the area. Different statistical and machine learning methods such as Partial Least Squares (PLS) and Random Forest (RF) regression are applied to derive soil properties and the variable importance of the spectral dataset is discussed. A further goal of this study is the simulation and validation of the soil products with recent relevant satellite sensors (e.g., EnMAP, PRISMA, ECOSTRESS), as well as upcoming next generation of hyperspectral optical and thermal multispectral satellite missions (ESA CHIME and LSTM, NASA/JPL SBG) to evaluate their potential for quantitative soil properties mapping.</p>
In 1992, the Greek Biotope/Wetland Centre undertook a project to design and conduct an inventory ... more In 1992, the Greek Biotope/Wetland Centre undertook a project to design and conduct an inventory of Greek wetlands. The reasons for initiating this effort were: a) to monitor the status and trends of Greek wetlands, b) to be able to widely disseminate scientific information on the characteristics and area of Greek wetlands, and c) to support, protect and conserve these important resources. The long term goal is to develop a comprehensive database concerning the number, area, functions, and important characteristics of Greek wetlands, as well as the pressures threatening them. It was clear that this database had to be compatible with other databases worldwide. Thus the Ramsar Convention's Wetland Information Sheet was used as a basis, being subsequently modified and simplified to meet local requirements. The aim of the first phase of the project, in 1992, was to obtain information from people involved with Greek wetlands. The aim of the second phase is to formate this information in to a publishable form. The Ministries of Environment and Agriculture and the nature oriented Non-Governmental Organizations (NGO) of Greece are the main networks through which raw data are being collected. Care was taken to make the questionnaire relatively simple and easy to be answered through these networks. In the second phase, a committee of wetland scientists appointed by the Greek Wetland Centre will cross-check the reliability of the raw data and subsequently complete a detailed data sheet for each site. The same committee will also draw general conclusions and assist in the drafting of a report on the status of Greek Wetlands in 1992.
Capillary rise experiments were performed under constant temperature in columns of Metea sandy lo... more Capillary rise experiments were performed under constant temperature in columns of Metea sandy loam soil packed at different bulk densities. Moisture retention curves were obtained following the capillary rise activity. All curves exhibited a theta-straight region, followed by a parabolic region flattened at higher suctions. The parabolic region, when plotted on log-log scales, could be separated into three distinct zones in all none soil retention curves. These three zones suggest sharp transitions in the water content-matric potential relationship rather than the expected gradual change in a continuum. A power function was used to fit each of the three zones of wetting retention data. Comparison of retention curves obtained through capillary rise and steady-state equilibrium standard methods showed significant differences at high suction values. These retention curve differences were attributed to the reduction of the matric field for liquid phase wetting of capillary rise. Conductivity and diffusivity functions suitable for predicting upward water movement with infiltration models were determined from experimental retention data by applying the zonal constitutive relationships.
A navegação consulta e descarregamento dos títulos inseridos nas Bibliotecas Digitais UC Digitali... more A navegação consulta e descarregamento dos títulos inseridos nas Bibliotecas Digitais UC Digitalis, UC Pombalina e UC Impactum, pressupõem a aceitação plena e sem reservas dos Termos e Condições de Uso destas Bibliotecas Digitais, disponíveis em https://digitalis.uc.pt/pt-pt/termos. Conforme exposto nos referidos Termos e Condições de Uso, o descarregamento de títulos de acesso restrito requer uma licença válida de autorização devendo o utilizador aceder ao(s) documento(s) a partir de um endereço de IP da instituição detentora da supramencionada licença. Ao utilizador é apenas permitido o descarregamento para uso pessoal, pelo que o emprego do(s) título(s) descarregado(s) para outro fim, designadamente comercial, carece de autorização do respetivo autor ou editor da obra. Na medida em que todas as obras da UC Digitalis se encontram protegidas pelo Código do Direito de Autor e Direitos Conexos e demais legislação aplicável, toda a cópia, parcial ou total, deste documento, nos casos em que é legalmente admitida, deverá conter ou fazer-se acompanhar por este aviso.
Wastewater collection and treatment is an important parameter of sustainable development. In Medi... more Wastewater collection and treatment is an important parameter of sustainable development. In Mediterranean region especially, the design and operation of competitive wastewater treatment systems for small communities and touristic facilities is a challenge to wastewater engineers. Within this context an alternative method of wastewater treatment has been developed that is based on solar photocatalytic oxidation and natural processes. The system combines the synergetic action of the homogeneous photocatalytic oxidation with the surface flow constructed wetlands in order to utilize the high solar irradiation and the ability of the constructed wetlands to improve water quality through natural processes. Aim of this work is to present the design, development, and experimental evaluation of the combined system. Experiments were conducted at laboratory scale using artificial as well as solar irradiation, for the treatment of both synthetic and cesspool wastewater. The data evaluation revealed that the combined system may effectively reduce the organic load and nutrients of wastewater, even in cases of great inflow variability, in terms of hydraulic and organic load, and thus may be proven a promising, competitive and environmental friendly solution for wastewater treatment in the near future.
International Journal of Environmental Analytical Chemistry, Oct 15, 2012
ABSTRACT This paper describes the development of a new analytical method for the analysis of the ... more ABSTRACT This paper describes the development of a new analytical method for the analysis of the herbicide TER and its degradation products in sediment samples. This method, based on high-performance liquid chromatography with diode-array detection, was validated for the simultaneous determination of TER and its major metabolites, desethylterbuthylazine, desisopropyatrazine, hydroxyterbuthylazine, desethylhydroxyatrazine and desethylhydroxyterbuthylazine. This method includes a cleanup and a solid-phase extraction step, using ultra-pure water and MCX cartridges respectively, with an overall recovery efficiency ranging from 89.3 to 97.9%. The statistical evaluation demonstrates good linearity with correlation coefficients >0.999 and adequate accuracy and precision for all analytes, with% Er and RSD values up to 10.5% and 8.3% respectively. The limit of detection for all substances was found to be 3.3 ng g−1. This method can be employed in remediation studies of TER and its major metabolites in sediments of constructed wetlands leading to useful results for the degradation and dispersion of TER in the vertical profile of wetland sediment substrates.
This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY
This chapter presents a Boosted Genetic Fuzzy Classifier (BGFC), for land cover classification fr... more This chapter presents a Boosted Genetic Fuzzy Classifier (BGFC), for land cover classification from multispectral images. The model comprises a set of fuzzy classification rules, which resemble the reasoning employed by humans. BGFC's learning algorithm is divided into two stages. During the first stage, a number of fuzzy rules are generated in an iterative fashion, incrementally covering subspaces of the feature space, as directed by a boosting algorithm. Each rule is able to select the required features, further improving the interpretability of the obtained model. The rule base generation stage is followed by a genetic tuning stage, aiming at improving the cooperation among the fuzzy rules and, subsequently, increasing the classification performance attained after the former stage. The BGFC is tested using an IKONOS multispectral VHR image, in a lake-wetland ecosystem of international importance. For effective classification, we consider advanced feature sets, containing spectral and textural feature types. The results indicate that the proposed system is able to handle multi-dimensional feature spaces, effectively exploiting information from different feature sources.
Land degradation is a global topic in climate change debates resulted from different types of hum... more Land degradation is a global topic in climate change debates resulted from different types of human activities as well as from physical processes. Resilient, healthy soils are important to help reduce the ecological and economic impact of environmental change and extreme conditions. The development of adequate and broadly applicable indicators and thresholds is challenged by the great diversity of European soils and climate, as well as different political, economic, and social conditions which lead to different priority settings for targets and indicators. This work built upon current environmental awareness (e.g CAP, SDGs, etc.) to design a methodological framework for environmental performance metrics related to land degradation. The framework was oriented towards a data-driven environmental metric approach leveraging Copernicus Sentinel-2, existing open-access databases such as LUCAS (Land Use/Cover Area frame statistical Survey) and GEOSS (e.g., Soil Grids) vast dataset archives to provide metrics for environmental actors. Based both on the international literature and European commission documentations this work is focused on the combination of vital importance indicators of soil degradation and soil health. A novel deep learning architecture was implemented to support the final knowledge extraction with a pixel-based spatial resolution of 10m for the determination of Soil Organic Carbon (SOC) and Clay content. The above indicators are used as enhanced geospatial inputs to a soil erosion modelling approach providing improved predictions. A proper approach was followed for the SOC:clay ratio generation and with the soil erosion product combination to provide an ambitious land degradation index. An agricultural area in Northern Greece was used as a demonstration test site area for the proposed methodology.
Abbreviations: HB, Munsell color book readings by horizon; HC, chroma meter readings by horizon; ... more Abbreviations: HB, Munsell color book readings by horizon; HC, chroma meter readings by horizon; IB, Munsell color book readings by depth increment; IC, chroma meter readings by depth increment; SCd, chroma meter readings on dry samples; SCm, chroma meter readings on moist samples; SOC, soil organic carbon.
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