
Nektarios KourgialasHellenic Agricultural Organization - Dimitra
Nektarios Kourgialas
BSc/MSc/PhD Hydro-Environmental Engineering
About
105
Publications
49,658
Reads
How we measure 'reads'
A 'read' is counted each time someone views a publication summary (such as the title, abstract, and list of authors), clicks on a figure, or views or downloads the full-text. Learn more
2,909
Citations
Introduction
Dr. Kourgialas is Researcher, Head of Water Resources, Irrigation & Env. Geoinformatics Lab. - Institute of Olive Tree Subtropical Crops and Viticulture (IOSV) - HELLENIC AGRICULTURAL ORGANIZATION "DIMITRA"- DG AGRICULTURAL RESEARCH.
Research in Water Resources & Irrigation, Modeling & Geoinfomatics/GIS, Extreme Hydrology, Climate-Water effects on Agriculture.
He has 65 journal publications, more than 100 conference papers, 2 books and several book chapters. Editor in Chief IWA: Water Supply.
Additional affiliations
January 2013 - February 2017
January 2010 - February 2017
Publications
Publications (105)
A new integrated national scale flood hazard mapping method based on GIS and ANN techniques • This study provides, for the first time, a flood hazard map for entire Greece. • The methodology was validated based on historical flood events. • 24% of the total area of Greece is under very high flood hazard (50-year return period). Editor: Simon Pollar...
Water scarcity in the Mediterranean region is becoming a growing concern, threatening the viability of agriculture, which is one of the main economic sectors in many areas. The design of an optimal irrigation management plan, based on state-of-the-art measuring and modeling tools, can effectively contribute towards water saving efforts and potentia...
Hydrological extremes such as droughts and floods are recognized as environmental disasters causing several negative effects especially on the agricultural section. These phenomena and their proper management have attracted the attention of hydrologists and agricultural scientists. This paper evaluates the climate change effects on hydrological ext...
Τhe management and protection of a country's water resources is a matter of high priority, ensuring the development and socio-economic stability of a country. Unquestionably, Greece is a characteristic example of this, as water distribution is highly spatially and temporally unequally distributed, while irrigation and tourist consumers as well as t...
This editorial paper takes the form of a concise report and delves into a critical and intricate issue essential for the sustainability of agriculture. It centers on the intricate relationship between agri-cultural water resource management and agronomical practices, as well as their ability to adapt to the impacts of climate change while ensuring...
Irrigated agriculture is the world’s largest water user. It has been estimated that in order to satisfy food demand during the next 30 years, world food production must increase by 70%. Considering that most of the agriculture in the world is rainfed, an important strategy to achieve the above objective is the transition from rainfed to irrigated a...
Agriculture has been shaping the landscape of Greece for thousands of years. Following a dynamic change in the twentieth century by expansion of olive groves, landscape seems relatively stable during the past two decades. During the recent decade, minimum tillage practice has gained wide adoption by olive farmers all over Greece in the framework of...
Agriculture in the Mediterranean region is increasingly impacted by climate change, leading to challenges such as droughts, soil erosion, and water scarcity. This study investigates the sustainability of intensive olive farming practices and their impact on soil health, water management, and olive oil quality. Field experiments were conducted in th...
Due to the multiple pressures from human activities, many freshwater ecosystems are facing degradation. To address this issue, a new approach for assessing stream water quality and ecological (WQE) risk using a multi-criteria analysis through a GIS-based policy tool has been developed. The suggested methodology integrates eight different factors al...
The aim of this communication article is to present a successful irrigation advisory scheme on the island of Crete (Greece) provided by the Hellenic Agricultural Organization (ELGO DIMITRA), which is well adapted to the different needs of farmers and water management agencies. The motivation to create this advisory scheme stems from the need to sav...
Citrus trees and their fruits have significant nutritional value and contain antioxidants that are important components of the Mediterranean diet. However, pathogenic diseases pose a threat to citriculture by reducing crop yield and quality. Therefore, there is a need for novel technologies to maintain healthy citrus crops and enable early and accu...
In order to ensure sustainability in the agricultural sector and to meet global food needs, a particularly important challenge for our time is to investigate the possibility of increasing agricultural production in areas with extreme hyper-arid environments. Warming air temperatures and sandy soils significantly influence tree root water uptake (RW...
Sustainable agriculture largely depends on the stability of the soil ecosystem and the hydrological cycle dynamics [...]
The objective of our investigation was to study the various effects of correct and incorrect application of fuzziness exponent, initial parameterization and fuzzy classification algorithms modeling on homogeneous management zones (MZs) delineation of a Coriandrum sativum L. field by using precision agriculture, soil chemical, granular and hydraulic...
Water Supply is an internationally renowned, fully Open Access, scientific journal, with a context inextricably linked, throughout time and even more so in modern times, to food security, the sustainability of ecosystems and well-functioning societies. In line with this, we are very delighted to serve as the new Editors-in-Chief of Water Supply and...
Precision agriculture (PA), management zone (MZ) strategies at the field level, soil analyses, deficit irrigation (DI), and fertilizer Variable Rate Application (VRA) are management strategies that help farmers improve crop production, fertilizer use efficiency, and irrigation water use efficiency (IWUE). In order to further investigate these manag...
Avocado (Persea americana Mill.) is a tropical fruit that has gained immense popularity worldwide due to its unique flavor, nutritional value, and numerous health benefits. The growth and maturation of avocados are influenced by various environmental and climatic factors. Temperature is one of the most critical factors, as it plays a significant ro...
Climate change has reduced the availability of good quality water for agriculture, while favoring the proliferation of harmful insects, especially in Mediterranean areas. Deploying IoT-based systems can help optimize water-use efficiency in agriculture and address problems caused by extreme weather events. This work presents an IoT-based monitoring...
Field trials were conducted at traditional Mediterranean olive agro-ecosystems grown at two locations (Italy –IT, Greece –GR). Groves were managed for many years using sustainable (S, cover crops, compost application, mulching of pruning biomass) or conventional (C) practices (e.g., soil tillage, burning of pruning residuals). The IT grove was rain...
Orchards with tree crops are of critical importance to the global economy and to the environment due to their ability to be productive for many years without the need for replanting. They are also better adapted to extreme climatic conditions compared to other crops. However, new challenges are emerging as climate change threatens both tree product...
Despite the fact that the olive tree is one of the best-adapted species in Mediterranean hydroclimate conditions, climate extremes impose negative effects on olive fruit set and development and subsequently on crop yield. Considering that the frequency of climate extremes is increasing in the last years due to climate change, Good Agricultural Prac...
The major global challenge for the coming decades will be increasing crop production with less water consumption. Precision agriculture (PA) and variable deficit irrigation (VDI) are management strategies that help farmers to improve crop production, fertilizer’s efficiency, and water use efficiency (WUE). The effects of irrigation (IR1 = variable...
Thorough knowledge of soil lithology and its properties are of considerable importance to
agriculture. These parameters have a direct impact on water permeability and the content of the water in soil, which represent significant factors in crop yield, decisively determining the design of irrigation systems and farming processes. In the framework of...
The aim of this paper is the creation of an integrated and free-access web platform for parcel irrigation water management on a large spatial scale (Water District of Crete, in Greece) in order to: a) accurately determine the irrigation needs of the main crops for Crete such as olives, citrus, avocados and vineyards, b) design strategies, for optim...
Sustainable agriculture management typically requires detailed characterization of physical, chemical, and biological aspects of soil properties. These properties are essential for agriculture and should be determined before any decision for crop type selection and cultivation practices. Moreover, the implementation of soil characterization at the...
Food and water security are considered the most critical issues globally due to the projected population growth placing pressure on agricultural systems. Because agricultural activity is known to be the largest consumer of freshwater, the unsustainable irrigation water use required by crops to grow might lead to rapid freshwater depletion. Precisio...
Could advances in geoinformatics, irrigation management and climate adaptive agronomic practices ensure the sustainability of water supply in agriculture? This book comprises 33 chapters that contribute to a broad discussion and demonstration of state-of-the-art multifunctional role of water resources in agriculture. The aim of the book to provide...
Could advances in geoinformatics, irrigation management and climate adaptive agronomic practices ensure the sustainability of water supply in agriculture? This book comprises 33 chapters that contribute to a broad discussion and demonstration of state-of-the-art multifunctional role of water resources in agriculture. The aim of the book to provide...
Could advances in geoinformatics, irrigation management and climate adaptive agronomic practices ensure the sustainability of water supply in agriculture? This book comprises 33 chapters that contribute to a broad discussion and demonstration of state-of-the-art multifunctional role of water resources in agriculture. The aim of the book to provide...
Among the various abiotic stresses, drought is the major factor limiting crop productivity worldwide. Citrus has been recognized as a fruit tree crop group of great importance to the global agricultural sector since there are 140 citrus-producing countries worldwide. The majority of citrus-producing areas are subjected to dry and hot summer weather...
The production and consumption of avocado has increased significantly over the past years, experiencing a steady expansion into new markets around the world. This review paper focuses on avocado cultivation in its new markets with hot-summer Mediterranean climate. A significant literature gap exists on the viability of this crop in such data enviro...
The aim of this study is the assessment of desertification risk for a typical Mediterranean island, in the frame of climate change and the application of good agricultural practices. Based on the MEDALUS Environmentally Sensitive Area Index (ESAI) approach, the sensitivity in desertification is estimated by employing 15 quantitative parameters divi...
Two strategies of irrigation were applied during the phase of fruit growth in 30-year-old grapefruit trees (Citrus paradisi Mac.) of four varieties (cv. Marsh SRA 8, cv. Shambar SRA 22, cv. Frost Marsh, cv. Ruby). For the first strategy (T1), the trees were irrigated every week at 100% crop evapotranspiration (ETc), while for the second strategy (T...
We use constant velocity migration of Ground Penetrating Radar (GPR) sections over a predefined range of
migration velocities for the validation of diffraction focusing, using local slopes distribution, with the scope to
estimate a migration velocity model. We avoid the user dependent diffraction analysis to circumvent subjectivity
and use overlapp...
In this study a new method for predicting soybean yield over large spatial scales, overcoming the difficulties of scalability, is proposed.
The method is based on the so-called “simplified triangle” remote sensing technique which is coupled with a crop prediction model of
Doorenbos and Kassam 1979 (DK) and the climatological water balance model of...
Olive cultivation is considered as one of the most significant agricultural activities in Greece, from a financial, social, and ecological point of view. Intensive cultivation practices in combination with the Mediterranean climate, lead to depletion of soil organic matter, erosion, desertification, and degradation of water resources. This paper de...
Olive cultivation is considered as one of the most significant agricultural activities in Greece, from a financial, social, and ecological point of view. Intensive cultivation practices in combination with the Mediterranean climate, lead to depletion of soil organic matter, erosion, desertification, and degradation of water resources. This paper de...
Food security and access to electricity are considered core elements forthedevelopment of modern societies. In some cases, energy supplies are prioritized and therefore may compete with food resources. Since 2009, the sudden increase of photovoltaic system investments in Greece and particularly in Crete, as an effort to comply with the European dir...
Soil moisture represents a vital component of the ecosystem, sustaining life-supporting activities at micro and mega scales. It is a highly required parameter that may vary significantly both spatially and temporally. Due to this fact, its estimation is challenging and often hard to obtain especially over large, heterogeneous surfaces. This study a...
Soil moisture represents a vital component of the ecosystem, sustaining life-supporting activities at micro and mega scales. It is a highly required parameter that may vary significantly both spatially and temporally. Due to this fact, its estimation is challenging and often hard to obtain especially over large, heterogeneous surfaces. This study a...
Olive trees constitute one of the most dynamic cultivations for Mediterranean countries, while their
economic importance is high. As water constitutes a fundamental factor affecting olive tree
production, soil water content is a most critical parameter that must be monitored to improve olive
trees’ cultivation management. Effects of precipitation,...
The objective of this work was to classify and map the areas environmentally sensitive to
desertification in the Mediterranean island of Crete. Sensitivity to desertification was estimated with
a modification of the MEDALUS Environmentally Sensitive Area Index (ESAI) approach, using 15
quantitative parameters divided in four main quality indices: c...
The objective of this work was the estimation of time-space hydraulic (water depth, flow velocity) and morphological (sediment transport and bank erosion) characteristics in the downstream part of a Mediterranean stream under current and future climatic conditions. The two-dimensional hydraulic model MIKE 21C was used, which has been developed spec...
This paper presents a new integrated GIS modeling method to assess drought vulnerability using multi-criteria analysis. The proposed methodology is an improvement over previous methods since it incorporates both dynamic and static factors that may affect water dynamics and contribute to water scarcity. These factors are: a) precipitation, b) evapot...
Under the European Commission's LIFE + program, the 5-year oLIVECLIMA project is being implemented, aiming at transforming olive oil into a tool for tackling / managing climate change, as well as adjusting olive oil to new climatic conditions. In olive groves in the Prefecture of Heraklion (EAS Pezon) and in Lassithi (EAS of Meramvello) cultivation...
Under the European Commission's LIFE + program, the 5-year oLIVECLIMA project is being implemented to transform olive growing into a tool for tackling / managing climate change and to adapt olive growing to new climatic conditions. One of the practices applied is the composting of olives by-products or alternatively other crops for the purpose of r...
Under the European Commission's LIFE + program, the 5-year oLIVECLIMA project is being implemented, aiming at transforming olive growing into a tool for tackling / managing climate change and adapting olive growing to new climatic conditions. Among other things, the maintenance of natural weed grass (avoiding soil treatment and chemical weed contro...
A field experiment was conducted in an irrigated olive orchard to determine the effects of an orchard management system consisting of increased carbon input management i.e. olive mill compost or pruning residue and their combination, on spatial distribution (tree inter-row/in-row, soil depth 0-10/10-20 cm) of nitrogen and carbon in the soil as well...
In this 4-year study, the effects of (a) sustainable soil management with weed mowing during spring
and addition of compost without tillage (SUST) and (b) intensive management with soil tillage and
use of herbicides (INT) on soil properties related to water storage and salinity were determined in a
drip-irrigated olive orchard in Crete, Greece. Hig...
In many Mediterranean islands with limited surface water resources, the growth of agricultural and touristic sectors, which are the main water consumers, highly depends on the sustainable water resources management. This work highlights the crucial role of groundwater footprint (GF) as a tool for the sustainable management of water resources, espec...
The objective of this work was the simulation of groundwater flow at the aquifer of the Chania plain area in Crete, Greece. This area is dominated by irrigated olive and citrus trees with high water demands during the dry period. In the present study, the three-dimensional Princeton Transport Code (PTC) model was employed in combination with the pr...
In the present work, a two-dimensional hydraulic model was used for the simulation of river flow and sediment transport at the downstream section of the Koiliaris River Basin in Crete-Greece based on two different structured grids. Specifically, an important goal of the present study was the comparison of a curvilinear grid model with a rectilinear...
A viable approach for flood and groundwater management in a mountain Plateau based on geoinformatics techniques is presented in this work. The proposed water management plan has two components: (a) the determination of the flood-hazard areas, and (b) the estimation of groundwater flow. For the first component, six factors were considered in order t...
In the present work, the two-dimensional hydraulic models MIKE 21 and MIKE 21C were used in order to simulate the water depth at the downstream section of the Koiliaris River Basin in Crete-Greece. Specifically, an important goal of the present study was the comparison of the widely used MIKE 21 with the MIKE 21C model. The MIKE 21C model has been...
Olive growing counts as one of the most significant agricultural activities in Greece, from a financial, social and ecological point of view. Modern olive culture often includes exhaustive use of the available water resources having as a result adverse effects for production cost and the environment. This paper evaluates seasonal soil moisture cont...
The objective of this work is the simulation of the water depth, flow velocity and sediment transport in the downstream part of the Koiliaris River (Crete – Greece). The two-dimensional hydraulic model MIKE 21C is used, which has been developed specifically to simulate 2D flows and morphological changes in rivers. The model is based on an orthogona...
The sustainability of protected horticultural crops in the Mediterranean region, typically under deficit irrigation and intensive cultivation practices, is facing increasing risks due to soil salinization. Climate change may augment this threat to ecosystem services. In this study, the SALTMED leaching requirements model was calibrated using soil m...
In this work a dynamic GIS modeling approach is presented that incorporates: a) geoinformatic techniques, b) 55 years historical meteorological data, and c) field measurements, in order to estimate soil erosion risk in intensively cultivated regions. The proposed GIS-based modeling approach includes the estimation of soil erosion rates due to surfa...
Production of olive oil is one of the most important activities in the Mediterranean area, particularly in Greece, which holds the third place worldwide after Spain and Italy. For every tone of produced olive oil, about 25% of liquid wastes (olive oil mill wastes- OOMWs) enriched with organic load and inorganic constituents are produced. The OOMWs...
The aim of this study is to estimate flood risk in the Mediterranean island of Crete in Greece, using Geographic Information Systems (GIS). The island of Crete, covering an area of 8265 km2, is one of the most intensively Mediterranean agricultural areas dominated by fruit tree crops. In this study, the factors that are directly related to the crea...
Soil salinisation is one of the major soil degradation threats occurring in Europe. The effects of salinisation can be
observed in numerous vital ecological and non-ecological soil functions. Drivers of salinisation can be detected
both in the natural and man-made environment, with climate and the foreseen climate change also playing an
important r...
The objective of this work is the simulation of the water depth, flow velocity and sediment transport in the downstream part of the Koiliaris River (Crete – Greece). The two-dimensional hydraulic model MIKE 21C is used, which has been developed specifically to simulate 2D flows and morphological changes in rivers. The model is based on an orthogona...
In the present work, the two-dimensional hydraulic models MIKE 21 and MIKE 21C were used in order to simulate the water depth at the downstream section of the Koiliaris River Basin in Crete-Greece. Specifically, an important goal of the present study was the comparison of the widely used MIKE 21 with the MIKE 21C model. The MIKE 21C model has been...
Saltwater intrusion is one of the most important water quality problems in coastal aquifers, especially in areas with increased water demands. Geophysical techniques can provide a non-invasive and cost-effective approach for determining the geometrical characteristics of an aquifer and for guiding the saltwater intrusion modeling process and in tur...
The recent industrial growth together with the urban expansion and intensive agriculture in Greece has increased groundwater contamination in many regions of the country. In order to design successful remediation strategies and protect public health, it is very important to identify those areas that are most vulnerable to groundwater contamination....
Olive cultivation in hot arid areas is hindered by the scarcity of irrigation water. The exploitation of saline water has been proposed as a solution to partially cover plant water demands. This paper presents the effects of salinity [0, 60 and 120 mM sodium chloride (NaCl)] on physiological and reproductive functions of cultivars ‘Koroneiki’ and ‘...
The aim of this work is the development of a decision-making system for an optimal agricultural water management for olive and citrus crops. This decision-making system combines a space-time simulation of an unsaturated flow with the minimum irrigation needs ensuring optimal plant growth. These approaches will be implemented in one of the most inte...
In the present work the MIKE 21C hydraulic model is used to simulate the water depth and flow velocity at the downstream section of the Koiliaris River Basin in Crete-Greece. MIKE 21C is an advanced mathematical modeling system, which has been developed specifically to simulate 2D flow and morphological changes in rivers. The model is based on an o...
Saltwater intrusion is one of the most important water quality problems in coastal aquifers. Effective prediction tools of saltwater intrusion are of vital importance in the prevention of groundwater contamination in these regions. Geophysical techniques constitute non-invasive methods with a twofold purpose: determining the aquifer geometric and g...
The water flow and the mass transport of agrochemicals in the unsaturated and saturated zone were simulated in the extended alluvial basin of Keritis river in Crete, Greece (a predominantly flat and most productive citrus growing area) using the hydrological model MIKE SHE. This model was set up based on information on land use, geology, soil struc...