Nestos River Delta, Greece

Contact the Nestos River Delta study site team

2010-11-25T11:02:06Z

Institute full name:	Democritus University of Thrace
Institute acronym:	DUTH
Institute profile:	DUTH is situated in north-east Greece and has achieved a place among the leading public research universities in Greece. The Laboratory of Engineering Geology has wide research experience in hydrogeological, geotechnical and hydrochemical studies such as: Management of groundwater and surface water, Seawater intrusion in coastal aquifers and soils, and Management of groundwater recharge. Present and previous projects include: Water Reuse (Funding: EU/ INCO-CT05-516731) Artificial recharge using wastewater (Funding: Municipality of N. Peramos, Kavala) Water Repellency (Funded: EU/ FAIR-CT98-4027) Seawater intrusion in coastal aquifers and soils of Thrace, Greece (Funded: Ministry of Agriculture, Prefectures) Groundwater Artificial Recharge for the plain regions of Thrace, Greece (Funded: Ministry of Agriculture) Potable water management (Funded: Municipal Enterprise for Water Supply and Sewage) Water Resources Management in Xanthi, Kavala, Drama, Komotini, Alexandroupoli, Greece (Funded: Individual Prefectures)
Website	http://www.duth.gr/
Address	Democritus University of Thrace Department of Civil Engineering Vas. Sofias 12, PROKAT GR-671 00 Xanthi Greece Fax: +30 25410 79691
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Involved personnel

Name	Contact details	Key qualifications	Photo
Ass. Prof. Dr. Ioannis Diamantis	Tel: +30 25410 79691 E-mail: jdiam@civil.duth.gr	Coordinator of more than 50 national research projects; hydrogeologist, fundamental and applied research related to water management and sea water intrusion.
Ass. Prof. Dr. Fotios Pliakas	Tel: +30 25410 79695 E-mail: fpliakas@civil.duth.gr	Civil Engineer, with scientific interest in groundwater flow modeling, groundwater development and management, management of aquifer recharge and seawater intrusion.
Drs. Apostolos Ziogas	Tel: +30 25410 79692 E-mail: aziogas@acn.gr	Geologist, expert in soil science, soil physical properties, designing and executing field work.
Dr. Vasilios Diamantis	Tel: +30 25410 79692 E-mail: bdiamant@env.duth.gr	Environmental Engineer, specialist in wastewater management, with special interest in water reuse for irrigation. Execution of field and laboratory work.
PhD Candidate, Ioannis Gkiougkis	Tel: +30 25410 79692 E-mail: jgiougis@civil.duth.gr	Geologist, specialist in data monitoring and storage and execution of field trials. Special interest in seawater intrusion, groundwater resources management, hydrogeology of coastal aquifers.
Alexadros Pechtelidis, MSc.	Tel: +30 25410 79692E-mail: apechtel@civil.duth.gr	Environmental Engineer, MSc. Expert in fluid mechanics. Main topics: Field trails, Sample collection, Laboratory measurements.

Study site location & description

2007-11-09T12:47:02Z

The Nestos River Delta study site is located in Eastern Greece, near the coast south of the city of Xanthi, and centred near the village of Maggana.

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During the decades of '50s and '60s, a variety of flood-controlling engineering works have been built in Nestos River Delta plain, in Thrace, Greece, in the framework of the then conceived drainage-system management and wetlands natural protection. These works included river diversion, caisson, modification, draining of coastal wetlands and construction of drainage systems. These interventions have been carried out without any provision for the induced changes in the ecological balance and have changed the groundwater-recharging regime, causing the restriction of the surface water sources recharging groundwater. The aimed enlargement of cultivated lands, on the other hand, resulted in water increasing demand. This fact, in combination with the construction of the interventions mentioned above, brought out phenomena observed, now days, at the eastern part of the Delta, such as groundwater storage decrease, gradual extinction of coastal wetlands, degradation of the related phreatic aquifers and soil salinization. The most affected region is that of Maggana.

More details ... read the full study site description and an overview of all sites
	Read the full study site description
»Comparative overview of all study sites

Stakeholders and their sustainability goals

2011-11-08T14:07:53Z

Study site stakeholder workshops
Farmers and scientists

Stakeholder groups

Region of Eastern Macedonia-Thrace, Department of Water Management, Ministry of the Environment, Physical Planning & Public Works, is a state organization which is related to surface and ground water use, applications and management, including relevant licences.
Prefecture of Xanthi, Administration for Land Reclamation, opines on land works and constructs as well in order to promote agricultural productivity.
Prefecture of Xanthi, Administration for Agriculture.
Topeiros Municipality, municipality located within the study site area.
Democritus University of Thrace, local University among leading in Greece. The School of Engineering is located in Xanthi. It consists of the Departments of Civil, Electrical, Environmental, Mechanical and Architectural Engineering, has wide research experience in hydrogeological, geotechnical and hydrochemical studies such as: Management of groundwater and surface water, seawater intrusion in coastal aquifers, management of groundwater recharge and soil degradation.
Traditional farmers.

Sustainability goals

The sustainability goals identified by expert estimate can be used as a starting point for the local community to develop their own visions and goals for alternation of the ominous ecological future.

Goal 1	Conservation of soils that provide high levels of productivity
Goal 2	Groundwater management in the broader area
Goal 3	Groundwater recharge in order to reverse seawater intrusion phenomenon
Goal 4	Application of suitable cultivations
Goal 5	Surface water management and transport
Goal 6	Conservation of current biological diversity
Goal 7	Remediation and conservation of saline soils
Goal 8	Improvement of local economy
Goal 9	Enforcement of groundwater management laws

Source: expert estimate, study site leader

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»Stakeholders & their sustainability goals - overview

Drivers, policies and laws

2011-11-08T14:14:36Z

The reasons for desertification and land degradation occurring can be environmental (for example due to the climate or soil conditions), economic, due to the actions of people or, most often, due to a combination of factors. The resulting degradation may be temporary or permanent.

To help understand this complex picture it can be helpful to think in terms the dominant socio-economic and environmental forces that are driving the process of land degradation. These place pressures on the land which have particular impacts. Human society may have already made responses to those impacts, or may have knowledge about how they could respond. Decisions about which responses to make may also be governed by a range of international, national or local policy regulations and agreements.

In the Nestos River Delta study site, the same stakeholder workshop and questionnaires that were used to identify existing and potential response strategies (»Identifying strategies: Stakeholder workshop 1) also discussed and identified these driving forces; pressures; impacts; and the policy and regulation environment. This information was then used to inform the choice of »Field experiments and the scenarios used in »Simulated biophysical impact of remediation strategies and their financial viability.

Select main driver

Socio-economic drivers
Environmental drivers
Pressures
Impacts
Responses
Policies

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»Drivers and policy context for all study sites

Gender-related issues

2011-03-03T13:47:21Z

More details ... download the poster
	Gender-related issues: Nestos [71 kB]

Land degradation and conservation maps

2009-06-08T12:55:43Z

The WOCAT tool for mapping land degradation and sustainable land management has been used in the Nestos River Delta study site. Using the tool, an interdisciplinary team of specialists has recorded observations of land degradation, sustainable land management and recommendations for further prevention or mitigation on a land use base map.

Select map type

Comments

Map version: 4Oct11

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»Assessment and mapping methodology; summary results from all study sites

Evaluating the desertification risk assessment tool with local experimental results

2013-09-30T12:13:38Z

Author: Victor Jetten

Introduction
The coastal region of the East Nestos River Delta (Maggana, northern Greece) has limited freshwater supplies although irrigation is exceptionally intensive. Studies show that there is intrusion of seawater into the coastal aquifer. The shallow brackish groundwater is in use for irrigation since the last 40-50 years, which has caused severe salinization of the soil. Apart from the chemical problems for crop growth, salinization affects the permeability of soil and causes infiltration problems, because sodium in the groundwater replaces calcium and magnesium adsorbed on the soil clays and causes dispersion of soil particles: a breakdown of aggregates and natural soils structure. Also deeper in the soil this has caused compacted layers to form. Salinization is very difficult to reverse, and the only possible solution in the area lies in flushing the soil with fresh water from the river systems or fresh groundwater further inland. This experiment tests the soil degradation can be reversed on a field scale and if this results in better crop performance.

Desertification indices
The desertification indicator in this area is salinization. None of the others apply. When filling in the area characteristics the salinization aspect turns out to be moderate/high (2.99). This is mainly due to the factor “exploitation of the groundwater”. When this is high (over-exploitation) the salinization risk is medium to high, when there is no exploitation this is lowers the risk to “no risk”. This factor and the factor “population density” seem to be the only ones correlated to salinization risk in the system. This means that the technology (fresh water irrigation) gives a lowering of the salinization risk because the assumption is that this will decrease groundwater exploitation and even groundwater recharge (risk index = 0.75).

Cereals/vegetables salinization risk with groundwater exploitation (unmitigated circumstances)

Conclusions
The indicator tool correctly identifies the area as having a high salinization risk but this depends only on one factor: groundwater exploitation. Thus different technologies that influence this factor will have an immediate effect, others (such as applying chemicals) will not have an effect.

More details ... general conclusions and results from other study sites

»Evaluating the Desertification Risk Assessment Tool with experimental results

Identifying strategies: Stakeholder Workshop 1

2008-11-03T12:48:19Z

A report on the results of the workshop "Land degradation and desertification - existing and potential prevention and conservation strategies" held in Erasmio, Prefecture of Xanthi, Greece, 19 December 2007
Workshop moderators: Prof. Dr. I. Diamantis, Prof. Dr. Ir. F. Pliakas

Overall aim of the workshop was to present traditional methods to combat soil salinization.
Specific objectives included:

Exchange experiences between researchers, farmers and stakeholders

Presentation of the scientific terminology to farmers and stakeholders

Development of confidence and cooperation between farmers, researchers and stakeholders

Identification of reclamation methods

Selection of the most promising methods for field evaluation

Background
One of the most important environmental problems of the study area is the phenomenon of seawater intrusion into the coastal unconfined aquifer of eastern Nestos Delta, as a result of a combination of anthropogenic activities with negative impacts on the hydrologic and hydrogeologic regime of the entire area. The main activities mentioned before are the drainage of coastal areas in order to provide areas for agricultural development, the channelization and alignment of Nestos River and finally the extensive overpumping of the phreatic aquifer for irrigation purposes (a practice which takes place continuously up to date).

Main causes and effects of land degradation identified in the workshop

Effect of irrigation water quality	Continuous irrigation with poor quality water for approximately 20-30 years has resulted in the formation of saline and sodic soils with distinct physical and chemical characteristics. Poor drainage and formation of impermeable clay layer has been observed in several soils in the study site.
Effect of climatic conditions	Decreasing rainfall results in poor salt leaching from the soil profile and recharge of groundwater.
Effect of shallow groundwater table	This is the cause of salinization for soils situated in the low lying regions adjacent to the coast. In this region, the groundwater is saline less than 1 m from soil surface, which results in continuous accumulation of soluble salts in the surface soil due to evaporation. Many hectares of land in the coastal low lying regions consist of natural saline soils and salt marshes.

Solutions already applied at the local level

Use of freshwater	Farmers pump water from adjacent streams and transport it several km through private networks. Local authorities permits farmers to use surface water for irrigation but do not allow them to open new wells, especially in the areas where excessive deterioration of groundwater quality occurs. However, farmer are still make use of groundwater for irrigation.
Use of gypsum	Some farmers have used gypsum to improve salinity problems. Gypsum application lacks scientific background and verification.
Use of press mud	This material is a by-product of sugar processing. It has been applied in the past for soil improvement but proved not to be adequate for sodic soils.
Use of winter rainfall	Winter rainfall can be used both as a management tool to temporarily improve surface soil quality (for the proceeding summer cultivation period) and to cultivate winter crops. Winter rainfall can be managed in addition with gypsum application. Since freshwater is scarce in the region, winter crops cultivation is performed in several cases.
Drainage improvement	The local authorities often perform maintenance work for the surficial drainage systems of the area, including digging and weed removal.
Soil internal drainage	Several farmers applied deep tillage for drainage improvement. However, this is accomplished without scientific support and as a consequence an undesirable hardpan layers is formed again.
Seeding placement	The placement of seeds is especially important since salts accumulated in the ridge area.

Strategies to be evaluated

1. Freshwater transport
2. Deep ploughing (soil internal drainage improvement)
3. Drainage system maintenance (groundwater level control)
4. Gypsum addition

Draft outline of strateby for sustainable land management in this region

A sustainable land management strategy in the study region consists of:
1. Transportation of freshwater (construction of large distribution network)

2. Drainage improvement (new drainage canals and maintenance of existing)
3. Reclamation of degraded land

Internal drainage improvement (deep ploughing, installation of perforated pipes or ditches)
Removal of exchangeable sodium (gypsum addition)
Salt leaching (freshwater flushing)

In cases where freshwater transportation is not possible:
1. Use of winter crops (winter wheat)
2. Use of gypsum to improve soil quality in combination with winter rainfall
3. Irrigation control and timing
4. Soil moisture content and soil salinity monitoring and control by irrigation (Maintenance of soil moisture and salt content at optimum level by using appropriate monitoring equipment)

More details ... download the full report and poster and see results and general conclusions from other study sites
	WP3.1 Stakeholder Workshop 1: Maggana (report) 505.51 kB
»Identifying strategies: Stakeholder Workshop 1 methodology and summary results from all study sites

Evaluating strategies: technologies and approaches documented

2011-02-22T13:17:58Z

Stakeholder Workshop 1 identified a number of existing or potential strategies to combat desertification and land degradation in the Nestos River Delta study site. In the months following the workshop these strategies (technologies or approaches) were documented and evaluated in a structured and standardised way and their descriptions were entered in the WOCAT Technologies and Approaches databases in order to share the information with other DESIRE sites as well as globally.

For details of all Technologies and Approaches documented in the WOCAT Database (from the DESIRE study sites and from other sites worldwide), see

For those relating to this study site, click on the Name of technology or Name of approach to go directly to the descriptions in the database.

WOCAT Technologies Database

Country	Code	Name of technology	Author
Greece	GRE05	»Transport of freshwater from local streams	Diamantis Vasileios, Democritus University of Thrace

WOCAT Approaches Database

Country	Code	Name of approach	Author
Greece	GRE05	»Combating soil salinization	Giougis Ioannis, Democritus University of Thrace

Selecting strategies: Stakeholder Workshop 2

2009-05-21T17:17:11Z

Results and conclusions from Stakeholder Workshop 2 "Selection and decision on technologies/approaches to be implemented", held in East Nestos Delta Basin, Greece October 15th, 2008.

Authors: V. Diamantis, I. Gkiougkis, A. Pechtelidis

The workshop methodology was designed and coordinated through Research Theme 3: Potential prevention & mitigation strategies and consisted of three main elements:

A participatory approach to guide and lead the workshop participants through a process of multi-criteria evaluation of different options which finally results in decision-making on strategies to be field-tested.
The WOCAT database containing locally applied options as well as options from a number of other contexts.
'Facilitator', a Multi Objective Decision Support System (MODSS) software to support the single steps of the evaluation and decision-making process.

Target groups were the same as in the 1st workshop: local stakeholders (land users, representatives of local authorities, local NGOs) and external stakeholders (researchers, development professionals, NGOs, GOs).

As a result of the workshop, the following measures were selected for testing in field experiments.

Measures	Specifications	Type	Land use
Transport of freshwater from local streams	Instead of saline groundwater	management	cropland

More details ... download the full report and see general results and conclusions from other study sites
	WP3.3 Stakeholder Workshop2: Maggana, Greece (report) (0.8 MB)
»Selecting strategies: Stakeholder Workshop 2 methodology and summary results from all study sites