Issue 3

The political dimension of water becomes highly important not only because of its scarcity, but
also as a result of its sharing across national boundaries. Approximately 40% of the global
population lives in tranboundary water basins, emphasizing the need for cooperation and
harmonization of policies. Hence, the need for “Hydrodiplomacy” rose under the framework of
sustainable development and international cooperation.
Especially in Greece, management of transboundary rivers is of major importance, since
roughly 25% of the country’s renewable resources are “imported” as in four out of the total
five transboundary rivers Greece is the downstream country. The lack of transboundary water
agreements between Greece and its neighboring countries (except with Bulgaria) is affecting
greatly the international cooperation and the status of the water resources. Hence, the
implementation of appropriate methodologies is crucial for the promotion of the integrated
management of these areas. This study refers to five transboundary basins in Northern
Greece and introduces the principles of “Hydrodiplomacy” in their management.

It is difficult for decision-makers to evaluate the impact of their territorial policies. Aspects to
be considered in this evaluation include those relating to humans, environment protection and
industry development. Two reasons explain the difficulty: decision-makers cannot specialise
in all domains implied in the process of decision and there is no simple tool allowing questions
such as “what would happen if…” to be easily answered.
Our work addresses this problem in the domain of water management at a catchment scale
and consists in evaluating water balances. We have developed a software framework
allowing simulation scenarios to be easily run and results about outlet flow and groundwater
variation to be easily interpreted. In this paper, we study anthropogenic scenarios consisting
in modifying the land cover at different scales: parcel, slopes or catchment. The simulation is
supported by a methodology allowing catchment models to be built up using a hierarchical
and modular approach based on components formalised by sequential machines. Few
modelling parameters are necessary because our purpose is not to build up a “perfect” model
to represent a catchment from a hydrological point of view but to illustrate the impact of
climatic changes or anthropogenic activities on water balance. The simulation interface allows
climatic data files to be selected to compare various scenarios. It allows the land-use to be
easily modified to understand the impact of anthropogenic activities on water from a
quantitative point of view. Modelling and results of simulation are illustrated on a catchment
located in the area of Cévennes (South of France).

Agrochemicals, geochemical structure and industrial wastes create a potential source of
heavy metal pollution in the aquatic environment. The porpuse of this study was to investigate
the seasonal variations in five heavy metals (Cu, Zn, Cd, Pb and Cr) in the surface water of
the Keritis river, one of the most important rivers in Chania, Greece. The surface water
samples were colloected at 8 sampling sites in the Keritis river system. Seven sampling
campaigns were carried out in each site in a 1-year period, during August 2004 to July 2005.
Heavy metals were determined by using flame and furnace Atomic Absorption Spectrometry.
Ancillary data included water temperature, pH and electric conductivity.
Significant variations were observed between the warm period (May to September) and the
wet period (October to April), for the studied metals. Heavy metal concentrations were
sufficiently higher in warm period than in wet period. The average concentrations in wet and
warm period were: Cu (0.88 μg l-1; 6.62 μg l-1), Cd (0.005 μg l-1; 0.019 μg l-1), Pb (0.28 μg l-1;
2.59 μg l-1), Cr (1.44 μg l-1; 3.25 μg l-1), and Zn (4 μg l-1; 39 μg l-1), respectively. The relative
variability followed the order: Zn>Pb>Cu>Cd>Cr. The seasonal variations may be due to
either anthropogenic causes, such as agricultural practices, especially the use of fertilizers
and biocides or wastewater discharge, or natural causes, such as water temperature, pH,
redox condition, or river flow. The water pH was lower in warm period than in wet period. The
concentrations of Cu, Zn, Cd, Pb and Cr were found to be positively related to the water pH in
both periods. The water temperature was higher in the warm period and no strong, but
remarkable correlations were found between the heavy metal concentrations and the
temperature values for the warm and the wet period. Also, there was found no correlation
between the heavy metal concentrations and the electrical conductivity.

Nitrate in groundwater in the Gaza Strip, Palestine has become a serious problem in the last
decade. As a result of extensive use of fertilizers, discharging of wastewater from treatment
plants, and leakage of wastewater form cesspools, increased levels of nitrate up to 400 mg/l
have been detected in groundwater. Nitrate concentrations more than 50 mg l-1 are very
harmful to infant, foetuses, and people with health problems. The most efficient way to
prevent nitrate impacts is to identify the sources of nitrate and to reduce them at the source.
In this study, samples of groundwater from 63 wells were collected and chemically analyzed.
Analysis of these samples revealed they have nitrate concentrations more than the maximum
permissible limit recommended by World Health Organization (WHO). The major ion
chemistry analysis was used to identify nitrate sources.
Based on the relation between land use and nitrate concentration in groundwater, sources of
nitrate were identified. These sources are: (1) leakage from wastewater treatment plants, (2)
leakage from cesspits, and (3) intensive agricultural activities. It was found that the leakage of
wastewater from cesspits and over-loaded treatment plants has greater influence on
groundwater nitrate contamination more than agricultural activities. This study shows the
important role of the type of infiltrated water into the sub-soil, combined land use, in
determining the source of nitrate in groundwater.