Issue 2

In this study, ASTER (Advanced Spaceborne Thermal Emission and Reflection Radiometer) stereo
imagery was analysed in combination with Global Positioning System (GPS) data and field observations,
using Geographical Information Systems (GIS) techniques to examine the potential of satellite
remote sensing to support watershed management. Terrain elevation data were derived for the region
of Heraklion, Crete. The accuracy of the ASTER derived DEM (Digital Elevation Model), was better
than 20 meters (planimetric) and better than 15 meters (elevation). Supervised classification techniques
were applied for land cover production using ASTER multi-spectral imagery and filed observations
at predefined application sites. The determination of training areas required in the supervised
classification scheme was based on these observations. Finally, GIS methods were applied to estimate
watershed characterization parameters for the study area offering the advantages of spatial data handling
capabilities and automatic extraction of thematic information. The drainage pattern, which was
derived, provided a generally representative depiction of the watershed. The output pixel spacing of 15
m of the produced DEM as well as the high spatial resolution of ASTER imagery found to be quite satisfactory
for the watershed characterization of the study area, indicating the high potential of ASTER
imagery to support watershed management.

In this paper an Environmental Impact Assessment Multicriteria Decision Analysis System for irrigation
projects (EIAMDAS) used as a comprehensive tool that enables comparison between irrigation
project alternatives is presented. The comparison is based upon all relevant aspects of the surrounding
environment during irrigation systems operation. The decision is case dependent, and relies on the
compromise between positive and negative impacts associated with the project, and the relative importance
(weights) of the different factors involved. Inputs to the EIAMDAS include are information of
the existing system operation derived from selected answers for a set of multiple choice questions that
provide sufficient information to describe the baseline conditions and the general design for several
project alternatives. On the other hand, the EIAMDAS outputs, in the form of positive and negative
scores, allow the user to evaluate different impacts criteria on neighbouring and project areas. The user
is also required to input importance weights to these categories of impacts. The different impacts criteria
are categorised as environmental social and economic impacts using compromise programming.
The final output is an overall environmental index for each project alternative. Two years of real time
control data are used to illustrate system performance. Conclusively the EIAMDAS is an efficient tool
for supporting the decision making process, especially in the trade-off between project alternatives
according to anticipated environmental impacts including economic aspects. Although this EIAMDAS
was developed for irrigation projects applications, the software was designed in a flexible manner to
allow for future adaptation to other applications using the same technique.

An initial GIS data base has been assembled in 2001 covering the various parameters related to the
Nestos river basin and its delta. This data set is being used for water resources modelling purposes within
the frame of the multinational PROMENES initiative. The initial data gathering has produced a vast
set of information which has been stored using the ArcView GIS tool. The European Water
Framework Directive (WFD) recently defined guidelines for structuring the GIS databases aimed at
water resources management. It is stressing the use of "open" GIS systems and formats in order to further
facilitate maintenance and reporting to the public, a needed requirement. The present project
explores the application of the DPISR concept to the publication of a "State of the Environment
Report" on the Nestos delta through Internet. This concept has recently been proposed by the
European Environmental Agency and is already in application for air pollution indicators broadcasting
and urban environmental problems reporting. The PROMENES data base has been restructured using
an "open" GIS approach and lessons learned on how to organize water management related datasets
for the building of environmental indicators. A prototype web site is evaluated and is being tested for
public broadcast under the supervision of EPO Living Lakes, an environment protection organisation
operating in the Nestos delta.

In the context of a research program regarding water quality management and protection plan for Lake
Plastira, one of the main tasks was the establishment of a sound relationship between the minimum
water level and the trophic state of the lake.
The study involves the application of a eutrophication-dissolved oxygen mathematical model
(EUTRO-SEL) which describes various physical, chemical and biological processes taking place in a
water body.
Three water management scenarios were examined in the context of the study, based on alternative
minimal operating water levels (782m, 784m and 786m).
According to the modelling results and the classification of the water bodies according to the recent
standards and trends within the European Commission, the operation of Lake Plastira at a minimum
water level of 786 m ensures very good water quality characteristics (Category I). The operation of the
Lake Plastira at lower water levels between 782-784 m, results in acceptable water quality that classify
the lake into Category II.
Since in all three management scenarios the water quality is acceptable and describes a water body with
at least good water quality, acceptable minimum operational water level, can be determined by other
considerations (e.g. elasticity of demand, lanscape aesthetics, etc).