Συμβολή στην βιώσιμη διαχείριση των υδατικών πόρων της υδρολογικής λεκάνης της λίμνης Τριχωνίδας

Abstract

The integrated and rational management of water resources has become an imperative need nowadays, in order for the increasing water demands to be covered and for the water storages to be maintained in high qualitative and quantitative levels. Problems, such as the decreasing water quality, including salinization and seasonal water deficiency due to the excessive abstractions, can be successfully overcome with the development and application of sustainable management plans on the catchment level. The recent relevant European and National legislation prepare and impose the creation of administrative authorities and integrated water management plans in the next years. For this reason, wide scientific knowledge, detailed hydrologic data, profound study of the water resources per catchment, cooperation between scientists and the responsible management authorities, as well as the appropriate legislative framework and social acceptance are demanded. The specific doctoral thesis aims at the appointment of a methodology for the development of integrated water resources management plans with the use of contemporary techniques, which include the processing of satellite images, the use of hydrologic models, the evaluation of environmental impacts and the application of isotopic methods. The implementation of the aforementioned methodology will be practiced on Trichonis catchment, which is in Western Greece, in the county of Aitolokarnania and hosts one of the biggest natural lakes of the country with a maximum water volume 2,8x106 and mean surface 96km2. Lake Trichonis comprises the main water body of the study area and covers important irrigation needs of the cultivated areas not only within, but also outside the catchment. Specifically, through the controlled flow canal which connects the lakes Trichonis and Lysimachia, big amounts of water are being discharged during the irrigation period for the coverage of the plains of Mesologgi, Katochi and Lesini, whereas during the winter period the water excess flows towards the system of Acheloos river, in order for floods to be avoided. Until today, water management of Trichonis lake did not take into consideration either the available storages or the environmental needs of the area, leading, in this way, to the observation of an important water level decline during the summer period which reaches 60cm, whereas during the winter period the water level rises significantly, thus creating an annual fluctuation of approximately 1m. Also, around Trichonis lake ecologically significant wetlands exist, especially at the southern part of the coastline. They belong to NATURA 2000 environmental protection network and are being protected by National and European legislation. The specific wetlands depend on the existing hydrologic conditions and the high water level fluctuations affect them negatively, leading to the shrinkage of their area in the last years. So, there is an imperative need to develop and apply an integrated water management plan, which will manage the coverage of both human and environmental water needs, while it will take into consideration the available storages, securing long term sufficiency and high water quality..............................................................................................................................................