Υδρογεωλογικό καθεστώς πεδιάδας Φαιστού-Τυμπακίου με έμφαση στην ποιότητα των υπογείων νερών

Παρασκάκη, Δανάη Ν.; Paraskaki, Danai N.

dc.contributor.author	Παρασκάκη, Δανάη Ν.	el
dc.contributor.author	Paraskaki, Danai N.	en
dc.date.accessioned	2015-03-17T10:51:29Z
dc.date.available	2015-03-17T10:51:29Z
dc.date.issued	2015-03-17
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/40433
dc.identifier.uri	http://dx.doi.org/10.26240/heal.ntua.4241
dc.description	Εθνικό Μετσόβιο Πολυτεχνείο--Μεταπτυχιακή Εργασία. Διεπιστημονικό-Διατμηματικό Πρόγραμμα Μεταπτυχιακών Σπουδών (Δ.Π.Μ.Σ.) “Επιστήμη και Τεχνολογία Υδατικών Πόρων”	el
dc.rights	Αναφορά Δημιουργού-Μη Εμπορική Χρήση-Όχι Παράγωγα Έργα 3.0 Ελλάδα	*
dc.rights.uri	http://creativecommons.org/licenses/by-nc-nd/3.0/gr/	*
dc.subject	Υπόγειο νερό	el
dc.subject	Υδροχημεία	el
dc.subject	Τυμπάκι	el
dc.subject	Δειγματοληψία	el
dc.subject	Χημικές αναλύσεις	el
dc.subject	Groundwater	en
dc.subject	Hydrochemistry	en
dc.subject	Tympaki	en
dc.subject	Sampling	en
dc.subject	Chemical analysis	en
dc.title	Υδρογεωλογικό καθεστώς πεδιάδας Φαιστού-Τυμπακίου με έμφαση στην ποιότητα των υπογείων νερών	el
dc.title	Hydrogeological regime of plain Festos-Tympaki with emphasis on quality of groundwater	en
dc.contributor.department	Υδατικών Πόρων και Περιβάλλοντος	el
heal.type	masterThesis
heal.classification	ΔΙΑΧΕΙΡΙΣΗ ΥΔΑΤΙΚΩΝ ΠΟΡΩΝ	el
heal.classification	WATER RESOURCES MANAGEMENT	en
heal.classificationURI	http://localhost:8080/healp/data/8/8/10
heal.classificationURI	http://localhost:8080/healp/data/8/8/10
heal.language	el
heal.access	free
heal.recordProvider	ntua	el
heal.publicationDate	2014-10-16
heal.abstract	Αντικείμενο της παρούσας εργασίας είναι η διερεύνηση του καθεστώτος των υπόγειων υδάτων στην πεδιάδα Φαιστού-Τυμπακίου, με έμφαση στην ποιότητα τους. Η εργασία περιλαμβάνει βιβλιογραφική επισκόπηση και μελέτη της ποιότητας των υπογείων νερών στα πλαίσια της παρούσας, με δειγματοληψία από γεωτρήσεις, χημικές αναλύσεις και αξιολόγηση των νέων δεδομένων. Αρχικά γίνεται μια περιγραφή της Κρήτης, της γεωλογίας, κλίματος, λεκάνων απορροής κτλ και στη συνέχεια η μελέτη αφορά συγκεκριμένα την πεδιάδα της Δυτικής Μεσσαράς και ιδιαίτερα τον κάμπο Φαιστού-Τυμπακίου, με αναφορά στο γεωλογικό και υδρογεωλογικό καθεστώς , το κλίμα, το υδρολογικό ισοζύγιο, την υδροχημεία κτλ. Έγινε η συλλογή υφιστάμενων στοιχείων για την περιοχή (χάρτες, σχέδια, µελέτες, στοιχεία ποιότητας, µετρήσεις παροχών, ισχύουσα νοµοθεσία) από διάφορους φορείς και στη συνέχεια λήφθηκαν δείγματα υπογείου νερού με τη βοήθεια του ΤΟΕΒ Τυμπακίου. Ακολούθησε η χημική τους ανάλυση, η ανάλυση των αποτελεσμάτων και η δημιουργία υδροχημικών χαρτών για την εξαγωγή συμπερασμάτων για την ποιότητα του υπογείου νερού και την καταλληλότητα του για διάφορες χρήσεις. Χρησιμοποιήθηκαν το λογισμικό γεωπληροφορικής arcGIS και το λογισμικό Surfer 11, για τη σχεδίαση ισοπαραμετρικών καμπυλών με σκοπό τη δημιουργία των θεματικών υδροχημικών χαρτών. Επίσης, με τη βοήθεια του Aquachem κατασκευάστηκαν τα υδροχημικά διαγράμματα Durov, Piper, Schoeller, Ludwig-Langelier και Wilcox, για την κατηγοριοποίηση του νερού. Η αξιολόγηση και τα συμπεράσματα των χημικών αναλύσεων οδήγησαν στην παράθεση στοιχείων ποιοτικής υποβάθμισης του υπόγειου νερού του κάμπου Τυμπακίου-Φαιστού και διατύπωση προτάσεων σε μια προσπάθεια βελτίωσης της υπάρχουσας κατάστασης στην περιοχή.	el
heal.abstract	With two thirds of the earth's surface covered by water and the human body consisting of 75 percent of it, it is evidently clear that water is one of the prime elements responsible for life on earth. Water quality is defined in terms of the chemical, physical, and biological content of water. The water quality of rivers and lakes changes with the seasons and geographic areas, even when there is no pollution present. There is no single measure that constitutes good water quality. For instance, water suitable for drinking can be used for irrigation, but water used for irrigation may not meet drinking water guidelines. Water quality guidelines provide basic scientific information about water quality parameters and ecologically relevant toxicological threshold values to protect specific water uses. Many factors affect water quality such as: Sedimentation, Runoff, Erosion, Dissolved oxygen, Temperature, Decayed organic materials, Pesticides, Toxic and hazardous substances from Industries, Oils, grease, and other chemicals, Detergents, Litter and rubbish, Sewage, wastewater produced from houses, schools, hospitals, workshops, laboratories, etc., Agricultural wastewater from fertilizer and pesticides, Liquid waste from small or large animal farms, Acid rain, carrying atmospheric pollutants in groundwater due to infiltration Water’s protection from these factors that degrade its quality and management is very important for the preservation of life. Study area: Tympaki This post-graduate project refers to the chemical features and quality of the ground water in Tympaki of Messara, in Crete. Messara located in the southern part of Heraklion and comprises of a plain with east-west orientation, about 25 km long and 5 km wide, with a total area of 112 km2 The valley is protected from wild Asterousia Mountains, while the western side ends in a huge coastline. Messara is crossed by rivers Koutsoulidi and Geropotamos. Geropotamos river covers an area of 600.6 km2 and his main tributaries are Koutsoulidis river (121, 9 km2) and Lethaeos river (43, 4 km2). The plain of Messara is comprised of 45% quaternary sediments, while the surrounding mountains and hills of 53% of Neogene sediments and flysch, with a relatively large amount of surface runoff. There is a 2% of karst formations, which is, due to the permeability of rocks, characterized by a negligible amount of surface runoff. The central part of the basin (study area) Tympaki, is covered by Pleistocene deposits (conglomerates, sands, marls, sandstones, clays and limestones). In addition, we meet clastic sedimentary rocks in the greater area, of the Quaternary Period (marine and terrestrial deposits). Tympaki is one of the most important agricultural areas of Crete. Farming, mainly greenhouses, citrus and olive groves are the main human activities in Tympaki, resulting to widely developed irrigation systems. Excessive water pumping from underground aquifers, in order to cover the needs of water supply and irrigation, as well as the constant use of pesticides and fertilizers lead to the degradation of water quality. The need to increase the productive potential of the economy led to bigger agricultural production to such an extent that there is a significant increase of nitrates in groundwater. Also, a large number of illegal drillings is detected in the area causing humiliation of the underground aquifer’s level and increasing the risk of appearance of salinization. The irrigated area is 40,000 acres and the total irrigation water used today comes from the underground potential. The alluvial-Pleistocene aquifer that occupies the coastal-central part of the basin, has an area of approximately 50 Km2 and receives an average rainfall of less than 500 mm. Due to Tympaki’s climate the area is suitable for the development of many green houses for early season vegetables. The climate is temperate-marine dry-warm with long summers and mild-warm with short winters. Chemical analysis In order to determine and analyze the water quality of the study area, quality data were gathered from I.G.M.E. for the years 2004 to 2008 and samples were taken directly from drills in May of 2014. The chemical analysis methods used were: Ionic ratios, Hydrochemical maps, Hydrochemical diagrams (Durov, Piper, Ludwig Langelier, Wilcox, Schoeller) Comments In the Tympaki area we observe a slight increase to the values of nitrates compared to the standards of legislation. This is due to the use of nitrogen fertilizers and pesticides on crops. The problem is deteriorated by livestock waste and the operation of olive mills in the area. Conductivity presented elevated values in this study. This indicates the risk of seawater’s intrusion in the aquifer, due to overpumping (legal or not), in order to irrigate crops. The construction of Faneromeni’s dam causes reduction of the aquifer’s recharge rate, due to decrease of the amount of runoff which results to Koutsoulidis river, contributing to the general lowering of the aquifer’s level. Also, in several wells high values of SO4 ions were detected. This may be caused by natural causes, such us the existence of Gypsum in Neogene deposits and the geological formations of the Pindos zone. Chlorides are slightly increased, but they appear values lower than 250 mg/l, which is the limit according to legislation. These values are because of the composition of Tympaki’s bedrock, which consists of sedimentary formations and also due to the penetration of sea water in the aquifer. The over-pumping of underground water for covering irrigation needs, and the construction of wells without permission, in combination with the lack of rain for years 2004-2008, intensify the problem, making it difficult to replenish the aquifer to its original levels. Unfortunately Faneromeni’s dam contributes to this difficulty and natural recharge of the aquifer. The dam’s core is earthen clay with a maximum height of 75m and the foundation crest width 8m. The annual amount of water in the dam is 19.76 • 106 m3. The construction was completed in April 2005 and since then it operates normally. It is estimated that the dam binds more than 1.2 • 106 m3 of water per year. However, since Koutsoulidis river has dried up the recharge of the aquifer was decreased by 11%. The decrescent water level shown in many drillings can allow the penetration of seawater into the aquifer, where geological formations allow it, resulting in deterioration of groundwater quality. In May 2014 water-samples were collected from 7 different drilling positions, in order to understand and estimate the quality of Tympaki’s water. Maps were created using arcGIS program. The maps present the results of chemical analysis in conductivity, NO3, SO4 and Cl- for Tympaki area. Results: The values of conductivity (EC) in the study area, resulting from the water samples analysis, varied from 591 to 1132 μS/cm. All wells exceeded the indicative level of 400μS/cm, and were particularly high at drillings A1 and Soumpalousa. The increased rates in groundwater’s conductivity may be caused by the effect of salinity, geological recommendation or by pollutants and salts from irrigation water from the surface. Chlorides values were estimated from 45 to 129 mg/l, values that exceeded the indicative level of 25 mg/l. These values may be due to penetration of sea water into the aquifer or surface water from irrigation sources, which are contaminated with salts and other elements. Another cause may be the geological background of the area (sedimentary rocks). Nitrates (NO3) ranged from 19.7 to 146 mg/l and are quite beyond the indicative level of 25 mg/l. These values of NO3, which are in some cases higher from the maximum limit of 50 mg/l, suggests the problem of groundwater pollution by nitrates caused by agricultural activities, fertilizers, pesticides, from farms in the region and oil production. SO4 in underground water ranged from 12.6 to 124 mg/l. The values at drilling positions A1, A2, A3, A7 and Soumpalousa exceeded the indicative level of 25 mg/l but did not exceed the maximum permissible limit (250 mg/l). Conclusions The plain Tympaki is one of the most important agricultural areas of Crete with cultivations of early vegetables in greenhouses and olive trees, in a total area of 40,000 acres. The over-pumping of the aquifer in the study area, which is developed by Neogene and Quaternary formations, evokes the risk of entrance of sea water in the aquifer and in combination with systemic-fertilization of crops, causes degradation of water quality in the region. The water samples analysis for the years 2004-2008 indicates a significant lowering of the level of the aquifer, which is due to over-pumping, the creation of many public and private boreholes and wells, sometimes without permission, and the construction of Faneromeni’s dam, which dried up Koutsoulidi river. The results of I.G.M.E. analysis in Tympaki area compared with the results of samples taken in May 2014 show is a significant increase of nitrates which often exceed the maximum permissible value of 50 mg/l set by the legislation. Tympaki region supports the local economy mainly with agricultural activities, the cultivation of early vegetables in greenhouses and olive trees. In the area there are hundreds of acres of crops. As a result the irrigation water requirement is constantly increased and the degradation of the quality of ground water from the use of nitrogen fertilizers and pesticides in the fields is important. Suggestions To improve the quality of ground water in Tympaki area actions should take place, such as: Artificial recharge of the aquifer with water of at least third degree wastewater treatment. In order to do so, it is important to inform the citizens properly and supervise the wastewater treatment thoroughly. Also important is the inspection and maintenance of distribution systems to avoid leaks that lead to unnecessary consumption of water. Carrying out examination for illegal drilling in Tympaki, which creates a risk of further humiliation of groundwater level and seawater intrusion in the aquifer. Controlling livestock waste disposal. Encouraging olive mill waste treatment and proper disposal. Improving sewage system. It is estimated that Faneromeni’s dam bind more than 1.2 Mm3 of water per year and its operation leads to drying up Koutsoulidis river and decrease the recharge of aquifer by 11%. Also, the reduced rainfall, combined with poor snowfall, affect the dam’s water feeding. Thereby, a solution to the problem could be the diversion of river Platy in order to bring around 10 million cubic meters of water in the dam and solve the irrigation problem throughout Messara.	en
heal.advisorName	Κουμαντάκης, Ιωάννης	el
heal.advisorName	Koumantakis, Ioannis	en
heal.committeeMemberName	Κουμαντάκης, Ιωάννης	el
heal.committeeMemberName	Γιακουμάκης, Σπυρίδων	el
heal.committeeMemberName	Καλλιώρας, Αντρέας	el
heal.academicPublisher	Εθνικό Μετσόβιο Πολυτεχνείο. Σχολή Πολιτικών Μηχανικών	el
heal.academicPublisherID	ntua
heal.numberOfPages	150 σ.	el
heal.fullTextAvailability	true