C.1. Theodossiou, N., P. Latinopoulos, and I. Mylopoulos, Quality management of water resources systems using linear and nonlinear programming, Proc. II Conf. Environmental Science and Technology, Molyvos, Mytilini, 482-490, 1991.

C.2. Mylopoulos, I., P. Latinopoulos, and N. Theodossiou, A combined use of simulation and optimization techniques in the solution of aquifer restoration problems, In: Water Pollution, Measuring and Prediction, L.C. Wrobel and C.A. Brebbia, (Eds.), Proc. First Inter. Conference on Water Pollution, Southampton, 59-72, 1991.

C.3. Theodossiou, N., and D. Tolikas, Evaluation of the information in the observation network of the Kokkinohoria aquifer in Cyprus, Proc. 5th National Conference E.Y.E., 287-294, Larissa, 1992.

C.4. Latinopoulos, P., N. Theodossiou, and A. Xefteris, Application of geostatistical methods in quality and quantity aquifer management problems, 2nd National Hydrogeological Conference, Patra, 1993.

C.5. Theodossiou, N., Combined use of simulation and optimization models in aquifer management. A case study, In : “HYDROSOFT 94”,  W.R. Blain, K.L. Katsifarakis (Eds.), 5th International Conference on Hydraulic Engineering Software, 73-80, Porto Carras, Greece, 1994.

C.6. Theodossiou, N., and D. Tolikas, Application of nonlinear programming techniques in the optimization of the function of groundwater systems. A case study, 6th National Conference E.Y.E., 142-148, Thessaloniki, 1995.

C.7. Theodossiou, N., and D. Tolikas, Simulation and optimization modeling in aquifer management. Application in the Kokkinohoria aquifer in Cyprus,  E.W.R.A. 95, Water resources management in the Mediterranean under drought or water shortage conditions, 179-184, Cyprus, 1995.

C.8. Theodossiou, N., Y. Mylopoulos, and P. Latinopoulos, An application of quality management models in the solution of aquifer restoration problems, E.W.R.A. 95, Water resources management in the Mediterranean under drought or water shortage conditions, 223-229, Cyprus, 1995.

C.9. Fotopoulou, E., N. Theodossiou, and D. Tolikas, Application of optimization methods to the problem of excavation de-watering, 6th National Conference E.Y.E., 149-155, Thessaloniki, 1995.

C.10. Theodossiou, N., Application of flow simulation models in the prediction of aquifer development, International Conference on Protection and restoration of the Environment III, 19-26, Chania, 1996.

C.11. Latinopoulos, P., A. Xefteris, P. Anastasiadis, and N. Theodossiou, Application of modeling techniques in a groundwater nitrate pollution problem, «HYDROSOFT 96», 6th International Conference on Hydraulic Engineering Software, 101-110, Penang, Malaysia, 1996.

C.12. Theodossiou, N., Groundwater resources management models. Capabilities and constrains, International Conf. Water Resources Management, Techn. Chamber of Greece, Larissa, 1996.

C.13. Latinopoulos, P., N. Theodossiou, N. Papacharisis and E. Fotopoulou, Investigation of the water resources of the Sithonia peninsula in Chalkidiki, 7th National Conference E.Y.E., 105-112, Patra, 1997.

C.14. Latinopoulos, P, and N. Theodossiou, Water resources quantity and quality investigations in Halkidiki Peninsula, International Conference on Prediction and Restoration of the Environment IV, 69-75, Sani Halkidiki, 1998.

C.15. Katsifarakis, K.L., N. Theodossiou, N, and P. Latinopoulos, Combined use of genetic algorithms and boundary elements in aquifer restoration problems, Hydraulic Engineering Software VII, W.R. Blain (editor), WIT Press, 469-478, Como Italy, 1998.

C.16. Fotopoulou, E., P. Latinopoulos and N. Theodossiou, Determination of well protection areas, 8th National Conference E.Y.E., 393-399, Athens, 2000.

C.17. Latinopoulos, P., N. Theodossiou, Z. Mallios, E. Fotopoulou and A. Xefteris, Water resources investigation in the Upper Anthemountas basin in Chalkidiki, International Conference on Prediction and Restoration of the Environment V, 83-90, Thassos, 2000.

C.18. Theodossiou, N., Use of the Internet in the environmental education of Civil Engineers, International Conference on Prediction and Restoration of the Environment V, 1221-1226, Thassos, 2000.

C.19. Latinopoulos, P., N. Theodossiou, Z. Mallios, A. Xefteris and E. Fotopoulou, Water resources management in the Upper Anthemountas basin in Chalkidiki, 1^st International Conference on Ecological Protection of the Planet Earth,  25-32, Xanthi 2001.

C.20. Theodossiou, Ν., P. Latinopoulos and E. Fotopoulou, Estimation of wellhead protection areas under conditions of uncertainty, International Conference on Protection and Restoration of the Environment VI,  49 – 56, Skiathos 2002.

C.21. Latinopoulos, P., N. Theodossiou, A. Papageorgiou, A. Xefteris and Z. Mallios, Investigation of the water resources in the greater area of the municipality of Moudania, 9th National Conference E.Y.E, 401-408, Thessaloniki 2003

C.22. Latinopoulos, P, N. Theodossiou, Z. Mallios, A. Papageorgiou and A. Xefteris, GIS-based integrated water resources management in the greater area of the municipality of Moudania, International Conference on Protection and Restoration of the Environment VII,  Mykonos 2004.

C.23. Theodossiou, Ν. and P. Latinopoulos, Water resources management in the context of time and space variability, International Conference on Protection and Restoration of the Environment VII,  Mykonos 2004.

C.24. Latinopoulos, P., N. Theodossiou. A. Xefteris, Z. Mallios, A. Papageorgiou and E. Fotopoulou, Integrated water resources management in basins of the prefecture of Chalkdiki, 5^th National Conference of EEDYP, 111-118, Xanthi 2005.

C.25. Theodossiou, N., P. Latinopoulos and E. Fotopoulou, Application of Monte Carlo analysis in the delineation of well head protection areas, 9^th International Conference on Environmental Science and Technology, 1453-1458, Rhodes Island, 2005.

C.26. Theodossiou, N., P. Latinopoulos, G.P. Karatzas and E.A. Maria, Delineation of capture zones in groundwater aquifers as a tool for the application of the “polluter-pays” principle, International Conference on Protection and Restoration of the Environment VIII, Chania, 2006.

C.27. Theodossiou, N. And E. Fotopoulou, Delineation of well head protection zones under real flow field conditions, 10^th National conference E.Y.E., 421-428, Xanthi 2006.

C.28. Theodossiou, N. , P. Latinopoulos, G. Karatzas and E. Maria, Application of the “polluter-pays” principle in groundwater resources under conditions of uncertainty, 6^th National Conference of EEDYP Overall water resources management on a water basin scale, 223-230, Xanthi, 2007.

C.29. Mitsios, P., Tsilonis, G. and N. Theodossiou, Use of simulation models in the protection of groundwater aquifer systems. Application at the upper Anthemountas basin in Chalkidiki, Greece, International Conference on Protection and Restoration of the Environment IX, Kefalonia, 2008.

C.30. Chatziparadeisi, K. And N. Theodossiou, Water balance estimation under climate change conditions: Application on the water basin of Moudania, Chalkidiki, Joint conference: 11^th Hellenic Hydrotechnical Association – 7^th Greek association for water resources management, 19-26, Volos 2009.

C.31. Mitsios, P., P. Latinopoulos and N. Theodossiou, Cost analysis methodology indealing with possible groundwater pollution related problems, Joint conference: 11th Hellenic Hydrotechnical Association – 7th Greek association for water resources management, 83-90, Volos 2009.

C.32. Theodossiou, N and D. Latinopoulos, Economic aspects of the delineation of well head protection areas under conditions of uncertainty, 2^nd Intern. Conf. on Environmental Management, Engineering, Planning and Economics, 309-314, Mykonos 2009

C.33. Theodossiou, N. And E. Fotopoulou, Delineation of well head protection areas using stochastic analysis approach, 11th International Conference on Environmental Science and Technology, 1440-1447, Chania 2009.

C.34. Chatziparadeisi, K., Tolika, K and N. Theodossiou, Climate change impacts on the water balance of small scale water basins, 6^th national conference of the Agricultural Engineers Association, 171-178, Thessaloniki, Greece.

C.35. Kougias, I. and N. Theodossiou, A new music-inspired harmony based optimization algorithm. Theory and applications, International Conference on Protection and Restoration of the Environment X,  Corfu, 2010.

C.36. Kougias, I. and N. Theodossiou, A new music-inspired harmony based optimization algorithm. Application in water resources management problems, International Conference on Protection and Restoration of the Environment X, Corfu, 2010.

C.37. Papapetrou, M. and N. Theodossiou, Stochastic analysis of the geological structure of groundwater aquifers, International Conference on Protection and Restoration of the Environment X,  Corfu, 2010.

C.38. Kougias, I., and N. Theodossiou, Optimization of multi-reservoir management using Harmony Search Algorithm (HAS), 3^rd Intern. Conf. on Environmental Management, Engineering, Planning and Economics, Skiathos, 2011

C.39. Triantafyllou, V., D. Botsis, and N. Theodossiou, Application of Artificial Neural Networks in the investigation of the relationship between rainfall and runoff, 3^rd Intern. Conf. on Environmental Management, Engineering, Planning and Economics, 233-238, Skiathos, 2011

C.40. Theodossiou, N., Kougias, I., Kakoudakis, K. and K. Doikos, Harmony Search Algorithm, a novel optimization technique. Parameter calibration and applications on water resources management problems, 3^rd Intern. Conf. on Environmental Management, Engineering, Planning and Economics, 245-250, Skiathos, 2011

C.41. Vratskidou, C. and N. Theodossiou, Impact of parameter uncertainty on the transport of complex contaminants in aquifers, International Conference on Protection and Restoration of the Environment XI, Thessaloniki, 2012.

C.42. Papapetrou, M. and N. Theodossiou, A methodology for the stochastic approach of the geological structure of groundwater aquifers. Application to an aquifer in northern Greece, International Conference on Protection and Restoration of the Environment XI,  Thessaloniki, 2012.

C.43. Terelidis, A. and N. Theodossiou, Uncertainty analysis of the geological structure of aquifers. Application on the aquifer of Mouriki in Western Macedonia, International Conference on Protection and Restoration of the Environment XI,  Thessaloniki, 2012.

C.44. Dota, A and N. Theodossiou, Water footprint – a new approach in water resources management. Application in the prefecture of Karditsa, International Conference on Protection and Restoration of the Environment XI,  Thessaloniki, 2012.

C.45. Kougias, I, L. Katsifarakis and N. Theodossiou, A novel multiobjective optimization algorithm, MO-HAS. Application on a water resources management problem, International Conference on Protection and Restoration of the Environment XI,  Thessaloniki, 2012.

C.46. Kougias, I, Th. Patsialis, A. Zafirakou and N. Theodossiou, Exploring the potential of micro hydropower systems in urban water supply systems. Decision-making and optimum management using harmony search, 8th International Conference of European Water Resources Association, pp. 447-457, Porto, 2013.

C.47. Vogiatzis, P, K. Petrou and N. Theodossiou, Stochastic simulation of safe water pumping from a potentially polluted aquifer, 4th International Conference on Environmental Management, Planning and Economics (CEMEPE), 2013.

C.48. Siarkos, I, D. Kouvaritaki, A. Charcharidou, and N. Theodossiou, Modelling the effects of agricultural activities on groundwater quality in the aquifer of N. Moudania, Greece, 13th International Conference on Environmental Science and Technology (CEST), 2013.

C.49. Matzari C., Vogiatzis P., Tziritis E., Tzamos E., Fytianos K., Theodosiou N., Kantiranis N. and Filippidis A., Tracing and variability of nitrogenous compounds in the potable water reserves of municipality of Thermi area (C. Macedonia, Greece), 5th Environmental Conference of Macedonia, Thessaloniki, 2014.

C.50. Lazaridou, Ou, P. Nanou, St. Styliadou and N. Theodossiou, Investigation of the potential exploitation of the aquifer of the Aristotle University of Thessaloniki, 10th International Hydrogeological Congress of Greece, Thessaloniki, 2014

C.51. Sevastas, S., I. Siarkos, N Theodossiou and I Yfantis, Simulating groundwater flow in the upper Anthemountas basin in Chalkidiki applying ModFlow and Geographic Information System, 10th International Hydrogeological Congress of Greece, Thessaloniki, 2014

C.52. Terelidis, A and N. Theodossiou, Development of a flow simulation mathematical model, using the “MIKE SHE” program. Application on the aquifer of Moudania, Chalkidiki, 10^th International Hydrogeological Congress of Greece, Thessaloniki, 2014

C.53. Yannopoulos, S.I., G. Lyberatos, A.N. Angelakis, and N. Theodossiou, Evolution of water pumps through the centuries with emphasis on Hellenic Civilizations, IWA Regional Symposium on Water, Wastewater, and Environment: Traditions and Culture, Patras, 2014.

C.54. Theodossiou, N., D. Karakatsanis, and I Kougias, The history of optimization. Applications in water resources management, IWA Regional Symposium on Water, Wastewater, and Environment: Traditions and Culture, Patras, 2014.

C.55. Kougias, I., D. Karakatsanis, A. Malatras, and N. Theodossiou, Developing a harmony-based optimization toolbox: Application on renewable energy production, OPT-i, International conference on engineering and applied sciences optimization, Kos island, 2014.

C.56. Agorastou, E., Lorena S. and Theodossiou, N., Optimal development of a groundwater geothermal aquifer with the application of the Harmony Search Algorithm, International Conference on Protection and Restoration of the Environment XII, Skiathos, 2014.

C.57. Kasapaki, M., Nisotaki, M. and Theodossiou, N., Application of the response matrix technique for the optimal development of the aquifer of Viannos in the prefecture of Heraklion in Crete, International Conference on Protection and Restoration of the Environment XII,  Skiathos, 2014.

C.58. Theodossiou, N., Karakatsanis, D., Kougias, I., and Katsifarakis, L., Optimizing a typical water resources allocation problem using the Harmony Search Algorithm, International Conference on Protection and Restoration of the Environment XII,  Skiathos, 2014.

C.59. Dota, A., and Theodossiou, N., Estimation of green and blue water footprint. Application in the agricultural sector of Karditsa’s Prefecture, International Conference on Protection and Restoration of the Environment XII,  Skiathos, 2014.

C.60. Psarra, M., Sotiriadou, St., and Theodossiou, N., Simulation and operation of a geothermal groundwater aquifer, International Conference on Protection and Restoration of the Environment XII,  Skiathos, 2014.

C.61. Theodossiou, N., Fotopoulou, E., and Xefteris, A., The effect of hydrogeological parameters estimation uncertainty, in the delineation of well-head protection areas, International Conference on Protection and Restoration of the Environment XII,  Skiathos, 2014.

C.62. Tzamos, E., Tziritis, E., Vogiatzis, P., Matzari, C., Filippidis, A., Fytianos, K. and Theodosiou, N., Suitability of potable groundwater reserves of Thermi Municipality (Macedonia, Northern Greece) and definition of main hydrogeochemical signatures, International Conference on Protection and Restoration of the Environment XII,  Skiathos, 2014.

C.63. Katsifarakis, K.L., M. Vafeiadis, N. Theodossiou, Sustainable drainage and urban landscape upgrading using rain gardens. Site selection in Thessaloniki, Greece, IRLA2014 ‐ The Effects of Irrigation and Drainage on Rural and Urban Landscapes, 26‐28, Patra, Greece, 2014

C.64. Triantafyllou, V. and N. Theodossiou, Rainfall Forecasting Model using Artificial Neural Networks, 5th International Conference on Environmental Management, Planning and Economics (CEMEPE), 2015.

C.65. Kralli, V., Theodossiou, N., Th. Karambas, Combined use of simulation and optimization models for the optimal design of harbor breakwaters: Application at the port of Thessaloniki, 8th International Conference on Construction in the 21st Century (CITC-8), “Changing the Field: Recent Developments for the Future of Engineering and Construction”, Thessaloniki, Greece, 2015

C.66. Theodossiou, N., Kougias, I., and D. Karakatsanis, Optimal construction design using the Harmony Search Algorithm as an optimization tool, 8th International Conference on Construction in the 21st Century (CITC-8), “Changing the Field: Recent Developments for the Future of Engineering and Construction”, Thessaloniki, Greece, 2015.  

C.67. Dota, A and N. Theodossiou, Estimation of water footprint’s dimensions in the agricultural sector. Application in the R.U. of Karditsa, 9th national conference of the society of Agricultural Engineers of Greece, 2015.

C.68. Theodossiou, N and E. Fotopoulou, Application of novel optimization techniques in water resources management, AECEF 2015, 8^th Symposium, FEUP, pp. 35-42, Porto, Portugal, 2015.

C.69. Ντότα, Α. και Ν, Θεοδοσίου, Εκτίμηση του υδατικού αποτυπώματος των κτηνοτροφικών δραστηριοτήτων στην Π.Ε. Κατδίτσας, Κοινό συνέδριο: 13^ο Ε.Υ.Ε – 9^ο ΕΕΔΥΠ – 1^ο ΕΥΣ, Αθήνα 2015.

C.70. Παντελή, Ν.Μ., Θεοδοσίου, Ν., και Β. Τριανταφύλλου Ανάλυση και αξιολόγηση μετρήσεων στάθμης υπόγειου υδροφορέα Μουδανιών Χαλκιδικής, Κοινό συνέδριο: 13^ο Ε.Υ.Ε – 9^ο ΕΕΔΥΠ – 1^ο ΕΥΣ, Αθήνα 2015.

C.71. Σεβαστάς, Στ., Σιάρκος, Η,.Θεοδοσίου, Ν. και Ι. Υφαντής, Εφαρμογή γεωγραφικών συστημάτων πληροφοριών για τη συγκριτική αξιολόγηση μεθόδων οριοθέτησης ζωνών προστασίας υδρογεωτρήσεων, Κοινό συνέδριο: 13^ο Ε.Υ.Ε – 9^ο ΕΕΔΥΠ – 1^ο ΕΥΣ, Αθήνα 2015.

C.72. Theodossiou, N., D. Karakatsanis, and E. Fotopoulou, Introducing novel optimization techniques in irrigation pipe network applications, 2nd EWaS International Conference, 1- 4 June, 2016 – Chania, Crete, Greece, 2016.

C.73. Antoniou, M, N. Theodossiou and D. Karakatsanis, Groundwater management optimization with combined use of Harmony Search Algorithm and modular finite-difference flow model ModFlow, International Conference on Protection and Restoration of the Environment XIII, Mykonos, 2016.

C.74. Dota, A, N. Theodossiou and V. Dotas, Water resources use behind livestock and animal production with the water footprint approach, International Conference on Protection and Restoration of the Environment XIII, Mykonos, 2016.

C.75. Kourliti, E., Z. Mallios and N. Theodossiou, QGIS plugin development for automating a pressures-impacts analysis method, in the context of the European Water Framework Directive 2000/60, International Conference on Protection and Restoration of the Environment XIII, Mykonos, 2016.

C.76. Katsifarakis, K., Theodossiou, N., Artificial aquifer recharge by means of wells-Mitigation of water losses towards surface drainage system, 6th Environmental Conference of Macedonia, 2017.

C.77. Sevastas, S., Siarkos, I., Theodossiou, N. Ifadis, I., Kaffas, K., Comparing hydrological models built upon open access and/or measured data in a GIS environment, Sixth International Conference on Environmental Management, Engineering, Planning and Economics (CEMEPE 2017) & SECOTOX Conference, ISBN: 978-618-5271-15-2, 377-386, 2017.

C.78. Sigourou, S., Theodossiou, N., Rainwater and leachate management at sanitary landfills. The case of the residue sanitary landfill of Alexandroupolis, Sixth International Conference on Environmental Management, Engineering, Planning and Economics (CEMEPE 2017) & SECOTOX Conference, ISBN: 978-618-5271-15-2, 457-465, 2017.

C.79. Kougias, I., Patsialis, Th. Kazakis, N., Droege, P., Szabo, S., Theodossiou, N., Scaling up the stagnant small-scale hydropower capacities in EU, Sixth International Conference on Environmental Management, Engineering, Planning and Economics (CEMEPE 2017) & SECOTOX Conference, ISBN: 978-618-5271-15-2, 706-729, 2017.

C.80. Kougias, I., Szabo, S., Nikitas, A., Theodossiou, N., Modelling the transition to sustainable energy using harmony search: A water-energy nexus case in Greek islands, 10th World Congress on Water Resources and Environment “Panta Rhei”, Athens, 2017.

C.81. Theodossiou, N., Karakatsanis, D., Fotopoulou, E., The augmented Reality Sandbox as a tool for the education of hydrology to Civil Engineering students, IV International Conference on Civil Engineering Education, EUCEET 2018, J. Turmo, & J.A. Lozano (Eds), Barcelona, 2018.