Groundwater (GW) is one of the most valuable natural resources and for that reason, the GW protection and management is vital for human evolution, socio-economic development and ecological diversity. During the last decades, the continuously increasing need of water has led to a rapidly growing awareness in the field of GW management. At the same time over exploitation and pollution of water resources are threatening the ecosystems. The combination of these two problems which have acquired world-wide dimensions has forced many scientists working in relative fields to search new, multidisciplinary approaches to address them. Effective management and protection of groundwater resources require detail knowledge and quantitative/qualitative characterisation of aquifers. Thus, modelling and planning of the GW through the use of modern technologies and approaches have become of high priority towards this direction. This book provides leading-edge research on this field.