The amount of Earth observation data is getting larger day by day. This rapid evolution of the field and the exponential growth of data generation mediums urges the need for modern ways of fast analysis and processing of satellite images. Earth Observation Data Cubes enhance the way Earth data are distributed, handled, stored, and analyzed by providers and users. In this study the development of the National Earth Observation Data Cube of Cyprus is described and the importance of such software-based infrastructure is demonstrated through a water resource monitoring use case in the context of climate crisis in the Mediterranean region. Moreover, this study exhibits the capabilities of semantic classification in Earth observation, introducing a spatially generalized approach for easier environmental monitoring. Such developments can enhance the preservation of the environment and its protection from future natural and human disasters.