Feasibility studies are required in the pre-production stages to justify the continued investment of money. Usually a scoping study is followed by one or more prefeasibility studies which reflect the increasing level of technical and economic knowledge gained at the various earlier stages.

Water is among the most essential resources that sustain Earth’s ecosystems, but these systems are currently under threat due to land use and climate change. Assessing the impact of this global change on water security and ecosystem’s functions is not only the key concern of the United Nation’s Sustainable Development Goals, playing a key role in sustainable development of society, but also the most important research focus in “Future Earth” and Earth critical zone research.

This is one of a Series of Volumes on Oceanography. It is designed so that it can be read on its own, like any other textbook, or studied as part of S330 Oceanography, a third level course for Open University students. The science of oceanography as a whole is multidisciplinary. However, different aspects fall naturally within the scope of one or other of the major ‘traditional1 disciplines.