|Sourcebook of Alternative Technologies for Freshwater Augmentation in Small Island Developing States (UNEP-IETC, 1998, 230 p.)|
|Part A - Introduction|
The first step in the use of this Source Book is to determine the type of island on which it is desired to implement a water resources development project. This helps to determine the choice of technologies applicable to that particular island(s) type(s). A discussion of the parameters that are used in this book to classify small island types is included in Section 5, Methodology, below.
Plate 1. Very small 'low' islands or coral atolls with non-existent surface freshwater.
Small islands can differ considerably and, for the purpose of this study, a distinction has been made between (i) very small, "low" islands (see Plate 1), and (ii) small, "high" islands (see Plate 2). Very small, low islands are generally characterised as coral atolls and sand islands with no surface freshwater resources, whilst small, high islands are characterised as volcanic and bedrock islands, or raised limestone and porous volcanic islands, where surface waters may exist. Technologies which are applicable to both types of small islands, which may be and often are applied in conjunction with more specific technologies, are found in Part B, Section 1, while technologies applicable to each particular island group are found in Part B, Sections 2 and 3, respectively. In addition, there may be islands where none of the technologies listed in Sections 2 and 3 are applicable, due to limiting factors such as little or no available freshwater, high population densities, etc., and on which it may be necessary to introduce more specialised, and, in many cases, more expensive, technologies for the augmentation of freshwater resources. These highly-specialised technologies are found in Part B, Section 4, and include desalination, importation and dual water systems.
Plate 2. Small 'high' islands where surface freshwater may exist.