4. options for development of a EEA monitoring net
Section 2 has described the need for objective, reliable and comparable information on Europes water resources. Section 3 has illustrated that it is unlikely that the information supplied by Member States for compliance with EC directives and other International Agreements will be suitable or adequate to meet that need. There are, however, a number of additional options on how the network for obtaining the information required (by the EEA) can be developed. These include:
Use of current national classification schemes. A number of Member States that have their own general quality assessment schemes or classifications reflecting local national contamination levels/quality using national class limiting thresholds or rating values. These are often based on different indicator determinands, sampling frequencies, and reporting statistics. It is unlikely, therefore, that all national classes would be immediately transferable to a unified European classification scheme. However, the raw data used to derive the national classifications are likely to be more suitable for use in the EEA network if the data were able to be treated or aggregated in a consistent way. It should also be noted that the proposed EC Directive on the Ecological Quality of Water (now encompassed in the proposed Framework Directive on Water Resources) aims to introduce a common rating system across Europe so that different relative values of quality will be equivalent from one country to the next. In the case of river invertebrates national ratings may be able to be translated to a unified scale.
Sample and measure all water bodies in a consistent and comparable way which would clearly be very expensive to undertake and co-ordinate, and difficult to manage, interpret and report the resultant large quantity of information. It would probably also be unnecessary in terms of the additional information that would be obtained.
Sub-sample a representative portion of the total water resources. This would be aided by stratifying the total population (e.g. all rivers) into relativity homogenous sub-strata. In selecting the representative portion it would have to be ensured that a statistically biased sample was not being taken or else a true spatial and temporal comparison across Europe would not be possible. This would be more difficult to implement and would probably require a number of sequential phases. The first phase would be the initial selection of sampling sites and data requirements on all types of water body from a number of selected countries. Data from these would be obtained and statistically tested to modify the initial design so that optimum sampling density can be implemented. The revised monitoring protocol would then be progressively implemented in all EEA States.
Option 3 is considered to be the best option in terms of cost-effectiveness and feasibility. The following section outlines how this approach has been used in the design of the networks.
For references, please go to http://www.eea.europa.eu/publications/92-9167-024-3/page005.html or scan the QR code.
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