FAQ

The Compendium’s indicators have a scientific basis and are subjected to a review process before they are published on the website. Users may consult the technical explanation (at the bottom of each indicator page) and follow the links to references, in order to determine how that particular indicator was created. For a large number of indicators, reliability is indicated according to a reliability code (A to F):

• A. Integral observation.
• B. Estimation based on a large number of very accurate measurements, with full or nearly full representativeness of the data.
• C. Estimation based on a large number of accurate measurements; representativeness is largely guaranteed.
• D. Estimation based on a number of measurements, expert judgements, and a number of relevant facts or published expert sources.
• E. Estimation based on a few measurements, expert judgement, relevant facts or extrapolation of other measurements.
• F. Estimation based on expert judgement, assumptions or extrapolation of foreign data.
   

The objective is to map the current situation for all the main issues around nature, spatial planning and the environment, and how these have developed. The precondition for doing this is correct measurement data. When choosing the indicators, the Compendium’s editorial team uses the following guidelines:

• The Compendium contains facts and figures that contribute to the quality of political and governmental considerations in the fields of the environment, nature and spatial planning, and it is primarily intended for making strategic policy decisions and science.
• Data presented in the Compendium must be representative of the main processes or policies on nature, the environment and spatial planning in the Netherlands, and they need to be expressive.
• These data mainly concern national figures, but may also be presented on a smaller or larger scale. Many policy fields need spatial differentiation, which is in line with 1) the scale on which the issue has manifested itself (global, European, national, and where necessary also regional), and 2) the sphere of influence of the competent authorities (EU, national government, provinces and municipalities).
• Data must originate from research that is repeated on a regular basis. Ad-hoc indicators are only presented if the current situation calls for their inclusion, or if the particular subject fills a certain gap. This concerns data that provide a picture of the current situation and the trend that has led to that situation. Where possible, the current situation and the trend are compared with policy targets and/or target values.
• The Compendium does not contain policy assessing indicators that are based only on models and assumptions about the influence of government policy on the sectors involved. The indicator information does not contain policy suggestions, but merely determines whether policy targets have been achieved, and provides explanations for the situation and/or trend.
   

There are two situations that may lead to an indicator becoming ‘dormant’. The first would be that of an indicator becoming less relevant. An example of such a case is when a particular policy is no longer in effect. The second situation would be a lack of data. In order to keep indicators up to date, data must be gathered from measurement networks, surveys or research.
Sometimes the information is no longer collected because it has become less relevant or due to a lack of funding. The Compendium will keep those indicators in its archives, but with the message that a current version is no longer available.

The objective of the Environmental Data Compendium is making scientifically founded facts and figures available, in order to support social discussion and choices in the fields of nature, spatial planning and the environment.

The Compendium presents the current quality of the environment, nature and spatial planning in the Netherlands, coupled to related government policies. Subjects vary from waste issues to climate change and from accessibility to biodiversity.
Information is mostly presented on a national scale, and in some instances, when relevant to decision-making processes, also on subnational or supranational scales.

The Environmental Data Compendium is jointly owned and managed by PBL Netherlands Environmental Assessment Agency, Statistics Netherlands (CBS), National Institute for Public Health and the Environment (RIVM) and Wageningen University and Research Centre (Wageningen UR). Three editorial teams (on nature, spatial planning and the environment), together with a large number of experts both from within and outside these institutes, ensure the information on the web pages is kept up to date. The editorial teams are supported by a project team and a steering committee, the latter of which is made up of management representatives of the four institutes.

The Compendium does not contain any policy assessments or outlook studies. These can be found in other media, such as PBL's Assessment of the Human Environment. Where relevant, the indicator pages provide information to such studies, at the bottom of the web page.