Towards standardised evaluative measurement of nature impacts: two spatial planning case studies for major Dutch lakes.

In the assessment of complex spatial planning projects, ecological and socio-economic impacts are fundamental to the evaluation. The measurements of the ecological impacts of spatial plans have to be integrated in a standardised way. In the present paper, two Dutch case studies are analysed and the standardised Threat-weighted Ecological Quality Area (T-EQA) measurement is applied. This measurement is developed to evaluate projects with terrestrial impacts, but has not yet been applied in water evaluations. The paper shows how the use of a common measurement tool incorporates both ecological quality and ecological threat in the criteria of the EU Water Framework Directive (WFD) and Nature 2000.