Nitrate pollution risk assessment: from the model to the indicator

The diffuse nature of nitrate pollution makes it difficult to evaluate existing or planned measures to reduce it. Tools have therefore been developed to assess this pollution, ranging from simple indicators to complex models. The aim of this paper is to compare indicators and models by analysing results obtained from their individual application to the same area. The pros and cons of each approach are evaluated in terms of both the conditions of their implementation and the results obtained. This comparison helps to guide the choice of a methodology. Rules governing that choice are set in relation to the nature of the diagnosis to perform and the characteristics of the area under study.