Spatial comparison analysis of farm patterns and water catchment areas

Abstract

The protection of drinking water catchment areas (CA) is a major sanitary and ecological issue for local authorities and other stakeholders in water management involved and impacted by the implementation of action programmes in their territories. Many regulatory procedures concerning water quality preservation begin with the definition of territorial boundries by means of hydrology. However, these boundaries intersect with those of agricultural plots. Understanding how these two overlap is of interest for water agencies and water distributors looking for solutions that take into account both, water quality and farmers' working constraints. The combined use of GIS layers for delimiting areas and agricultural national databases, such as the graphical parcel register (registre parcellaire graphiqe, RPG), makes it possible to incorporate these issues by analysing indicators such as the share of farmland of the catchment area cultivated by each farm (weight), or the share for each farm of its farmland included in the water catchment area (importance/concern).