Beekdalbufferzones en infiltratiegebieden als basis voor ecologisch functioneren en inrichting van beekdalsystemen

Hydrology is an important driver in the restoration of aquatic ecosystems, biodiversity and water quality. To restore ecologically robust watersheds after a period of intensive drainage a more regional and integral approach is necessary, encompassing measures at the drainage basin scale instead of local small-scale restoration measures.

Over the past years there have been many efforts to halt the deterioration of aquatic ecosystems and to initiate restoration. However, due to intensive drainage, the natural carrying capacity of regional water systems on sandy soils has been affected. Recent Dutch and European evaluations point at a limited effectivity of small-scale restoration efforts, and pledge for a more regional and integral approach which targets ecosystems on a landscape-scale. The current climate-, nitrogen- and biodiversity-related challenges demand a reconsideration of the countries spatial planning of rural areas. This provides opportunities for the coupling of aquatic, terrestrial and climate restoration and mitigation goals.

The fundamental scientific knowledge for a transition to a water-based spatial planning is available, but the translation to restoration practice needs a framework and practical quantified instruments. Therefore, a new fundament of knowledge for water-based spatial planning is developed. The knowledge consists of an ecological (functional) systems approach to aquatic ecosystems, which involves quantifying water and nutrient flows and related processes, selecting ecohydrological indicators, quantifying indicator response values for relevant environmental factors, and by scaling up these findings to formulate potential restoration measures. These components will be addressed using case-studies.

The theoretical most successful restoration measures on the Dutch sandy soils include the construction of buffer zones in lowland stream valleys and improving infiltration capacity in designated infiltration areas. In the practical implementation of these buffer- and infiltration zones, natural processes on a system scale are leading (building with nature).
In addition to biodiversity- and water quality goals, other ecosystem services benefit, such as precipitation storage in stream valleys, climate adaptation, human wellbeing / recreation, and drinking water supply. This systems approach offers insights to approach LNV-policy integrally and sustainably, where it is essential to combine biodiversity-, water quality-, food production- and climate goals in spatial planning.