Evaluation de la multifonctionnalité des aménagements de lutte contre le ruissellement et l'érosion des sols sur la ceinture loessique belge

Abstract

The Belgian loess belt and its watersheds are particularly affected by runoff and erosion [Bielders et al., 2003], causing significant damages [Dogot et al., 2019]. Specialists are reflecting on watershed management which, in addition to combating these disturbing phenomena, promotes a wealth of ecosystem services (ES). The objective of this work is to evaluate the ecosystem services of different existing developments in the fight against runoff and soil erosion in an agricultural catchment in the Belgian Loessic belt. Based on the work of [Cantreul, 2020], nine management scenarios of the experimental watershed of Chastre, in addition to the initial scenario, are used to evaluate the services of pollination, carbon storage, agricultural production, landscape attractiveness and erosion prevention. These scenarios are established by specialists on the basis of grassed strips and channels, wooded strips, hedges, fascines and changes in the direction and intensity of tillage. The ES of pollination, carbon storage and erosion prevention are assessed using InVEST models. A methodology based on the loss of utilised agricultural area (SAU) is developed for the agricultural production service and a survey-based methodology is used for landscape attractiveness. The results obtained are rich and varied. The scenarios with the best results for pollination, carbon storage, landscape attractiveness and erosion prevention are also the most expensive to implement and they have the greatest impacts on SAU. The choice of an ideal management scenario must take into account the trade-offs between ES and the synergies between them.