Landfills and erosion
During rain events, raindrops have an impact on the soil as they detach soil particles from the ground, resulting in their suspension and subsequent transportation by surface water runoff. When there are no barriers that can act against this phenomenon, erosion can lead to large amounts of sediment leaving the site with the runoff water. This can result in the weathering of the surficial soil layer and in the case of old landfills, this can cause waste exposure. This waste can then end up in the environment, if transported by wind or water. Furthermore, rain will directly contact the waste, possibly contaminating the runoff water. To avoid these exposure pathways created by erosion, it is important to assess the erosion risks at your landfill site and to provide some barriers (e.g. vegetation, capping) if necessary.
This is also a very important aspect to take into account during a landfill mining or rehabilitation project. It is expected that existing barriers to erosion will be removed during the works on site (e.g. vegetation, capping). Therefore, it is recommended to implement erosion and sediment control (ESC) measures. For this, the Soil Risk Assessment (SRA) tool can be used in order to assess the efficiency of ESC measures and to determine areas with a high risk for erosion. The tool is based on the Universal Soil Loss Equation (USLE) and the Revised Universal Soil Loss Equation (RUSLE). More information on the tool can be found in the SRA handbook.
Regional tools
Flanders
In Flanders, a specific website is available on data for the subsurface in Flanders (Databank Ondergrond Vlaanderen). There, a specific tool is included, namely the Bodemverkenner. Within this geo-tool, data is available on erosion susceptibility and erosion control plans.
Wallonia
For Wallonia, the Walloon GIS geoportal WalOnMap includes a thematic map on the risk of diffuse water erosion, based on the Universal Soil Loss Equation (USLE). Additionally, maps on diffuse and concentrated runoff are available.
Germany
For Germany, information on erosion is available on the German Geoportal in which different thematic maps and data sources are included. In case of erosion, there are different maps available, with information on the risk of erosion from water and potential erosion hazard of arable soils due to wind or due to water.
United Kingdom
In the United Kingdom, with its long and extensive shorelines, coastal erosion and land instability are important risks for the region and the landfills that are closely located to the coasts. These risks can result in the recession of coastal lands. The environment Agency made some maps available on coastal erosion and on the shoreline management plans that are in place. They can be found on the website of the Environment Agency.