Using geomorphology to design, build and assess a post-mining landscape: a case study of the Santa Engracia mine, Spain

Abstract

New computing and modelling technology allows the reconstruction of post-mining landforms using geomorphic design principles. It is important that such designs be evaluated and if needed, re-designed or reshaped so that soil loss is minimized and geomorphologically and therefore ecologically integrate with the surrounding landscape. One landscape assessment method is to use a computer based Landscape Evolution Models (LEMs). LEMs allow different designs to be input and will highlight where erosion will occur and type of erosion (i.e. sheetwash, rilling, gullying) as well as erosion rate. Here, landscape designs for the Santa Engracia mine in East-Central Spain were designed and constructed using geomorphic principles using the GeoFluv method and Natural Regrade software. These design landscapes were evaluated using the SIBERIA LEM. The results demonstrate that using suitable topsoil and if vegetation can be established the landscapes will have minimal sheet and gully erosion.  Erosion forecasts (5.3 - 15.2 t ha-1 yr-1) are significantly lower than the previous landscape (~350 t ha-1 yr-1) using conventional (terraced) reconstruction methods. The design and assessment methods described here provide procedure that can be used at other sites to highlight strengths and weakness of a landscape design process. The combination of geomorphic design and assessment using a landscape evolution at this project (LIFE RIBERMINE) presents a new standard for mine rehabilitation landform design in Europe.