In accordance with the objectives outlined by the LIFE RIBERIME Project and following the guidelines of the “Lousal Restoration Plan”, a document jointly produced by the partners, the Lousal Pilot Project (PPLousal), whose practical works are coordinated by the Centro Ciência Viva do Lousal, in close collaboration with the Complutense University of Madrid, is in full development and close to completion.
The practical implementation of PPLousal in the field began on September 20th, and its completion is scheduled for the first week of November 2021. As a result of a multidisciplinary intervention, with an experimental and demonstrative nature, the PPLousal focuses on the ecological restoration of an area of approximately 1.6 ha, in the former Lousal Mine, where pyrites were unloaded for transport by train, to their destinations for processing and transformation, at the facilities of SAPEC in Setúbal. The PPLousal aims to contribute to mitigate the environmental and landscape impacts caused by metallic mining (DAM – Acid Mining Drainage) on the soils and waters of the region, seeking solutions to improve their quality, and to safeguard the natural habitats and regional biodiversity.
Preparatory works, prior to intervention (removal of the existing vegetation). Photo: @BrunoGonçalves
Placement of stakes, for topographic survey and terrain marking. Photo: @BrunoGonçalves
Using the Best Available Techniques (BAT) for mining restoration, in Europe and worldwide, PPLousal is based on the creation of a small hydrographic basin, where the land is remodeled and reconfigured according to innovative geomorphological methods (GeoFluvTM) that intend to recreate a relief close to natural in order to reduce erosion. It is also the first European Project, where these methods are combined with the chemical correction and stabilization of soil and water affected by DAM, through chemical processes.
Start of the land mobilization works. Photo: @BrunoGonçalves
Land reconfiguration using bulldozer. Photo: @BrunoGonçalves
The works consisted, in a first phase, in the topographical remodeling and reconfiguration of the land, in soft reliefs, which “mimicking” the undulations of the relief, characteristic of the cork oak and holm oak forests (“montado”) surrounding Lousal Lousal. They were followed by the application of layers of limestone materials, mixed with clay, in order to promote chemical reactions with rainwater, toraise the pH, currently very acidic, to values closer to neutrality, thus correcting the acidity of water and soil.
Terrain observation, for technical specifications to the maneuvering machinist
Terrain appearance during the geomorphological modeling. Photo: @BrunoGonçalves
Then, the land was covered with another layer of organic matter, consisting of natural fertilizer of animal origin (poultry and horse manure) mixed with a compost based on plant soil, which aims to recreate the surface layer of the soil, that will serve also as a substrate for a vegetation cover.
Discharge of the organic compost.
The mobilizing of land and materials was carried out using a bulldozer and D6.
For revegetation, a few dozen herbaceous and shrub species native to the region, were selected, whose seeds were collected and stored in order to be able to colonize this area. Sowing is soon, waiting for the start of the autumn rains, so that there is sufficient soil moisture to guarantee the viability of the seeds germination. With this phase of the intervention, it is expected to implement a vegetation cover with prime-colonial species, adapted to the conditions of the “soil” recently recreated, which will subsequently evolve and develop according to the typical natural successions of the regional vegetation.
Part of the field team (CCVLousal, UCM and contractors).
Some of PPLousal’s operational (contracted companies, UCM and CCVLousal).
Filling of pre-existing drainage ditches with limestone gravel. They were later covered with geotextile to prevent contamination with the mobilized lands.
Coverage of drainage ditches, filled with limestone, with geotextile.
Very close to completion, the works for the practical implementation of PPLousal have proved to be an interesting logistical and operational challenge. Despite the experimental and innovative nature of the techniques and methods used, step after step, the constraints have been overcome within the expected execution times, and their goals successfully completed!
Aerial photo of the intervention area, at the time of defining valley zones and main channels. Photo: @BrunoGonçalves
Completion of the geomorphological reconfiguration of the terrain. Members of the operational team (CCVLousal, UCM and company contracted for land mobilization).
Aerial photo of the intervention area, during the spreading of limestone and clay Photo: @BrunoGonçalves
Another angle of aerial photo of the intervention area, during the spreading of limestone and clay Photo: @BrunoGonçalves
Spreading of the topsoil (vegetable humus, bird and horse manure).
Appearance of the terrain, after partial spreading of the superficial layer, rich in organic matter.