This research documents the successful application of a novel holistic approach to return land degraded over thousands of years of use to full ecological function. The surroundings of the Somolinos hamlet in Central Spain illustrate a millennial history of land transformation and degradation by agrarian and extractive activities exacerbated at the second half of the 20th century by mechanized mining. This land stewardship history was culminated by a recent intervention of geomorphic-based ecological restoration and its monitoring. Historic anthropogenic processes which triggered gully erosion were intense deforestation for agriculture and grazing, and construction materials quarrying. From 1963 to 2006 mechanized quarrying operated over ancient extractive landforms. In 2007, a conventional rehabilitation mitigated risks but failed at controlling erosion and promoting soil and vegetation reestablishment. A geomorphic-based ecological restoration was accomplished since 2011. The GeoFluv-Natural Regrade CAD software was used for geomorphic landform design, and construction was completed with a carbonatic colluvium topdressing supplemented with a manure-amended soil, that was seeded with grasses. The whole process was a truly complete application of ecological engineering. One of the main purposes of this research was to carefully scrutinize the completed project, to evaluate its effectiveness and, if any deficiencies were found, to analyze their causes, so that they could be avoided in the future. Therefore, the landscape evolution and erosional behaviour of the restored area has been monitored from 2011 to 2020 through a time-lapse sequence of several oblique aerial photos, and by comparing topographies through Digital Elevation Models (DEMs) of Difference (DoDs). Those topographies were surveyed with differential GPS (DGPS) and with Structure from Motion (SfM) combined with Unmanned Aerial Vehicles (UAVs). This monitoring revealed: (a) landscape healing and diversification of the vegetation community composition and structure, as a result of the environmental heterogeneity of the geomorphic design; and (b) absence of hillslope and channel erosion for 99.8% of the area with limited surface erosion zones in 0.2% of the restored area. Our analysis attributed those limited erosion zones to a combination of: (a) minor design oversights; (b) slight construction deviation from the design grade; and (c) excessive runoff entering the repaired area that exceeded the design discharge. These erosion zones started to stabilize five years after initial restoration and achieved steady-state stability at nine years. The main lesson learnt from these minor deficiencies is that such erosion zones can be avoided at the design phase within GeoFluv-Natural Regrade by checking proper convex-concave slopes and concave channel profiles and by carefully considering any adjacent runoff entering the designed areas, which influence the channel's tractive forces. The use of Landscape Evolution Models, such as SIBERIA, can also identify design anomalies subject to erosion. Then, after rigorously inspecting the design, it is imperative that the construction is completed true to the design by defining and following construction tolerances.

Fluvial geomorphic approaches for reclamation landform design have been applied since 2000, mostly in mined lands, as an alternative to conventional landform design methods. Those approaches aim to reconstruct mature landforms and drainage networks that would develop within a natural catchment, after thousands of years of work performed by geomorphic processes. Some fluvial geomorphic design methods take specific measurements from natural and stable reference areas for initial input values for reclamation design. Valid reference areas can be difficult to find, can be in highly anthropized environments, or may be difficult to access. This paper evaluates the use of remote sensing tools to measure morphometric parameters in upper sections of agricultural land catchments considered for use as reference areas. The ridge to head of channel distance (Xrh) was the parameter of interest. We used land surface profiles developed from LiDAR (Laser Imaging Detection and Ranging) data and planimetric measurements from orthoimages to estimate Xrh. The results obtained by the two methods were encouraging but showed a significant difference. Ground truthing showed that ploughing obliterated between 19.5 and 22.4 m (on average) of the headwater section of first-order channels, reducing the channel length by 15.1 to 32.4%. Using a greater Xrh value than appropriate for near steady-state conditions as a design input for a geomorphic reclamation project would be expected to result in active erosion processes in the constructed reclamation to regain their missing channel length. We recognize the advantages and limitations of remote sensing methods for measuring the morphometric parameters of the landform relief design inputs. We show how these tools may be used to help select and prioritize reference areas, and warn about the use of disturbed landscapes as reference areas to assure the geomorphic stability of the constructed reclamation designs.

San Juan Coal Company reclaimed 743 ha at its La Plata Mine using the GeoFluv (TM) fluvial geomorphic reclamation design method from 1999 through 2008 to achieve long-term stability against erosion (no major slope blowouts and rill and gully formation), reduced maintenance, and increased biodiversity as compared to traditional reclamation methods (e.g. terrace, berm, and downdrain designs). Qualitative inspections of the completed reclamation confirmed the fluvial geomorphic reclamation method benefits. In the fall of 2011, the company began implementing a research study to quantify the sediment production rate from these geomorphic landforms and surrounding undisturbed native lands. Data were acquired from subwatersheds differentiated as native (undisturbed by mining), fluvial geomorphic design with topdressing and poorly established vegetation, and fluvial geomorphic design with topdressing and significant vegetation establishment. The three subwatersheds were selected to ensure similar size, aspect, and slope and were located close together to minimize storm variation effects. Temporary check-dam-type sediment control structures designed to impound runoff from a 2-yr, 1-h storm were installed at each subwatershed outlet. Erosion pins in the impounded area facilitated sediment deposition measurement. Precipitation was recorded by the La Plata Mine Meteorological Station and supplemental site-specific precipitation gauges. Precipitation sufficient to cause sediment transport provided data for the end of the 2012, all of the 2013, and the beginning of the 2014 water years. The site data provided direct relationships between sediment production and precipitation. The sediment yield from the undisturbed native site was 9.53 t ha(-1) yr(-1), while the fluvial geomorphic design with topdressing and poorly established vegetation site averaged 13% lower than the native site, and the fluvial geomorphic design with topdressing and significant vegetation establishment averaging 41% lower sediment yield than the native site. Land-disturbing activities that can accelerate erosion and sediment yield will accompany global population growth. The results of this study indicate that use of this land reclamation method can mitigate erosion and sediment yield increases associated with that growth.

This research describes a geomorphic-based process of mining reclamation carried out at the El Machorro mine (at the edge of the Alto Tajo Natural Park, East Central Spain) and its monitoring for five years (2012-2017). The GeoFluv T method implemented by the Natural Regrade software has been used to design small watersheds as a mining reclamation topographical solution. The procedure included: (i) finding a suitable reference area with stable landforms and acquiring inputs from them; (ii) designing two first-order stream watersheds; (iii) building the planned landscape; and (iv) monitoring the hydrological and erosive -sedimentary response of the reclaimed watersheds. This process is in itself a contribution to global advancement of reclamation best practices, because there are very few geomorphic-based mining reclamation examples, and even fewer that include their multiannual monitoring. Sediment yields were obtained comparing Digital Elevation Models (DEM) acquired by Total Station (TS), Terrestrial Laser Scanning (TLS), differential Global Positioning System (GPS) and topographic reconstructions (interpretations). An H-flume with turbidity and water pressure sensors allowed quantifying runoff and suspended sediment. Sediment yield progressively decreased with time attaining a current low value (4.02 Mg ha(-1) yr(-1)). Water discharge and suspended sediment concentration have also decreased with time. Initially, high sediment yield values were obtained. They are interpreted as being triggered by grading errors that deviated from the design, so that runoff adjusted construction irregularities during that period by erosion and sedimentation. After those adjustments, the reclamation surface became more reflective of the design and the resulting surface remained very 'stable'. The deduction is that the geomorphic-based reclamation has re-established an approximate steady-state or dynamic equilibrium, where hydrological and erosive -sedimentary functionality operate now at rates comparable to the surrounding natural land. Although further research is required to confirm long-term stability, geomorphic reclamation appears as an efficient mining reclamation alternative solution to the traditional approach of gradient terraces and downdrains, which require frequent and costly maintenance, in the highly erodible setting of the Alto Tajo Natural Park surroundings, as well as in most open pit mines.

Comunicacion presentada en: VI Congreso Nacional de Evaluacion de Impacto Ambiental: Responsabilidad, Vigilancia, Eficacia (VI CONEIA), Albacete, abril 2011.

En este articulo se describen los aspectos fundamentales de un Plan de Restauracion. Se explican las actuaciones realizadas en el caso concreto de la cantera los Quebraderos de la Serrana (Noez, Toledo). Primero se realiza una reconstruccion geomorfologica, para despues proponer un diseno de explotacion y restauracion que compatibiliza la obtencion de aglomerado asfaltico, con la conservacion del aguila imperial. Al final de este articulo se llega concluye que deberian realizarse este tipo de actuaciones frente a la mera correccion 32 del impacto visual.