Natural Regrade Carlson with GeoFluv Method A new approach to the geomorphic reclamation of disturbed lands Transcript slide 1. Natural Regrade is a new geomorphic approach to the reclamation of disturbed lands by applying GeoFluvTM method through The Natural Regrade software (Carlson). The GeoFluvTM method was patented by Nicolas Bugosh and first implemented in La Plata Mine in 1999 in New Mexico. Along this lecture I would like to show you the advantages of using Natural Regrade against the traditional techniques Gradient Terraces in the mine’s reclamation. Transcript slide 2. Why do we need reclamation? Nowadays we cannot enjoy our comfortable life without mines. This sentences: “If It isn’t grown it has to be mined” perfectly defines the implications that this activity has in the currently society. Despite people dependency on mineral resources, mines affects all the environmental components (Zapico et al. 2011) so we also have to face the environmental problems derived from it. In the picture d) it is shown an example about the degree of degradation (soil acidification; bare soil; water erosion) that a nonreclaimed mine could reach even 100 year after closure. Transcript slide 3. By applying ecological restoration techniques we can avoid mine activities achieving such a degraded state. When we want to restore an ecosystem we should consider three main dimensions, the scientifictechnic, the sociological and the economical. Any restoration project could success without taking into account the needs of the society, the economic development of the region and the ecological sustainability of the disturbed land. Most of the reclamation techniques applied by private companies in mines fails in the ecological dimension since they are not recovering the ecological processes inside the quarry. In the reclamation of a mine there are three main actions that have to be accomplished: Geomorphic reclamation, promoting soil recovery and enhancing vegetation. Transcript slide 4. During this lecture I will be focus on the first one applying GeoFluv method which works copying the natural landform building with them an eco-hydrological reclamation final design. This method is based on fluvial geomorphic principles such as, drainage density network, channel’s geometry and topography of stable slopes. Let’s go on take a look at the picture below on the left side; here you can see the drainage density of a not reclaimed quarry. Considering this information the reclamation team managed to achieve the ecological processes recovery by creating watershed. Nevertheless is started as a first approach of the
integration of the fluvial geomorphic principles without considering the channel’s geometry so the long term sustainability is not ensured. GeoFluv method offers an more integrated approach. Transcript slide 5. What happened if we ignore the stability of the soil resources? If we try to remember how the landforms are in nature we realize that they are not following geometric patron. As you can see in the picture 1) the natural watershed shows a network of slopes with concave longitudinal profiles. On the next picture (2)) you can see a quarry reclamation, free of maintenance from 1995, that applied the ‘high wall–trench–concave slope’ method (Martin-Duque et al. 2010). Nevertheless this was an isolated example, usually the traditional reclamation techniques promotes just the opposite approach, instead of copy the natural landform they have been building stairs in nature… On picture 3) you can see how unsuccessful this reclamation resulted after 17 years. The ecosystem needs to achieve a stable state and to do that erosion processes will keep going until reach concaveconvex longitudinal profile. Transcript slide 6. What is new in Natural Regrade method? We have been talking about how Natural Regrade keep the hydrologic balance of the landform but there are other advantages of using this software that make it a better option against the old techniques. The project costs will be reduced because it works with in-side materials, save money on materials moving and offers self-maintenance. It will also promote plant and wildlife diversity by increasing the slope aspect diversity. GeoFluv approach had been awarded by the USA Government considering as National and Best of the Best reclamation award for 2004. On the picture 2) you can see the aspect of the Cottonwood after 10 years of implemented GeoFluv method. Transcript slide 7. When we want to start a design in Natural Regrade we need to know that it works on AutoCAD. A topographic map of the quarry and the surrounding is needed as well as other characteristic that are essential data for the software such as have local clime data, type and quantity of the waste material (inside material with which we will design the landforms) and the most important one The Natural Reference. Identifying the reference is probably one of the main steps; it will give us basic data that the program will use to build the channels inside the quarry. To select a proper reference are we have to focus on looking for are with the same waste material and with similar slope. Ones we found it we need to take measures of the channels and calculate the drainage density which can also be done using ortophotographies.
Transcript slide 8. Before start editing the channels we should take some time to look at the main points from where the water enters inside the reclamation area. This will provide some clues to start drawing the channels. The channels need to be validated by the program which tell us if they with be stable or not. At this step others options appears and we can take a look to the channels. We will notice that the channels are based on those classification proposed by Rosgen, 1994 according with there are only two type of them with a zig-zag morphology and meandering. If we hadn’t designed enough channels the target density will appear in red and that means that we have to increase the number of channels. Transcript slide 9. When the target density turn green we can go on run the software and we will obtained a 3D model. I would like to highlight that we can reconnect the mine with the drainage network outside the quarry or left it as a pond (figure c) of the slide 10). Once the final design had been accomplished a detailed report we will created with all the information of the channels and the areas of cut and fit that could be connected with the earth moving equipment. This will be very useful in terms of planning an effectiveness reclamation in an active mine (achieving the coordination between extractive activities and reclamation) and also in terms of saving cost because the planning on the material movement. Transcript slide 10. I will introduce two proposals of reclamation and two examples of truly geomorphic reclamation on in Spain. In this framework Spain can claim to have been pioneering in both the design and the construction of mining geomorphic reclamation in the mid-1990 (Martin-Duque & Bugosh 2014). From 2009 the work of the Restauracion Geomorologica group in Spain is mostly based on GeoFluv method. Here you have an example of Los Quebraderos de La Serrana which is a slate quarrying project located in a habitat classified as ‘important’ for the Iberian Imperial eagle. The regional environmental regulators didn’t authorize the previous version of the project, based on traditional mining reclamation approach. The GeoFluv method revealed that the geomorphic reclamation proposed make compatible the mine activity with the conservation of this bird of prey. Providing at the end of the reclamation process with high biological diversity and 5 different kinds of habitat were created, as you can see in the picture c). Transcript slide 11. The next example is my master thesis for the Ecosystem Restoration Master. I focus on offering alternatives to the traditional reclamation techniques in a clay mine. The area presented active process of erosion and a high level of sediment emissions that were affecting the river downstream. With The GeoFluv method I managed to present an alternative that better control the erosion and reduces the sediment emission as well as reconnecting the drainage network to improve the water quality
downstream the quarry. In the meantime the area can have higher biodiversity than with the traditional reclamation proposed since two new habitats were created.
Transcript slide 12. As follow you can see a truly geomorphic reclamation. Reclamation of Somolinos Quarry, Guadalajara Province, Spain. On the picture you can see the different between the area reclaimed by the traditional approach with severe erosion in platforms and slopes in comparison with the right side where GeoFluv method was applied and the erosion was controlled. The reclamation team was capable to prove it after extreme event in the zone. GeoFluv is one more time the best option to promote stability and enhanced biodiversity. Transcript slide 13. This last example seems to be the most challenging reclamation of all presented today since it is located in a Natural Park outstanding value. The mines were causing sediment contamination in a high value freshwater ecosystem. GeoFluv method provides the area not only with the advantage that we had been speaking about during this lecture but also it was goo option to reconcile the tourist development of the region with the mining activity.
Sara Pelaez Sanchez European Commission DG Joint Research Centre Environmental and Sustainability Institute Trainee at Water Resources Unit H01 IPR-46 01/107 Contact: +(39) 0332 789206 Via Enrico Fermi, 2749, 21027 Ispra Varese
[email protected] [email protected]
