Focus on LIDAR method
One of the existing techniques to acquire topography datas on large scale peat sites is the method LIDAR (Light Detection And Ranging). From the interpretation of an airborne scanner campaign, LIDAR produces a digital terrain model (ground relief) and a digital surface model (surface relief, including for example the woody cover, buildings, etc. ). The extensive use of these data, using appropriate software, allows also to determines microtopography, including small inconspicuous channels on the ground, to model the areas that will be impacted, etc.
Surface topography can map the relief of the peat complex and study the surface water flow. It can accurately visualize the location of drains, old meanders or operating pits. These data contribute to a better understanding of the hydrological behavior of each site and causes of dysfunction.
The precise knowledge of the background and malfunction' causes of each bog is required to rehabilitate more efficiently and sustainably as possible. In karst context particularly, the analysis of the hydrological functioning of the bog and its watershed is sometimes essential. It is necessary to choose the appropriate intervention with the better ratio cost / effectiveness over the long term.
In this program, several steps must be conducted prior to the implementation of all functional rehabilitation:
- Acquisition and analysis of the general and timely data on topography;
- Piezometric and sometimes geochemical analysis of the groundwater tables;
- Analysis of interactions with the rivers;
- Ecological studies: habitats and species of community interest present.
All these studies are not systematized but will be adapted to the characteristics of each site, to operations to be conduct and to the possible regulatory procedures.
These preliminary studies will allow the definition of some bog restoration plans including :
- the definition of the objectives;
- the definition of the actions to be implemented;
- the definition of the specifications of the work and their chronology.
In accordance with French regulations, work in natural environments may require approvals from the authorities. These procedures are defined according to the object or extent of the operation, the presence of protection areas or legal status of the owner.
In the context of coherent management in the medium and long term of the project peatlands, management plans will be realized or updated for sites having the vocation : regional natural reserves and sites managed by CEN Franche-Comté.
Management plans identify issues of conservation and management objectives specific to the relevant bogs. They lead to the implementation of appropriates actions. These management plans will include:
- diagnosis: geology, soils, hydrology, uses, fauna, flora, vegetation, etc. ;
- the definition of conservation objectives in the mid and long term;
- defining operations arising from the objectives, planned over 5 or 10 years (time allowing for realistic planning and sufficiently regular evaluation).