Services and Analysis

SISKA instruments underground cavities with various sensors to monitor physical and chemical parameters (flow rates, electrical conductivity, temperature, radon, CO2, methane, noise, etc.). SISKA offers its services for setting up hydrogeological surveys and monitoring groundwater quality. Wireless data transmission means that the measurements can be consulted in real time and alarm systems set up in the event of flooding or excessively high gas concentrations.

As part of impact studies, SISKA monitors reconnaissance drilling and accompanies geophysical investigations.

SISKA also specialises in monitoring and interpreting hydrogeological data from exploratory boreholes. It can also support geophysical investigations.

SISKA specialises in surveying and drawing up geological maps and topographical plans of underground sites (mines, quarries, caves, etc.). Using cutting-edge technology, the SISKA measures and maps underground cavities with a degree of precision adapted to each need (from quick sketches to detailed plans).

The application of new technologies to cavity topography (LiDAR, photogrammetry) involves the development of mapping, data management and archiving techniques. SISKA is focused on maintaining existing data while developing new acquisition and visualisation methods.

Mapping and inventory of karstic areas

The "Karst" map is produced based on an inventory of knowledge (geology, hydrology, vegetation) that makes it possible to identify regions prone to karstification that therefore require appropriate management. These data serve as a basis for applying the EPIK method for the protection of groundwater.

Inventory of sinkholes and lapiaz integrates local knowledge (speleologists, forest rangers, ....) and geographical analysis, combining soil mapping, detailed stratigraphy and geological structures. This data is used to identify areas of geological interest with a view to protecting them.

Analysis of collapses and recommendations

The presence of underground voids is often problematic, for example when building a wind turbine, a tunnel or a house. Exploration of a karstic network and its topographical survey are used to locate the presence of a cavity close to infrastructure. Detecting unknown cavities at depths greater than 15 or 20 metres is often difficult. However, in collaboration with various partners, SISKA is using and developing various geophysical methods to locate cavities from the surface. Our experience enables us to provide practical recommendations for managing these cases.

SISKA is a pioneer in applying 3D technologies to modelling underground objects (geology, mines, caves, underground structures) and groundwater.

In karstic regions, the flow of springs and rivers is controlled by the hydrogeological functioning of the underground karst. A 3D analysis of the subterranean layers enables us to assess flow rates and the basins that feed the springs. This knowledge is essential for assessing the risk of flooding during exceptional rainfall events, and the risk of drought.

SISKA offers digital solutions for simulate the behaviour of groundwater These results are important for the construction of underground structures. They also provide important insights for surface water and natural hazard management and impact studies, for example the determination of residual flowsTo do these simulations, SISKA uses a number of software programmes such as SWMM5 or RS Minerve.

SISKA maintains a field inventory of polluted cavities and dolines and adds them to the register of polluted sites. Some of these cavities have been known for a long time, but precise information is often lacking (volume of waste, access, type of waste).

A investigation report is drawn up for each region concerned, including a description of the site, a map of the cavity, photographs, the volume and type of waste and a remediation budget.

In coordination with the authorities (Communes, cantons, Confederation, army), the sites are remediated using specialised equipment and, with the support of civil servants, the waste is sorted and taken to reprocessing centres. Once the remediation is complete, a report is submitted to the authorities.

SISKA offers a service for identifying bones found in karstic environments.

Link to Archaeozoology competence

SISKA supports and carries out hydrogeological tracing tests by injecting a non-toxic, generally colouring substance into the environment (loss, sinkhole, cave, etc.). Field fluorometers, automatic samplers and fluorosensors are used to identify the sources connected to the injection point(s), and to characterise the link (speed, restitution rate, etc.). SISKA's fluorescence analysis laboratory can quantify tracer concentrations of less than µg/l.