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.