Post-mining deformations in the area affected by the former "Siersza" Hard Coal Mine in Trzebinia (southern Poland)

Over the re cent years, post-min ing ter rain de for ma tions has been in creas ingly fre quent around Trzebinia. Sink holes ap pear ing in creas ingly close to build ings have be come a sig nif i cant geohazard. We show that post-min ing de for ma tions in the area is much more extensive than previously estimated. Identification of the deformations involved analysis of historical aerial pho to graphs, air borne la ser scan ning data, orthophotomaps and sat el lite ra dar data. More over, la ser scan ning of se lected ar eas us ing an un manned ae rial ve hi cle and a ter res trial la ser scan ner was car ried out to gether with field map ping. In the study area, 527 sink holes and 254 lin ear-type de for ma tion struc tures were iden ti fied. Com pre hen sive map ping of sink holes - in clud ing those pre vi ously un known, lo cated out side built-up ar eas - showed that ar eas where sink holes had been remediated in the past were also at sig nif i cant risk. A num ber of sink holes are also lo cated out side ar eas of shal low (up to 100 m be low ground level) min ing. The use of sat el lite ra dar in ter fer om e try showed that con tin u ous de for ma tions also oc curs in the area of in flu ence of the for mer "Siersza" Hard Coal Mine. In the past, sub si dence of this ter rain took place, while currently up lift is tak ing place in this area which lo cally reaches up to 20 mm per year.