To the Problem of the Assessment of Karst Economic Risk for Pipelines (by the Example of the Tatarstan Republic Southeast)

The territory of the Tatarstan Republic is located within the soluble Permian sequences (mainly limestone, dolomite and gypsum), which occur at a low depth under the surface (up to 200–300 m). About 96% of studied territory is karst hazardous. Oil and gas pipelines, as well as pipelines of different purpose (the total length over 55 thousand km) are maintained within the limits of the Tatarstan Republic territory. The paper is devoted to main approaches for karst economic risk assessment with reference to pipelines. The algorithms of the probabilistic-deterministic assessment of karst economic risk on regional and local levels by the example of karst terrain in the southeast of the Tatarstan Republic are the subject of our discussion. The assessment of karst economic risk of the losses is carried out on the basis of the analysis of geological structure of territory, hydrogeological and engineering-geological conditions of territory, identification and prediction of karst hazards in time and space, assessment of vulnerability of linear objects to karst hazards. The obtained values of economic risk are the basis for choosing alternative pipeline routes, for estimating service conditions and engineering protection measures.