Retrospective approach to determining the genesis of sinkholes on the earth surface (by the example of Troitsk and Novomoskovsk districts, Moscow)

: The density and sizes of surface manifestations of karst, karst-suffusion and suffusion (not related to karst) processes are the necessary information for zoning territories according to hazard categories. For natural areas, that are little affected by human activities, the task is only to find depressions. In a territory, which is characterized by a rich history and lack of modern construction and agricultural activities, it is relevant to determine the origin of the detected drainless depressions, because people have greatly change the landscape over the centuries of their residence (not always peaceful). At the same time, determining the origin of a relief form on the basis of morphometric analysis is not always effective.