Hydrogeological Characteristics of the Area of Intermittent Karst Lakes of Pivka

Abstract

Poseben hidrološki pojav zahodnega dela kraškega masiva Javornikov so presihajoča Pivška jezera. Za celotno območje je značilna tesna povezava podzemnih in površinskih voda. V kraškem vodonosniku se vode pretakajo večinoma podzemno, ob močnejših in dolgotrajnejših padavinah pa se nivo podzemne vode dvigne in voda se na številnih mestih preliva na površje. Tako postanejo aktivni občasni kraški izviri ob reki Pivki, z vodo pa se napolnijo tudi kraške depresije in nastane večje število presihajočih kraških jezer. Nekatera se pojavljajo dokaj pogosto in imajo vodo tudi do pol leta, večinoma pa so bolj redka ali so zalita samo izjemoma v času močnejših poplav. V članku so predstavljene hidrogeološke značilnosti območja, ki se odražajo v režimu pretakanja kraške vode in načinih njenega pojavljanja na površju.

A special hydrological feature of the western part of the Javorniki karst massif is the intermittent karst lakes of Pivka. For the whole area a close connection between underground and surface water is characteristic. In the karst aquifer water flows mostly underground, but after more intensive or long-lasting precipitation the water table rises and water emerges on the surface at different locations. Intermittent karst springs along the Pivka river are activated. Also karst depressions are filled with water and several intermittent karst lakes can be formed. Some of them appear very often and contain water for up to six months, but mostly they are very rare and filled up only exceptionally in the time of big floods. In the article the hydrogeological characteristics of the area are presented, which are reflected in the flow regime of karst water and in the forms of its appearance on the surface.