RELATIVE IMPORTANCE OF BASEFLOW AND QUICKFLOW FROM HYDROGRAPHS OF KARST SPRING

Evaluation of recession hydrographs, from four karst springs in Europe , provides important information concerning the flow process operating in karst aquifer systems. Three analytic equations are used to evalua te the hydrographs: Mangin's equation, that assumes the recession is c omposed of both quickflow and baseflow; Coutagne's equation which cons iders the recession to be the response of a single reservoir; and a ne w function, H(t) (which is derived from Coutagne's equation), that ref ers to the whole recession curve. Using Mangin's equation it is appare nt that the saturated zone and thus baseflow exerts nearly complete co ntrol over the discharge of La Villa spring and is fairly important at Fuente Mayor and Baget springs, but is much less significant at Aliou spring. The saturated zone accounts for 100%, 90%, 91%, and 40% respe ctively for these springs. Using Coutagne's equation and H(t) it is co ncluded that for Aliou and Baget springs, water flows freely in the hi gh transmissive zones, but in the poorly transmissive zones, there is little continuity of connection in the system. At Fuente Mayor spring the differences in these zones are not so apparent and a gradual trans ition occurs. However, at La Villa spring, the karst aquifer is eviden tly much more homogeneous and the discharge is similar to that of a po rous intergranular aquifer.