Scale continuous characterisation of karst aquifers

摘要: In this work results of different field experiments for the characterization karst aquifers are compared and attributed to structural properties these systems. The important parameterizing numerical models dealing with hydraulics. A aquifer represents a dual flow system consisting low permeability fissured matrix highly permeable conduit system. Over large volume can be considered as continuum representative elementary (REV) defined. However REV is only valid on local scale. On regional scale drainage controlled by which might display anisotropic geometry. current modeling approaches simulation hydraulics therefore implemented second or discrete pipe network hydraulically coupled (Sauter et al. 2006). Classical methods characterize systems artificial tracer tests. These tests usually applied identify point-to-point connections (e.g. between sinkhole spring), determine transport parameters in estimate geometric hydraulic disadvantage method is, however, that limited information about geometry interaction achieved. Conventional borehole Slug-tests, example, deep small-diameter boreholes it often case thick unsaturated zones. However, test strongly depend location investigated displacement depth. spectrum responses may range from oscillating water levels high conductivity parts slowly responding parts. Because small integration difficult slug-tests. Larger volumes surrounding characterized applying pumping present study we consider rates several 100 l/s, allow drawdown level (Marechal al., 2008). require well directly connected Thus, at early times reflects response allows determination its properties. Late time drawdowns characteristics whole system, i.e. matrix, while intermediate show alone. Large-scale have potential scale-continuous manner single method, essential parameterization models.