Abstract
The techniques of petrological microscopy are seldom applied to hydrogeological problems although they allow the direct measurement of grain size, pore size and porosity, from which it is possible to estimate hydraulic conductivity, specific yield and solute retardation factors; information clearly valuable where direct measurement of these parameters is impossible. Further comparison of microscopically determined values with direct measurements provides a physical basis for the development of accurate conceptual models of the micro-scale processes which control groundwater flow and solute transport. During the development of a catchment—scale model of the hydrological effects of land use change, petrological microscopy was successfully used as a means of extending the database. In particular, hydraulic conductivities estimated from thin section observations showed a clear positive correlation with permeameter-derived hydraulic conductivities for the same samples.
