An Integrated Hydrochemical Approach to Deduce the Response of an Aquifer System During Its History of Abstraction

The investigation of the regional flow characteristics of aquifers is important with respect to aquifer management. To determine regional flows, use can be made of hydraulic and hydrochemical data. In a study of a Chalk Aquifer System in the south of Lincolnshire, England, a combined hydrochemical approach using major, minor and isotope chemistry is described. The chemical data have been used because hydraulic information is difficult to interpret both locally and regionally as a consequence of multi-layered hydraulic zones, nonhomogeneous fissure zones, and variable erosional features. By characterizing ground-water types on the basis of major ion chemistry, and subsequently interrelating with minor ion distributions (notably iodide supported by strontium), a reasonable assessment of operative flow paths and mechanisms has been made. Substantiation of the conclusions reached using major and minor ion chemistry is provided by the environmental isotope data of carbon and tritium.