MASAS - A USER-FRIENDLY SIMULATION TOOL FOR MODELING THE FATE OF ANTHROPOGENIC SUBSTANCES IN LAKES

MASAS is a computer simulation tool to investigate anthropogenic organ ic compounds in lakes. Models included are based on a dynamic one-dime nsional vertical lake model describing the time-dependent concentratio n of a compound in the water column and in the sediment. Provision of data is ensured by library files. Interactive specification of transpo rt and transformation processes yields models of different complexity, suitable for the initial assessment of chemicals and for chemodynamic studies. A hypothetical spill of an insecticide (disulfoton) serves a s an illustration. Aspects relevant to the development of user-friendl y software in the environmental sciences are discussed. User-friendlin ess is found to depend more on program concepts than on a particular u ser interface. The management of data sets on lakes and compounds, and the implementation of transport and transformation processes in MASAS exemplify the significance of modularization, program data structures , the use of metaphors, and the distinction between automatic and user -controlled program functions.