Basins of various sizes have been compared to examine behaviour patterns of chemical and hydrological parameters under different geological and climatic conditions. Data from small forested basins up to 1 km², middle sized river systems up to 10 000 km², and several stations on the River Rhine below Lake Constance were used. Basins were investigated with varying degrees of sampling intensity, depending on size and the immediate aims of the particular study. In general the major physical parameters were recorded continuously, and chemical parameters were determined for continuous composite samples from large basins. Frequent grab samples were taken in smaller basins. The basic sampling regime permitted the examination of annual periodicity in fluctuations. The variance of dissolved loads in streams and rivers is markedly reduced when data evaluation includes consideration of the annual cyclic pattern. In the present study this behaviour has been identified for a number of parameters, and annual patterns are similar for small and large basins. The recognition of basinindependent patterns aids comparison of data from basins varying in size and other characteristics.