This module explores biogeochemical processes at the catchment level, with reference to the broader context of global climate and land use change. Major themes include interactions among the biogeochemical cycles; the linkages of biogeochemistry with sediment dynamics and hydrological processes and; climate change and land use effects on biogeochemical processes in floodplains, rivers and estuaries. The module introduces methods of field sample collection and laboratory analysis; and approaches to controlling pollutants, nutrient levels and greenhouse gas emissions in aquatic systems.