Integrated application of United Kingdom national river flow and water quality databases for estimating river mass loads

Temporally consistent time series of river mass loads are required to assist with the rational management of the environment (e.g., annual loads of nutrients to lakes, estuaries and coastal sea areas). Issues concerning the integrated application of the United Kingdom national databases for river flows and water quality for calculating river mass loads are discussed. The paper focuses on the range and nature of error sources in river mass load estimates and warns against assigning unrealistically high precision to river loads estimated from the national datasets. Annual mass loads from the freshwater monitored area of Great Britain, 1974 to 1994, are presented for suspended solids, "total" nitrogen (NO3-N + NO2-N + NH4-N) and zinc (dissolved and suspended).