SWAT is the product of over 40 years of research and is subject to ongoing development. The model is designed to simulate the effects of changes in land management practices, land use and climate on surface water and groundwater quality and quantity, sediments, nutrients,...

INCA-N operates at a daily time step, tracking the stores and fluxes of water, nitrate and ammonium in both the land and in-stream phases of a river catchment. The model is spatially ‘semi-distributed’: the water course is split into reaches with associated sub-catchments....

QUESTOR represents a river as a series of river reaches within which physical, chemical and biological processes operate.. The initial selection of reaches is based on the location of confluences, diffuse (catchment) sources, discharge points, abstraction points, monitoring...

SAGIS was developed for UKWIR, with support from the Environment Agency, SEPA and Natural England, to analyse sources of chemicals at the river basin scale and identify measures to improve river, lake and estuary water quality. National data on the source of chemicals...