The Catchment Land Use For Environmental Sustainability Model

1857 Words Oct 10th, 2016 8 Pages
The Catchment Land Use for Environmental Sustainability model (CLUES), designed by the National Institute of Water and Atmospheric Research Ltd (NIWA), provided the data for both the Nitrogen and the Phosphorus concentrations throughout New Zealand. The development of CLUES was through a consolidation of existing mapping procedures and modelling(EnviroLink, 2012), and contributed to by various research organisations (NIWA, 2016). From this collaboration, the models responsible for the Nitrogen and Phosphorus concentrations are: OVERSEER®; the Soil Plant Atmosphere System Model (SPASMO); and Spatial Regional Regression on Watershed Attributes (SPARROW). The CLUES model calculates annual mean nutrient concentrations, based on the statistical relationship between the estimated mean average annual river flow, and the mean annual simulated load from the hydrological database recorded in the CLUES model (Woods, Hendrikx, Henderson, & Tait, 2006).
The CLUES model accesses the annual median concentrations of Nitrogen and Phosphorus, using the modelled mean nutrient load and mean annual flow rate to determine flow-weighted concentrations. CLUES then converts these figures into median concentrations, by means of a conversion ratio of mean to median flows; which is attained from regressions calculated against catchment characteristics (Oehler & Elliott, 2011). Correspondingly, a ratio of the mean annual fluctuation ascertains the variation of Annual Mean Nitrogen Concentrations in…

Related Documents