Predicting Land-Based Nitrogen Loads and Attenuation in the Rangitikei River Catchment – the model development

We investigated and developed a simple model to account for the influence of different soil types and underlying geology on the transformation of nitrogen (N) in the Rangitikei River catchment. The main soil and rock types of the catchment were classified into low, moderate and high N attenuation capacities then assigned nitrogen attenuation values in order to predict soluble inorganic nitrogen (SIN) loads to the river. The prediction of SIN loads in the river was improved by incorporating the spatial effects of both of the different soil types and underlying geologies on N attenuation in the subsurface environment of the Rangitikei River catchment.