Water Quality Assessment for Organic Matter Load in Urban Rivers Considering Land Use Dynamics

There has been an increasing number of global model studies that relate water quality to the watershed land use. The strategy of considering a model that is comparable to the Soil Conservation Service Curve-Number method that employs land use maps to estimate the effects of land use on the water quality, has considerable potential for application. In this context, this paper presents the LUPC (Land Use Pollutant Contribution) Model that relates pollutant loads originated by several types of coverage and a weight function which determines the load decay through water basin. It makes an estimate of the watershed features that are produced by conducting an analysis of the river profile, which is shown here in terms of the labile and refractory organic matter (OM), differentiated by its percentage of aromaticity. The initial results which were obtained by applying the model in a river basin located in the south of Brazil, suggest that the model can estimate the load of OM at a point of interest in the river and has proved to be a valuable tool for enabling managers to make decisions about the use planning land use and its impacts for water resources planning and management.