Predicting sediment and nutrient loads in tropical watersheds in Puerto Rico

High and resilient sediment and nutrient concentrations in streams are precursors or indicators of stream impairment. According to recent estimates by USEPA (2001), about 40% of the monitored national water supplies do not meet quality standards to support designated uses. A similar situation is observed in Puerto Rico. The 2002 water quality inventory of Puerto Rico reports that 67% of the monitored river miles were impaired (JCA, 2002). In this study water quality parameters were sampled during the 2004-2005 water year in four sub watersheds of the Rio Grande de Arecibo watershed, located in the central part of Puerto Rico. The objective of this thesis research was to determine sediment and nutrient loads and to propose mathematical relationships to relate sediment and nutrient loads to physiographic and hydrologic properties of the sub watersheds. (Abstract shortened by UMI.)...