Characteristics of Annual River Loads

Abstract

This study evaluated the characteristics of annual river loads based on inter-annual rating curves as power-law relationships between annual specific discharge and annual specific loads. Relationships between two parameters of rating curves and land use ratio were investigated using long-term daily paired observations of water quality and discharge from nine watersheds in the United States with a variety of land use and area. The results suggested the quantitative relationship between two parameter values and land use ratio. Estimation of the inter-annual rating curve was also investigated based on long-term monthly random monitoring of water quality. Such low-frequency monitoring data can provide an accurate but imprecise estimates of inter-annual rating curves.