TRANSPORT OF NIROGEN, PHOSPHORUS, AND SILICON VIA GROUNDWATER INTAKE IN THE YODO RIVER BASIN

Abstract

 To maintain a healthy circulation system in coastal areas, the inflow load balance of nutrients including nitrogen, phosphorus, and silicon must be properly controlled. This study collects and analyzes the amount of water intake and water quality data of water purification plants, which intake groundwater in the Yodo River Basin, and calculates the amount of nutrients transported via groundwater intake to quantitatively evaluate the nutrient dynamics in the basin.

 Thus, the water quality distribution characteristics of the groundwater differed among water quality items, and silicon showed high concentrations in deep wells in the lower Yodo River Basin. Additionally, 10%–15% of the amount of silicon transported through the river under ordinary water level conditions was derived from the groundwater intake at the water purification plants, which had a considerable influence on the basin-scale transport.