FOSFOROMSÄTTNING INOM HÖRBYÅNS AVRINNINGSOMRÅDE / Phosphorus Turnover in the Watershed of the River Hörbyån
Lake Ringsjön in Scania, southern Sweden, has been very eutrophicated during a comparatively short time. In spite of advanced municipal waste water treatment for phosphorus removal, no improvements have been observed in lake water quality. The reasons are release of P from the sediments and an extremely large external loading on two of the basins of the lake. Before internal restoration measures can be taken, the external P discharges must be reduced. In this study, a detailed analysis of P turnover has been performed in the watershed of the river Hörbyån, which discharges its water in the greatest and central basin, Lake Eastern Ringsjön. The catchment area of the river Hörbyån is an intensive agriculture area. Cropped lands and pastures cover about 50 % or 14,750 ha. Of the population, 6,000 are living in urban areas and 3,000 in rural districts. The aim of this paper was to illustrate sizes of pools and annual flows of P in an area where non-point sources dominate the discharges. “Complete abstract not presented.”