Downward flow, water quality and nitrogen loss in a small agricultural basin.

摘要

The water quality in the Longhirola basin in the province of Mantua in northern Italy was monitored between September 2002 and November 2003. In the last 4 months of 2002, the total rainfall was 262 mm, from 10 January to the end of March 2003 it was 19 mm, in the month of April it totalled 80 mm, between May and August it was 67 mm, in September it was 12 mm and in October and November it was 64 and 86 mm respectively. In spite of the excessive rainfall during the investigation, the water in the basin met drinking water standards (11 mg nitrogen/litre).