NITRATE POLLUTION OF THE LESNOVSKA RIVER CAUSED BY FILTRATION OF CHEMICALS BY AGRICULTURAL AREAS

Abstract

The nitrate pollution caused by filtration of chemicals from agricultural areas is a subject to a number of studies during the last decade. The main purpose of this study was to specify the river flow (Q, m³/s), nitrate concentrations and conductivity in a part of the Lesnovska River Basin, situated near the Sofia City, the capital of Bulgaria. Incoming flow (Q, m³/s) by filtration in to the river and evaluation of the contaminated with nitrate water quantity were defined by means of balance methods, based on the results from the precise performed measuring. The main tasks of the study were verification of the mathematical model of the nitrate pollution formation in the river terraces groundwater and to define the contribution of this contamination in to the river. Thus, the affects of fertilizing on agriculture areas and on the river water quality were determinate on the basis of information about the quantity of the nitrate pollution coming from the groundwater and by filtration (Q, m³/s).