Nonpoint pollution in Aragón: emission loads and control issues

Abstract

This paper evaluates nitrogen pollution loads from irrigation return flows in the Spanish region of Aragon. Percolation and nitrogen leaching estimates are found for each municipal area based on crop surface, irrigation systems, climate, and crop management data. Aggregate nitrogen discharges at watershed and county level are then calculated and compared with results published in monographic studies and nitrate concentrations in watercourses. This paper aims to contribute to future proposals of the Water Framework Directive for nitrate pollution abatement measures. The relevance of this issue is increased by the fact that the Ministry of the Environment and various ecological organizations are under the false impression that diffuse pollution can be solved by raising water prices. Water pricing is in fact highly inefficient and severely prejudices the interests of farmers, and is thus the least desirable of all potential instruments for the control of diffuse pollution