Author(s)

A. Moratalla, J. J. Gómez-Alday & J. de las Heras

Abstract

This project determines the nitrate content as well as spatial and temporal distribution in the water supply wells which extract groundwater from the Mancha Oriental System (MOS). The underground resources of the system are used in maintaining approximately 80,000 hectares of irrigation and are the water supply for a total population of 275,000 inhabitants. The average nitrate contents show a heterogeneous spatial distribution, varying between 0.1 mg l-1 and 125 mg l-1. The highest levels are associated with areas with large areas of irrigated crops. However, there are also points that are not found to be spatially linked to this type of farming in which nitrate has been detected in significant quantities. The presence of nitrate in these areas can be explained considering other sources of pollution or transport of the pollutant from contaminated areas through groundwater flow. In general, average nitrate values show a growing tendency during the period 1998 and 2003. Keywords: nitrate, irrigated crops, groundwater, Mancha Oriental System, SE Spain. 1 Introduction The natural quality of groundwater can be observed as altered by the presence of nitrate proceeding from farming and livestock activities. In fact, the excessive application of fertilizers has been admitted as the main cause of nitrate and other

Keywords

nitrate, irrigated crops, groundwater, Mancha Oriental System, SE Spain.