TEMPORAL AND SPATIAL EVOLUTION OF TOTAL DISSOLVED SOLID CONCENTRATION AND NITRATES IN GROUNDWATER FROM THE WESTERN PART OF ORADEA, ROMANIA

Groundwater is of special importance for life and especially for the quality of people's lives, and more pronounced importance in terms of global climate change, especially semi-arid and arid areas of the globe. The analysed water area is located in the western part of Oradea, on the Crisului Repede meadow, on the right bank, on both sides of the Oradea - Bors road. On this area, during the 1960s, the industrial platform of the city was developed and in the western part of this platform, a series of agro-industrial enterprises occurred. For the monitoring of groundwater quality, 11 point samples (hydrogeological drills) were located near potential polluters. The temporal evolution of the total solid dissolved (TSD) and the nitrate (NO3) concentrations for a period of 33 years (1977-2010) was analysed. The study of the spatial trends of the analysed parameters called for the GIS software, namely ESRI ArcGIS 9.3. The characterisation of underground water quality after TSD indicates the tendency to improve the situation in time and space, especially after 1990. In the case of NO3, there has been an increase since 1997, so that, in 2010, around 60% of the area exceed the maximum admissible concentration (MAC).