Keywords
nitrate pollution on groundwater bodies, wfd objectives, water balance model, large river basins
Start Date
1-7-2012 12:00 AM
Abstract
Nitrate pollution in groundwater (GW) is a major problem in European Union that also affects a large number of GW bodies in Spain. The Spanish Ministry of Environment, and Rural and Marine Affairs has defined environmental objectives for each GW bodies of Spain in relation to pollution by nitrates, for water planning horizons, 2015, 2021, 2027. These objectives have been made available to the Spanish River Basin Authorities (RBAs) to support the elaboration of River Basin Management Plans established by the European Water Framework Directive (EC, 2000). The definition of nitrate concentration objectives in the groundwater bodies has been performed by means of the construction of a distributed hydrological model with water quality for all Spanish territory, using the Patrical model. The effect of three fertilizer application scenarios on nitrate concentrations has been assessed with this simulation model: 1) baseline scenario that corresponds to maintain the current fertilization; 2) optimal scenario, which is the application of the nitrogen optimal dose that requires a strong economic investment through the application of techniques such as fertigation; 3) trend reversal and improvement scenario that is an intermediate stage between the two previous ones, which includes the development of the action plans defined in current vulnerable areas and it is the more plausible scenario in the short to medium term. The results obtained and provided to RBAs are: the GW bodies that will reach the objective in the year 2015, when nitrate concentration is lower than 50 mgNO3/l in that year and also do not have a growing trend; the GW bodies that require extended deadline until 2021 or 2027; and the GW bodies that need to establish less stringent objectives, due to that is not possible to obtain a nitrate concentration lower than 50 mgNO3/l in 2027, even with the implementation of fertilizer optimal doses.
Definition of environmental objectives in relation with nitrate pollution in the aquifers of Spain. Simulation model and scenarios used.
Nitrate pollution in groundwater (GW) is a major problem in European Union that also affects a large number of GW bodies in Spain. The Spanish Ministry of Environment, and Rural and Marine Affairs has defined environmental objectives for each GW bodies of Spain in relation to pollution by nitrates, for water planning horizons, 2015, 2021, 2027. These objectives have been made available to the Spanish River Basin Authorities (RBAs) to support the elaboration of River Basin Management Plans established by the European Water Framework Directive (EC, 2000). The definition of nitrate concentration objectives in the groundwater bodies has been performed by means of the construction of a distributed hydrological model with water quality for all Spanish territory, using the Patrical model. The effect of three fertilizer application scenarios on nitrate concentrations has been assessed with this simulation model: 1) baseline scenario that corresponds to maintain the current fertilization; 2) optimal scenario, which is the application of the nitrogen optimal dose that requires a strong economic investment through the application of techniques such as fertigation; 3) trend reversal and improvement scenario that is an intermediate stage between the two previous ones, which includes the development of the action plans defined in current vulnerable areas and it is the more plausible scenario in the short to medium term. The results obtained and provided to RBAs are: the GW bodies that will reach the objective in the year 2015, when nitrate concentration is lower than 50 mgNO3/l in that year and also do not have a growing trend; the GW bodies that require extended deadline until 2021 or 2027; and the GW bodies that need to establish less stringent objectives, due to that is not possible to obtain a nitrate concentration lower than 50 mgNO3/l in 2027, even with the implementation of fertilizer optimal doses.
