Assessing nitrate groundwater hotspots in Europe reveals an inadequate designation of Nitrate Vulnerable Zones

Monitoring networks show that the European Union Nitrates Directive (ND) has had mixed success in reducing nitrate concentrations in groundwater. By combining machine learning and monitored nitrate concentrations (1992–2019), we estimate the total area of nitrate hotspots in Europe to be 401,000 km2, with 47% occurring outside of Nitrate Vulnerable Zones (NVZs). We also found contrasting increasing or decreasing trends, varying per country and time periods. We estimate that only 5% of the 122,000 km2 of hotspots in 2019 will meet nitrate quality standards by 2040 and that these may be offset by the appearance of new hotspots. Our results reveal that the effectiveness of the ND is limited by both time-lags between the implementation of good practices and pollution reduction and an inadequate designation of NVZs. Significant improvements in the designation and regulation of NVZs are necessary, as well as in the quality of monitoring stations in terms of spatial density and information available concerning sampling depth, if the objectives of EU legislation to protect groundwater are to be achieved

DEPIVOT: a model for center-pivot design and evaluation

Available at SciVerse ScienceDirectCenter-pivot sprinkler irrigation became very popular. Hence, aimed at farmers advising, the simulation model DEPIVOT has been developed with the objective of design new systems or changes in systems in operation. The software consists of a simulation package developed in Visual Basic and data base in Access. The model comprises five main sub-models for: (a) computation of the gross irrigation requirements; (b) sizing of the lateral pipe spans through the hydraulics computation of the friction losses and respective operative simulation considering to the effects of topography and the possible requirements of an end gun; (c) selecting a sprinklers package with computation of pressure and discharge at each outlet and including the consideration of pressure regulators; (d) verification of the sprinklers package through estimation of runoff potential by comparing application and infiltration rates at selected locations along the lateral; and (e) estimating the expected uniformity performance indicators when in operation. The user verifies if performance is within target values set at start and may develop and compare alternative sprinkler packages until appropriate conditions are obtained. When the model is used for evaluation of systems under operation using data collected in farmers’ fields performance indicators are computed and, responding to farmers’ needs, the model may be used to design changes in the existing systems and to improve management. This paper describes the model and shows examples of applications to select a sprinkler package and assess the respective runoff potentia

DEPIVOT: a model for center-pivot design and evaluation

Available at SciVerse ScienceDirectCenter-pivot sprinkler irrigation became very popular. Hence, aimed at farmers advising, the simulation model DEPIVOT has been developed with the objective of design new systems or changes in systems in operation. The software consists of a simulation package developed in Visual Basic and data base in Access. The model comprises five main sub-models for: (a) computation of the gross irrigation requirements; (b) sizing of the lateral pipe spans through the hydraulics computation of the friction losses and respective operative simulation considering to the effects of topography and the possible requirements of an end gun; (c) selecting a sprinklers package with computation of pressure and discharge at each outlet and including the consideration of pressure regulators; (d) verification of the sprinklers package through estimation of runoff potential by comparing application and infiltration rates at selected locations along the lateral; and (e) estimating the expected uniformity performance indicators when in operation. The user verifies if performance is within target values set at start and may develop and compare alternative sprinkler packages until appropriate conditions are obtained. When the model is used for evaluation of systems under operation using data collected in farmers’ fields performance indicators are computed and, responding to farmers’ needs, the model may be used to design changes in the existing systems and to improve management. This paper describes the model and shows examples of applications to select a sprinkler package and assess the respective runoff potentia