Geostatistical analysis of the Gorran water protection area in Nynäshamn municipality

Abstract: Groundwater level models have an important role in the development and application of water management and policies. Understanding the temporal and spatial variations of groundwater levels in the Gorran water protection area in Nynäshamn is important for developing management strategies. Geostatistical analysis with several different methods was used to compare groundwater level records for 13 observation wells in Gorran from 1994 to 2012. The performance of the different methods was evaluated by using mean absolute error (MAE) and root mean square error (RMSE) metrics. The results showed that geostatistical methods had a higher general accuracy when utilizing the Empirical Bayesian kriging (EBK) method in Gorran. EBK was the best method with highest precision and lowest mean absolute error. Cross-validation was also applied to evaluate the best (smallest) root mean square error (RMSE). A predicted potentiometric groundwater level was estimated from the basis of the available digital elevation model to extend the observation area within the same geological specification.