## 5 Conclusions  
Agriculture in New Zealand is the largest sector of the tradable economy; consequently, knowledge of the spatial distributions of rainfall in this country is essential for water resource management. In fact, New Zealand presents large spatial differences in the rainfall distribution. As an example, although the Southern Alps are one of the rainiest places in the world, the east side of the South Island often suffers from droughts. Moreover, sustainable landscape management requires spatially interpolated data, whose outcomes are strictly related to models and geostatistical parameters adopted. In this paper, in order to generate precipitation maps at monthly scale, both deterministic (inverse distance weighting) and geostatistical (ordinary kriging, kriging with an external drift, and ordinary cokriging) methodologies have been applied and the prediction performance of each method was evaluated through cross-validation and visual examination of the precipitation maps produced. Results of the cross-correlation confirmed the worse accuracy of IDW than geostatistical methods. In particular, although the COK has been identified as the best method in the interpolation of monthly rainfall in New Zealand, the visual comparison of the spatial results obtained with the different geostatistical methods evidenced similar rainfall distributions, thus demonstrating that no significant results have been achieved by adding elevation and geographical coordinates as secondary variables. Further analysis could be conducted to improve the spatial distribution of monthly rainfall by adding new secondary variables, such as wind speed or humidity. Conceptualisation, T.C. and I.G. ; methodology, G.P. and I.G. ; software, T.C. and G.P. ; validation, T.C., G.P., I.G. and G.M. ; formal analysis, T.C., G.P., I.G. and G.M. ; investigation, T.C., G.P., I.G. and G.M. ; data curation, T.C. ; writing--original draft preparation, T.C., G.P. and I.G. ; writing--review and editing, T.C., G.P., I.G. and G.M. ; visualisation, T.C. and G.P. ; supervision, T.C., G.P., I.G. and G.M. ; funding acquisition, T.C. and G.M. All authors have read and agreed to the published version of the manuscript. Funding: This research received no external funding. Institutional Review Board Statement: Not applicable. Informed Consent Statement: Not applicable. Data Availability Statement: Data and information developed in this research are available, upon any reasonable request, by emailing the authors. Acknowledgments: The authors would like to thank the National Institute of Water and Atmosphere Research for providing access to the New Zealand meteorological data from the National Climate Database. Conflicts of Interest: The authors declare no conflict of interest. References  
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