ADGEO Advances in Geosciences ADGEO Adv. Geosci. 1680-7359 Copernicus Publications Göttingen, Germany 10.5194/adgeo-10-51-2007 Mapping monthly rainfall data in Galicia (NW Spain) using inverse distances and geostatistical methods Mirás-Avalos J. M. 1 Paz-González A. 1 Vidal-Vázquez E. 2 Sande-Fouz P. 1 Faculty of Sciences, University of Coruña, 15071 Coruña, Spain EPS Lugo, University of Santiago de Compostela, 27002 Lugo, Spain 26 04 2007 10 51 57 Copyright: © 2007 J. M. Mirás-Avalos et al. 2007 This work is licensed under the Creative Commons Attribution-NonCommercial-ShareAlike 2.5 Generic License. To view a copy of this licence, visit https://creativecommons.org/licenses/by-nc-sa/2.5/ This article is available from https://adgeo.copernicus.org/articles/10/51/2007/adgeo-10-51-2007.html The full text article is available as a PDF file from https://adgeo.copernicus.org/articles/10/51/2007/adgeo-10-51-2007.pdf

In this paper, results from three different interpolation techniques based on Geostatistics (ordinary kriging, kriging with external drift and conditional simulation) and one deterministic method (inverse distances) for mapping total monthly rainfall are compared. The study data set comprised total monthly rainfall from 1998 till 2001 corresponding to a maximum of 121 meteorological stations irregularly distributed in the region of Galicia (NW Spain). Furthermore, a raster Geographic Information System (GIS) was used for spatial interpolation with a 500×500 m grid digital elevation model. Inverse distance technique was appropriate for a rapid estimation of the rainfall at the studied scale. In order to apply geostatistical interpolation techniques, a spatial dependence analysis was performed; rainfall spatial dependence was observed in 33 out of 48 months analysed, the rest of the rainfall data sets presented a random behaviour. Different values of the semivariogram parameters caused the smoothing in the maps obtained by ordinary kriging. Kriging with external drift results were according to former studies which showed the influence of topography. Conditional simulation is considered to give more realistic results; however, this consideration must be confirmed with new data.

 References Burgess, I. and Webster, R.: Optimal interpolation and isarithmic mapping of soil properties. I: The semivariogram and punctual kriging, J. Soil Sci., 31, 315–331, 1980. Burrough, P. A. and McDonnell, R. A.: Principles of Geographical Information Systems, Spatial Information Systems and Geostatistics, Oxford University Press, 1998. Carballeira, A., Devesa, C., Retuerto, R., Santillán, E., and Ucieda, F.: Bioclimatología de Galicia (in Spanish), Fundación Pedro Barrié de la Maza, Conde de Fenosa, A Coruña, Spain, 1983. Chilés, J. P. and Delfiner, P.: Geostatistics. Modeling Spatial Uncertainty, Wiley Series in Probability and Statistics, John Wiley and Sons, Inc. 1999. De Uña Álvarez, E.: El clima (in Spanish), in: Atlas de Galicia. Tomo 1: Medio Natural, edited by: Precedo Ledo, A. and Sancho Comíns, J., Sociedade para o Desenvolvemento Comarcal de Galicia, Xunta de Galicia, Spain, 2001. Deustch, C. and Journel, A. G.: GSLIB Geostatistical Handbook, Oxford University Press, 1992. Gómez Hernández, J. J., Cassiraga, E. F., Guardiola Albert, C., and Álvarez Rodríguez, J.: Incorporating information from a digital elevation model for improving the areal estimation of rainfall, in: geoENV III – Geostatistics for Environmental Applications, Quantitative Geology and Geostatistics, edited by: Monestiez, P., Allard, D., and Kluwer, R. F., Kluwer Academy Publishers, 67–78, 2001. Goovaerts, P.: Geostatistics for natural resources evaluation, Applied Gesotatistcs Series, Oxford University Press, 1997. Goovaerts, P.: Geostatistical approaches for incorporating elevation into the spatial interpolation of rainfall, J. Hydrol., 228, 113–129, 2000. Militino, A. F., Palacios, M. B., and Ugarte, M. D.: Robust predictions of rainfall in Navarre, Spain, in: geoENV III – Geostatistics for Environmental Applications, Quantitative Geology and Geostatistics, edited by: Monestiez, P., Allard, D., and Kluwer, R. F., Kluwer Academy Publishers, 79–90, 2001. Mirás Avalos, J. M.: Estimación y simulación de la precipitación en Galicia a escala mensual (in Spanish), Ph D. Thesis, University of A Coruña, Spain, 2003. Pebesma, E. J.: GSTAT User's Manual, Dept. of Physical Geography, Utrecht University, 2000. Samper Calvete, J. and Carrera Ramírez, J.: Geoestadística, Aplicaciones a la Hidrología Subterránea (2nd edition) (in Spanish), Centro Internacional de Métodos Numéricos en Ingeniería, Barcelona, 1996. Thonon, I. and Paz González, A.: A Geostatistically interpolated digital elevation model of Galicia (NorthWest Spain), in: GeoENV 2002, Fourth European Conference on Geostatistics for Environmental Applications, Kluwer Academy Publishers, 532–533, 2004. Van Deursen, W. P. A. and Wesseling, C. G.: The PCRaster Package, Vakgroep Fysische Geografie, Faculteit Ruimtelijke Wetenschappen, Universiteit Utrecht, Utrecht (The Netherlands), 1992. Vieira, S. R.: Geoestatística em estudos de variabilidade espacial do solo (in Portuguese), in: Tópicos em Ciência do Solo, edited by: Novais, R. F., Alvarez, V. H., and Schaefer, G. R., Viçosa: Sociedade Brasileira de Ciência do Solo, 1, 1–54, 2000. Webster, R. and Oliver, M. A.: Geostatistics for Environmental Scientists, Statistics in Practice Series, John Wiley & Sons Ltd., 2001.