A nonparametric spatio-temporal approach for multiple CUSUM charts of evapotranspiration

In recent years, the interest in natural resources management is increased. In this context, control charts, developed to monitor and maintain quality in industrial processes, are a useful monitoring and decision tool. In this paper, the behavior of an agro-metereological variable, named evapotranspiration, in an area of the northern part of Italy during a 25-year span (from 1992 to 2016) is studied through a nonparametric spatio-temporal geostatistical analysis and multiple CUSUM control charts. In particular, the probability that the variable registers an “out of control” is estimated over the area of interest, for three decades from the 10th to the 30th of January 2017.