Estudio de las tendencias de la precipitación y sequías en la cuenca del Guadalquivir desde 1961

Abstract

Monthly precipitation mean areal totals for the Guadalquivir basin since 1961 have been searched for trends in 30 year periods and for periods ending in 2023, both in precipitation and drought based on the SPI index. For the yearly totals the complete series show a significant decreasing trend (p-value 1%) since 1961 of 28.6 mm/10 years, but the subseries going to the end and starting at ten year intervals (table 2) show no more significant trends, but all with negative sign. The subseries 2001-2023 has by far the lowest signed trend value (- 78.5 mm/10 y). Figure 1 shows that the years since 2010 accumulate a considerable amount of first and secord quintile years, with 2023 being the second lowest precipitation value, the lowest being 2005. The contrast between the humid 20 first year and the dry 20 last is also quite evident from the figure.