, 2010) The drought and wetness hydrological behavior reproduced

, 2010). The drought and wetness hydrological behavior reproduced by the linear combination of the first components of PCA applied to SPI field at scale of 18 months is considered satisfactory since, in almost the totality of the NEA, the proportion Selleck BMS354825 of the total variance explained at each grid point was higher than 60%. The implementation of SSA allowed us to find a common oscillatory cycle for SPI and drought/wetness spatial coverage series with a dominant period of about 6.5 years, both for dry and wet events, so we could infer that EPE, in spatial extent and in intensity have the same leading periodicities. Consistently with

these results, Krepper and Garcia (2004) reported a cycle of T ≈ 6 years in monthly precipitation series for the whole LPB and for gauging stations on the Uruguay River. Another important hydrological cycle in SPI series at 18 month time scale was the oscillatory mode with dominant period of T = 8.7 years. This result is consistent with a quasi-decadal cycle found in the annual streamflow of the Paraná and Paraguay rivers reported by García and Mechoso (2005) and Robertson and Mechoso (1998), who associated this cycle with SST anomalies

situated over the tropical North Atlantic. In addition, Venencio and García (2012) detected a similar cycle (close to 8 years) in annual precipitation in the South of the province of Santa Fe. As could Linsitinib purchase be expected, extremely dry and wet periods that affect the largest areas of the NEA, considering the percentage of grid points that exceed the thresholds of extremely wet or dry months, were the same as those showing EPE of higher intensity and duration according to the temporal behavior given by SPI field at different time scales. The analysis of historical events with large portions of the entire region under water excess/deficit at critical months enabled us to determine the most vulnerable zones to

extreme drought/wetness. The implications of these results depend on which time scales are used. The shorter scales (n = 6 months) provide valuable information for decision-making in livestock and crop production, while the longer period time scales (n = 12 or 18 months) describe the hydrological behavior of the region. The exploration at all time scales Coproporphyrinogen III oxidase indicates that the Central-West portion of NEA seems to be the most vulnerable area to extraordinary extreme drought/wetness. We have presented the spatiotemporal behavior of EPE observed throughout the 20th century and up to the year 2010 in the NEA. Dry and wet events were characterized by means of the SPI applied to monthly precipitation series at different time scales (6, 12 and 18 months). Given that the stations in NEA are not homogeneously distributed in space we used gridded precipitation datasets on high-resolution. The dataset CRU TS 3.

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