Comparative analysis of annual and monthly peak flow tendencies, considering two periods in north-central Chile

Roberto Pizarro; Pablo García-Chevesich; Francisco Balocchi; Juan Pino; Alfredo Ibáñez; Claudia Sangüesa; Carlos Vallejos; Romina Mendoza; Ben Ingram; Jonathan O Sharp

doi:10.24850/j-tyca-13-05-03

Authors

Roberto Pizarro Universidad de Talca, Talca, Chile / Cátedra Unesco en Hidrología de Superficie, Universidad de Talca, Talca, Chile https://orcid.org/0000-0002-6601-3811
Pablo García-Chevesich Colorado School of Mines, Department of Civil and Environmental Engineering, Denver, Colorado, United States / Unesco, International Hydrological Programme, Paris, France https://orcid.org/0000-0002-9668-4560
Francisco Balocchi Bioforest SA, Coronel, Chile / Water Resources and Energy for Agriculture PhD Program, Water Resources Department, Universidad de Concepción, Chillán, Chile https://orcid.org/0000-0002-9171-2382
Juan Pino Dirección de Transferencia Tecnológica, Universidad Tecnológica Metropolitana, Santiago, Chile https://orcid.org/0000-0002-1506-7174
Alfredo Ibáñez Cátedra Unesco en Hidrología de Superficie, Universidad de Talca, Talca, Chile https://orcid.org/0000-0002-9774-5601
Claudia Sangüesa Cátedra Unesco en Hidrología de Superficie, Universidad de Talca, Talca, Chile https://orcid.org/0000-0002-3363-3424
Carlos Vallejos Cátedra Unesco en Hidrología de Superficie, Universidad de Talca, Talca, Chile https://orcid.org/0000-0002-2986-2590
Romina Mendoza Cátedra Unesco en Hidrología de Superficie, Universidad de Talca, Talca, Chile https://orcid.org/0000-0002-3206-8355
Ben Ingram Cátedra Unesco en Hidrología de Superficie, Universidad de Talca, Talca, Chile https://orcid.org/0000-0003-4557-4342
Jonathan O Sharp Colorado School of Mines, Department of Civil and Environmental Engineering, Denver, Colorado, United States https://orcid.org/0000-0002-2942-1066

DOI:

https://doi.org/10.24850/j-tyca-13-05-03

Keywords:

Peak flows trends, Mann-Kendall, climate variability

Abstract

It is essential to understand long-term trends associated with water resources in arid climates such as Chile's to prepare and predict potential adverse implications of climate change in these already water-stressed regions. Trends in annual peak flows (instantaneous maximum flows) of the Coquimbo Region were studied through the Mann-Kendall statistical test (5 % error), considering the 1984-2014 period and, in a second analysis, extending the series to at least 29 % more (1976-2014). Results indicate that for the annual peak flows, in both periods, all analyzed series showed a tendency to decrease (80 % of them significantly in the 1984-2014 period and 29 % in the 1976-2014 period). In contrast, analysis of monthly peak flows revealed a more nuanced shift where 99 % of the series tended to decrease in the 1984-2014 period, with 46 % being significant. However, in the 1976-2014 period, 74 % of series tended to decrease, but only 12 % were significant. This decline in negative and significant trends after incorporating years before 1984 suggests that these situations have occurred previously. Finally, this variation in the significance level when considering different time lengths would evidence a cyclic process that influences the behavior of peak flows.