The management of hydrological extremes and impacts on society is inadequately understood because of the combination of short-term hydrological records, an equally short-term assessment of societal responses and the complex multi-directional relationships between the two over longer timescales. Rainfall seasonality and interannual variability on the Pacific coast of Central America is high due to the passage of the Inter Tropical Convergence Zone (ITCZ) and large-scale phenomena El Niño Southern Oscillation (ENSO). Here we reconstruct hydrological variability and the associated impacts drawing on documentary sources from the cities of Santiago de Guatemala (now Antigua Guatemala) and Guatemala de la Asunción (now Guatemala City) over the period from 1640 to 1945. Near continuous records of city and municipal council meetings provide a rich source of information dating back to the beginning of Spanish colonisation in the 16thC. Beginning in 1640, we use almost continuous sources, including >&thinsp;190 volumes of <i>Actas de Cabildo</i> and <i>Actas Municipales</i> (minutes of meetings of the city and municipal councils) held by the <i>Archivo Histórico de la Municipalidad de Antigua Guatemala</i> (AHMAG) and the <i>Archivo General de Centro América</i> (AGCA) in Guatemala City. For this 305-year period (with the exception of a total of 11 years where the books were either missing or damaged), information relating to Catholic rogation ceremonies and reports of flooding events and crop shortages, were used to classify the annual rainy season (May to October) on a 5 point scale from very wet to very dry. In total 12 years of very wet conditions, 25 years of wetter than usual conditions, 34 years of drier conditions and 21 years of very dry conditions were identified. An extended drier period from the 1640s to the 1740s was identified as well as two shorter periods (the 1820s and the 1840s) dominated by dry conditions. Wetter conditions dominated the 1760s&ndash;1810s, possibly coincident with reconstructions of more persistent La Niña conditions that are typically associated with higher precipitation over the Pacific Coast of Central America. The 1640s&ndash;1740s dry period coincides with the onset of the Little Ice Age and the associated southward displacement of the ITCZ.
Guevara-Murua, A., Williams, C. A., Hendy, E. J., & Imbach, P. (2018). 300 years of hydrological records and societal responses to droughts and floods on the Pacific coast of Central America. Climate of the Past, 14(2), 175–191. https://doi.org/10.5194/cp-14-175-2018