Abstract. The use of documentary evidence to investigate past climatic trends and
events has become a recognised approach in recent decades. This contribution
presents the state of the art in its application to droughts. The range of
documentary evidence is very wide, including general annals, chronicles,
memoirs and diaries kept by missionaries, travellers and those specifically
interested in the weather; records kept by administrators tasked with keeping
accounts and other financial and economic records; legal-administrative
evidence; religious sources; letters; songs; newspapers and journals;
pictographic evidence; chronograms; epigraphic evidence; early instrumental
observations; society commentaries; and compilations and books. These are
available from many parts of the world. This variety of documentary
information is evaluated with respect to the reconstruction of hydroclimatic
conditions (precipitation, drought frequency and drought indices).
Documentary-based drought reconstructions are then addressed in terms of
long-term spatio-temporal fluctuations, major drought events, relationships
with external forcing and large-scale climate drivers, socio-economic impacts
and human responses. Documentary-based drought series are also considered from
the viewpoint of spatio-temporal variability for certain continents, and
their employment together with hydroclimate reconstructions from other
proxies (in particular tree rings) is discussed. Finally, conclusions are
drawn, and challenges for the future use of documentary evidence in the study
of droughts are presented.
Documentary data and the study of past droughts: a global state of the art