Drought in Spain in the past 500 years

A Spanish research group reconstructed drought cycles in this country between 1506 and 1900 based on a record of rituals stored in Toledo cathedral, aiming to observe the drought change. in the last 500 years. Short-term meteorological data and tree growth rings are also used to complement these records.

Historical documents such as records of the rogativas (agricultural rituals of Roman origin) were compiled at Toledo Cathedral and town churches, allowing scientists to gain an understanding of Climate learning period between 1506 and 1900 in Toledo and Madrid, especially severe weather events such as drought.

After clarifying this information, scientists published their research in Global and Planetary Change. Their article shows that drought in Spain in most of the 16th century was less frequent and shorter than in later periods.Typical for the period from 1676 to 1710 is low hydrogen pressure, and drought in the 19th century is also quite rare.

However, 'the most severe droughts were recorded from the late 16th century to the 18th century' , Juan I. Santisteban. One of the authors of the study and scientist at the Complutense Madrid University (UCM), said.

Scientists found that 'droughts occur more frequently and more severely in other periods at the center of the peninsula during the Little Ice Age, the period including the period studied. Although the level of drought is equivalent to today, research cannot determine whether droughts today are longer than previous droughts. Santisteban said: 'Today's great demand for fresh water makes water shortage worse.'

Toledo Cathedral. (Photo: José María Cuellar (Creative Commons))

The study also compares these results with those from other records in the Mediterranean region. Santisteban explains: 'Significant differences are observed between the frequency and length of droughts - we find periods of heavy rains and droughts at the same time in different regions. of the Iberian Peninsula as well as the differences between the North and the South '.

A meta-analysis of information on drought and air pressure - conducted by researchers from UCM, Spanish Institute of Geological Mining, and University of Barcelona - shows regular periods of drought. match the positive stages of the North Atlantic, creating a windless climate condition at Azores. However, they also added that the 'topography of the Iberian peninsula may be the cause of the inconsistency of the drought phenomenon'.

The church monitors the climate

Rituals held at Toledo Cathedral are strictly controlled by a number of church laws, and are quite diverse according to meteorological conditions. In Spain, the cathedral's historical documents provide continuous records since the 16th century.

The rogativas data is analyzed by scientists from three sources - 121 church books recorded from Toledo Cathedral, which records daily life from 1466 to 1599, the book by Juan Bautista de Chaves Arcayos ( who summarized documents from 1434 to 1599 and added updates of himself), and 311 church books (1464-1914).

The series of rogativas rituals include 341 people praying for rain, 36 people praying for favorable weather and 94 groups thanking (rituals to congratulate the end of the mandatory climatic phenomenon for rogativa ). Many rogativas are part of the spring ritual.

Refer:

1. Domínguez-Castro, Fernando;Santisteban, Juan I .;Barriendos, Mariano;Mediavilla, Rosa.Reconstruction of drought episodes for central Spain from the recording ceremonies at the Toledo Cathedral from 1506 to 1900: A methodological approach.Global and Planetary Change, 63 (2-3) Sp.Iss.SI: 230-242 SEP 2008