Vulnerability, resilience and adaptation of societies during major extreme storms during the Little Ice Age

This manuscript reviews more than 19691 French historical documents from 14 French archive centers. To assess data from historical documents, a method has been applied that leads to a record of 101 extreme storms with damage, including 38 coastal floods. Thus, the results show periods of increasing and decreasing storminess frequency. These periods are questioned. 10 Furthermore, coastal hazards have forced societies to adapt and develop some specific skills, lifestyles and coping strategies. This paper analyses some responses of past societies to these hazards. By doing so, useful ideas may be (re)discovered by today’s communities in order to enhance the ability to adapt and develop resilience. Similarly, a thorough knowledge of past meteorological hazards may allow our societies to recreate a link with territory, particularly 15 through the (re)construction of an effective memory of these phenomena.

documentary sources allows the historical reconstruction of storms within a defined temporal and spatial frame.
Fundamentally, the process of reconstruction is nevertheless difficult: some limits to the storm 130 reconstruction work must be taken into account and discussed. First, as explained in the results section below, storms recorded in historical documents are ones with major impacts, even if climatologically speaking these are not necessarily the most violent events. It is therefore obvious that for many of these hazards, the historical climatologist has no information and even no clue they happened. In these circumstances, the reconstruction is somewhat biased. Secondly, the series 135 of storms recorded in the West of France are discontinuous owing both to an oral tradition (Sarrazin, 2012) and many documentary gaps (Athimon, 2017). They are due to historical contingencies such as archival disasters 2 , the French Revolution 3 , wars such as the Hundred Year War against England in the XIV th -XV th centuries, the religious wars between Protestants and Catholics in the XVI th century; the Second World War etc. The loss of these documents certainly 140 deprives the searcher of precious censuses of wind hazards. These first two limitations make any reliable appreciation of the recurrence of storms difficult. Moreover, today's satellite images allow precise delineation of the wind direction, the trajectory of a storm and the flooded areas, during medieval times a precise spatial demarcation is impossible to establish, mainly due to a lack of information, documentations and instruments. Finally, the descriptions are often either exaggerated 145 or undervalued, which makes the characterization and the intensity estimations of a phenomenon difficult to undertake for the XIV th -XVIII th centuries.
Despite these limitations, through an acute critical study of documents, selection criteria of data and cross-checking, the historical climatologist can identify and characterize noteworthy storms and sea floods of the past. 150

Reconstruction of past storms
With 19691 documents studied from XIV th to XVIII th c., this research is the most exhaustive work done on storms and storms causing coastal flooding during the LIA on the French Atlantic coast.
138 storms were identified from the beginning of the XIV th century to the end of the XVIII th century. 155 However, due to the application of the strict criteria presented above, the final list of these phenomena is not as high in number and only 101 occurrences could be selected. Figure 2 establishes a trend of increased and decreases storm activity. As can be seen, for instance, the late XVI th century shows an intense stormy period. This period of cooling between 1560/70-1630/40 is well-known by historical climatologists and has been named the "Second Hyper LIA" 160 (Lamb, 1980;Le Roy Ladurie E., 2004). Similarly, the first twenty years and the end of the XVIII th century seem to stand out (Lamb and Frydendahl, 1991). These periods of increased frequency of storms also exist in the North Sea (Gottschalk, 1971(Gottschalk, , 1975(Gottschalk, , 1977Lamb, 1980;Lamb and Frydendahl, 1991;De Kraker, 2013). However, the question of whether or not and of the reasons why some periods experienced more storms than other is still discussed (Soens, 2018) : is it due to 165 temperature variations ? the NAO ? inter-annual to multi-decadal variability ? an increase in human stakes leading to more and more damage, so more and more historical records ? a larger number of historical documents for some centuries ?... In fact, owing to the absence of documents this figure is not exactly representative of the reality of the storms studied in the space-time frame, especially for the earlier periods. Furthermore, Aunis, particularly Ré island, as same as the area on 170 During the medieval and modern periods, no overall or itemized records on the economic or human toll were provided after a climate event by the different institutions (urban, seigniorial, and 220 royal). This can be explained as much by the thinking of the day -the very notion of a human toll was unknown, as by the authorities' lack of organisation, the poor administrative procedures, and other means available. A general estimation of the economic and human cost of storms is therefore unrealizable. For a limited spatial framework such as property, salt marshes, a fifedom, a town district, etc. accurate and reliable information on the amount of human (cf. supra), material or 225 economic losses or on the cost of repairs can nevertheless be made available. Thus, in 1469 or Damage was so severe that almost 15 years later, in the middle of the 1360's, salt production had 235 still not been re-established (Mollat, 1983).
Where possible -depending on the data stored in historical documents -, the study of past storms and their impacts must be followed by an analysis of societies' reactions and responses to these kinds of extreme meteorological hazards. The question of past societies' vulnerability, their adaptation and resilience is of huge importance. This appears to be the new focus of interest for 240 historical climatologists (Pfister, 2010).

Societies' reactions and responses
Constantly living with the risk of storms and sea floods, coastal societies have developed significant risk awareness, an effective memory of these extreme meteorological hazards, a specific way of life, a particular perception of natural hazards and risks. These elements are part of 245 a mental coping ( fig. 4). They are of relevant importance in terms of societies' reactions to storms and sea flood as can be seen in figure 4. In fact, storms and sea floods were part of the culture and habits of past coastal societies, who were used to dealing with them and considered them a normal 5 The destruction of these salt heaps is either due to the storm with sea floods on 27-28 th of January (5 th -6 th February) 1469(n.st) or an unknown event which occurred between the end of the spring and the beginning of the summer of 1470.
part of life. This is precisely what enabled them to fix memory and develop some specific knowledge. The most destructive, traumatic or atypical storms and sea floods were preserved in 250 their collective memory. The preservation and dissemination of these memories over a long period developed risk awareness among ancient societies. In 1627, inhabitants in Bouin sent a petition to king Louis XIII in which they certified having suffered from more than 15 storms and coastal  fig. 4. They are small, around two meters high, and made up of clods of clay, sand, wood and pebble (Sarrazin, 2014). Leaky and fragile, they are easily destroyed but are useful coastal defences. Moreover, their structure makes them very easy and quick to repair. Unlike the 280 Netherlands (Soens, 2009) or England (Galloway, 2009), on the French Atlantic coast no real authority interferes in dike construction (Sarrazin, 2014). Dyke construction and maintenance relies either on owners of lands and salt marshes or, if they are public, on the community (Sarrazin, 2014). In 1492-1493(n.st.), some dykes broke under sea and wave pressure on the island of Noirmoutier. Their restoration cost was modest for lord La Trémoïlle, owner of these dikes (AN 285 Pierrefitte-sur-Seine, 1 AP 1964). These low cost are mostly due to the abundance of cheap labor.
However, sometimes the cost is exorbitant. For example, in a document dating from the 7 th of December 1663, David Tessier and his wife, Janne Jumel inhabitants of Croisic, near Guérande, state that they had to restore their marsh dykes following a violent storm on January the 12 th -13 th 1663. These repairs cost more than 6000 livres (AD L-A., B 655, f°277)! 290 The vulnerability management of past coastal societies is mainly based on a precise social and work organization. Everyone (lords, farmers, fishermen, salt producers etc.) has a specific role to play. Everyone's involvement in the construction/repair of dikes and territory management develops risk awareness and ensures its dissemination within society (Sarrazin, 2014). The risks are then perfectly integrated into the coastal societies' conception and lifestyle (Galloway, Potts, 295 2007). Therefore, the vulnerability of coastal societies, in particular salt producing ones, is scaled down. Furthermore, during the late Middle Ages and modern period, dikes are built in a subdivision system. In other words, it is an intricate network of levees. Next to Anse de l'Aiguillon, a map of Champagné swamps drawn by André Chevreux in 1656 (AD Vendée, 1 E 442) presents this spatial subdivision. Dikes follow each other in a quasi « sequential » order: the 300 newest are erected on the seafront, while the older ones are further back. This technique is part of a preventive approach (Athimon et al, 2016). When the sea floods, it encounters a multitude of small levees which absorb the wave energy and break the speed of waves, lessen the intensity of flooding and reduce the spread of the water. In fact, populations were aware of the importance in maintaining levees, including the older ones, as noted in a Champagné's seigniorial court 305 document of the 7 th of November 1560 (Médiathèque de Niort, fonds La Fontenelle de Vaudoré -Clouzot, 1904;Sarrazin, 2014). Finally, the construction, development, maintenance and repair of dikes are part of the lifestyle and the culture of coastal societies. They are also connected to a notion of anticipation of future damage and risk prevention (Athimon et al, 2016).
It was not until the late XVIII th century that the royal authority becomes a systematic reference in 310 the case of an extreme hazard (Favier, 2002). However, at the end of the Middle Ages and during the whole modern period, French kingdom authorities' interference gradually increases (Athimon et al., 2016). A range of societies' reactions and responses to meteorological disaster are seen in figures 4 and 5. Figure 5 shows that the first to react to a disaster is the local population followed