A 17th century landscape through historical maps: ArcScene visualisation

 Hello everyone!
The last couple of days I have started a small (yet unfinanced) research project aimed at applying the principles of LCA (Landscape Character Assessment) and HLC (Historic Landscape Character) in a 17th century context. While LCA and HLC is traditionally concerned with mapping the character of the present-day landscape and its historical components, this study will be based on characterising the landscape as it looked during the 17th century. This can more or less only be done in regions which were more or less entirely covered by consistent maps during the same period.
   As explained in some of my other posts, Sweden has a world-unique collection of detailed large-scale geometrical maps from the first of half of the 17th century, which shows and describes the rural landscape before the agrarian revolution of the 18th century. Sadly, only parts of Sweden are covered by this material, and the amount of available maps also varies from region to region (the regions covered by these maps can be seen here). For this study, I have therefore chosen two neighboring parishes - Blidsberg and Dalum - in the hundred of Redväg (in Västra Götaland) which were almost completely mapped during the middle of the 17th century. 
   The maps from this region were made by a surveyor called Kettil Classon (Felterus), whose maps are quite rich in detail. Among other things, the maps often give valuable information concerning the vegetation and landforms of the area. Furthermore, the parishes of Blidsberg and Dalum lie in the river valley of Ätran, where the river itself plays - and has always played - a dominant role. It seems like the surveyor payed quite good attention to the river while making his maps, as it is possible to trace the geomorphological changes through a simple comparison between the historical maps and a modern orthophoto. The extensive meadows of the regions seem also to be relatively well mapped. This is quite unique, as the surveyors usually focused on documenting the arable fields and the location of individual farms. While this in some ways may reflect the experience and capability of the surveyor in this region, it is most likely rather due to external factors affecting the mapping process, such as weather conditions.

   The natural starting point was therefore to start by georeferencing the 15 maps included in the study, in order to recreate the landscape of the 17th century in this region. As the quality  of the maps from both parishes were generally high, the rectification process mostly included between 2-3 control points on maps of high accuracy. This meant that these maps were more or less just rescaled and refitted, and the rectification kept the original measurements of the surveyor more or less intact. Where inconsistencies were found in the maps, more control points were given - in places up to 12 - in order to not distort the original measurements, especially of the arable fields.
  Still, the result is far from perfect, but only meets the general requirements of the study at hand, which is not aimed at providing highly detailed information but to provide a general picture of the landscape characteristics. In some places, adjacent maps do not fit each other perfectly. This becomes most clear when looking at the river, for which I sadly must blame the surveyor. Of course, the maps could have been given more control points in order to counteract this problem, but that went beyond the purpose of this study. 

   The combined georeferenced result was then draped over a 2 meter resolution DEM of the area, which made it possible to explore the topography of the 17th century landscape in Esri's ArcScene. This provides an excellent overview of the area, which gives a nice context to the further stages of this Landscape Character analysis.

 The ArcScene visualisation of the georeferenced result. Here it is possible to see the ways in which the rural landscape was adapted to the topography of the area. Also, notice that the 17th century river sometimes makes strange bends over contemporary hills, diverting from the present day riverbed. This might indicate an inaccuracy in the historical maps, but may also illustrate that the meandering pattern has developed over the centuries, reforming the river channel.



For the last couple of months I have been engaged in research concerning the history of two river systems in Sweden: Göta Älv and Ätran. I have tried to explore questions of river/human interaction and several interesting themes have emerged. In my research I have focused on six case studies, and this blog post concerns one of them: Åkerström.

 A map of Göta Älv with some important places marked.

For anyone interested in the history of Göta Älv – the largest river in Sweden which enters the ocean at the area surrounding Gothenburg – Åkerström is a place of significance for several reasons. The river has been used for transport for many centuries and Åkerström is intimately tied to the transport economy of Göta Älv on many levels. Furthermore, the Göta Älv valley has long been plagued by natural disasters which historical effects can be clearly seen in this area. The river should not be seen as something passive in this region, as its nature and effect upon the surrounding landscape clearly has affected the human society of the area.

  The pre-medieval history of Åkerström remains largely unknown and unexplored. The only nearby remains of Iron Age activity is an ancient hill fort on a mountain overlooking the river channel just to the northwest of the 17th century farm Slätthult. Almost no burial features can be found here, apart from a few stone settings and stone circles to the north of Åkerström. Thus it seems like the local area was pretty much uninhabited during the Iron Age.
   During the Middle Ages, the main area of settlement lay to the north of Åkerström, between present day Trollhättan and Vänersborg. This area was highly suitable for farming with soils consisting mainly of clay and silt. The vicinity to Vänern and the extensive forests surrounding this settlement area also provided the foundation for a diverse amount of secondary resource production. Cattle farming was the most important agrarian resource of this area and cattle – along with its byproducts – was highly valuable trade goods.
   It is difficult to say with any certainty to what extent this region of Göta Älv was used for transport during the medieval period. Considering the picture that emerges during later centuries it is highly likely that the whole river has been used at least sporadically for transportation during the Middle Ages. However, the falls at Lilla Edet and Trollhättan were difficult obstacles for upstream transportation, and it is perhaps more likely that Göta Älv was used for downstream transports during this period – such as timber rafting. The difficulties of these water falls are well emphasised the later development, where a road called “Edsvägen” connected the river north of Trollhättan to Åkerström. Goods where traditionally unloaded at Trollhättan and transported by land to Åkerström. From Åkerström the goods could be shipped to Lilla Edet where it had to be transshipped again – at least before the middle of the 17th century when a river lock was constructed there by King Karl the IX of Sweden. 

A georeferenced and digitised version of the 17th century map of Åkerström on top of a modern orthophoto. The original map can be seen here: Map of Åkerström (National Archives)

   Åkerström should therefore be seen as a rather liminal area up till at least the 16th century, when it first appears in the written records. When we take a look at a map of the area from 1653, the location is obviously entangled in the river economy of Göta Älv. The map mainly surveys the farms of Slätthult and Stubbered, but also shows the location of Åkerström – where some “iron huts” where located – as well as the border stream between Denmark and Sweden. In 1648 a landslide occurred in this area, which had disastrous effects on the settlements downstream. Several ships and houses were destroyed, and the earth masses blocked the entire river valley. When the water eventually broke through the dam of soil a huge “tidal wave” swept down the valley, causing severe additional damages. The location of this landslide (called “Stora Jordafallet”) is also marked on the map.

   The farms of Slätthult and Stubbered were by no means disentangled from Göta Älv, and had access to fishing waters in the river. In addition, Slätthult made “good revenues” from barges going down Göta Älv towards Gothenburg. We can only guess at the nature of these barges, but the farm obviously produced timber which would have been easily transported down the river. Timber rafting on Göta Älv was common during the 17th century, but most timber came from more distant places, such as Värmland and Dalsland. Here is then an example of a local entrepreneur who was engaged in the larger economic structures of Early Modern Sweden, and who used them for his/her own gains. We cannot know the historical depth of this phenomenon. According to some authors, timber rafting occurred on Göta Älv already during the Middle Ages. Even though this is indeed possible, scarce evidence exists.

   Perhaps even more interesting are the two abandoned sawmills which lay on the lands of Slätthult. It is highly likely that the timber industry of the area suffered from the landslide in 1648, which would explain the abandoned saw mills. No real trace of these sawmills can be seen today, as they seem buried beneath large amounts of rocks which have fallen from the slopes to the south-east. 

   That was a short account of the area of Åkerström during the Early Modern period. The place is highly interesting, and an investigation like this raises additional questions:

·         The water falls at Trollhättan were used for milling during the 15th century, which indicates that the vicinity was settled. Is it possible that the trading station of Åkerström was active already during the Middle Ages?

·         Was local private engagement in long-distance trade something common during the Early Modern period?

·         Was the area surrounding Åkerström politically important in some way due to its economic function?

·         If so, where are the physical traces of this importance located?