Vostitsa: Landscape

In this episode the landscape of Vostitsa is described using GIS analyses.

See the accompanying maps and images on the companion page for this episode on the Helonaki website.

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April 5th, 1806. From Megaspilio to Vostitsa Set out at 8:20. Our road descends the mountain by a narrow zigzag path among bushes. At 8:40 cross the river by a bridge. Zachlourou is five minutes beyond a village having two small makhalas on the left bank of the river. And a third on the right. We proceed along the side of a bare mountain above the left bank. At nine quitting the river, which pursues its course northward towards the sea. Through a narrow ravine bordered by precipices. We turn to the left up a valley formed by a branch of the river. After skirting the right bank of the stream a little way. Cross it. And mount the ridge over the left bank. Leaving Dumena on the side of the opposite mountain, half a mile on the left. At 9:40 having arrived at the top of the ridge we looked down on the Corinthian Gulf. Descend and then cross another ridge. On the summit of which at 10:25, we halt five minutes. Here is a fine view of the opposite part of Rumili; Parnassus and the mountains near Solona are very conspicuous. Below us is a hollow of cultivated land and pasture, with small streams running into the Kalavryta river, which is at no great distance on the right. Proceed along the side of the hill and halt five minutes at a fountain. Eight minutes beyond, I arrive at 11 at the site of an ancient town. It stood on the lowest part of the ridge which separates the course of the feeders of the Kalavryta river from the water's flowing to another stream, which joins the sea at two miles to the westward of the former and is called the river of Bokhusia. The Hellenic remains consists of several foundations and pieces of wall, of some of which there are two or three courses still extant. The city was on the Eastern face of the ridge. Looking towards the Kalavryta river. I conceive it to have been Ceryneia. Proceeding obliquely down the mountain, which forms the Eastern side of the ravine of the river Bokhusia. We arrive at 11:35 at a derveni or guard house. The sides of these mountains are beautifully variegated with pines and shrubs and clothed with a fine pasture. 11:55 arrive at the spot where the river emerges from the ravine into the maritime plain, which widens from hence to Vostitsa. Immediately afterwards, we cross the river and proceed along the plain. At 1:30 cross the river of Vostitsa, a rapid stream, difficult to pass after rains. At 2 arrive in the middle of the town of Vostitsa. The river is formed from several tributaries, of which the sources are near Aio Vlasi, and in the summits to the eastward of that place. The united stream flows from thence between the mountains of Voidhias and Klokos and enters the plain immediately behind Vostitsa, after which it makes a circuit to the right, so as to join the sea between two and three miles to the eastward of the town. This is from Leake Travels in the Morea volume three, which was published in 1830. Pages 182 through 185. I'm Jen Glaubius, and this is the Helonaki Deep Dive, a podcast about mapping and analysis for historical and archeological research. In this episode, I'll discuss the landscape of Vostitsa. Part of which was described by Leake during his second journey in the Morea in 1806 in the passage that I just read. I also want to let you know that I have created maps related to this episode, which you can view on the Helonaki website. The link to the page with the maps for this episode is in the show notes. Let's dive in. When I talk about the landscape I'm looking specifically within the borders of the 1700 Venetian territory of Vostitsa, now the 1463 places in the Ottoman defter go further south towards Kalavryta further into the higher mountains. But I don't have firm boundaries for that because they really didn't have boundaries between these places in 1463. And because 1700 is the middle time period that we're looking at. All of the information and analyses are going to be based on the 1700 Venetian borders. So within those borders, the entire territory of Vostitsa is within 22 kilometers or 14 miles of the coast. It's all hugging the coastline of the northern Peloponnesus. Leake's route through ravines to reach the coastal plain was typical for north south travel in the Vostitsa area. Except for the relatively flat plain along the coast, the Vostitsa landscape consists of a series of ravines and valleys running north to south. Here's how the Vostitsa landscape formed. The story starts tens of millions of years ago. When the shells of sea creatures accumulated deep underwater and through time were compressed together to form limestone. The limestone was lifted up to form mountains between 56 and 34 million years ago. As the area was compressed as tectonic plates came together. In the last 23 million years. The area is no longer being compressed, but now is being stretched apart. This extension of the landscape through stretching has fractured the brittle crust into blocks, separated by fault lines. Some of the blocks moved downwards, like the Gulf of Corinth to the north of Vostitsa, which is called a Graben. While others known as Horsts move upwards. And this is like the mountains of Arcadia to the south of Vostitsa. As the Arcadian mountains moved upwards, they eroded. And the sediment from the mountains was transported north by streams and deposited in the Vostitsa area as alluvial fans at the base of those mountains. Lowered sea level during the glacial periods in the Pleistocene caused the streams to cut into those alluvial fans, creating the present day, ravines and valleys. While the coastal plain was also formed by river deltas in the Gulf of Corinth that were lifted up above sea level. Today, the coastal plain in the Vostitsa area reaches at most 6.5 kilometers or four miles inland. But it's mostly much less than that. It extends along the coast, about 24 kilometers or 15 miles from the Western border towards the east. And there's a break where the cliffs are straight up against the Gulf of Corinth without a coastal plain. And then on the very Eastern most side of Vostitsa, there's five kilometers, about three miles of a coastal plain again. The coastal plain is an area where agriculture is fairly easy, but it's a very small part of the overall territory. Most of the area is foothills going up towards the mountains, that get highest towards the south. And this area as you might've been able to discern from what I read of Leake's description of this area. Really it's divided up by ravines that these streams go into and so travel in some ways is much easier going north south, the way that the streams are going from the mountains towards the coastline. There's a number of these streams. We're going to go from east, towards west, within the territory. Further east than Leake reached was the Krathis, which comes out about Akrata. It's on the east side of this territory. There was also not in the present day, but on the Venetian map from 1700, there was also a stream that was east of where Leake came out that entered the Corinthian Gulf at the present day Punto promontory. The next ravine, the stream is the Voraikos, which comes out about west of Diakopto. This is the ravine that today there's a rack railroad that goes from Diakopto to the Mega Spileo monastery and then on to the town of Kalavryta. That's basically the path for the first part of Leake's route going from Mega Spileo towards what today is Diakopto. So to the west of that is Rema Kerinitis, which enters the Corinthian Gulf east of Nikoleika. And this is the stream that Leake called Bokhusia. So the second one that he was following to go towards the coast. And then he came out on the coastline. And eventually he reaches, the Selinous Potamos which is the Selinous river. Which during Leake's time flowed closer to Aigio. So it was within two to three miles and now it's further east due to an earthquake. The Selinous is what Leake called the river of Vostitsa, because it flows the closest to the town of Aigio which was called Vostitsa. So further west than was in this passage by Leake there's the Rema Meganitas, which enters the Corinthian Gulf northwest of Aigio. Many of these streams, especially on the Eastern side, have very sharp ravines, especially away from the coast. And it's easiest to travel as Leake did traveling down these different ravines or stream valleys. Elevation is the basic data I'm using to study the landscape of the Vostitsa area. The elevation data is in a digital elevation model, also known as a DEM. This DEM I'm using has a 25 meter resolution. Which means that sudden changes in elevation that occur in less than 50 to 100 meters, like things like cliffs, those can not be detected. But the 25 meter resolution is still good for larger landscape features, which is why I'm using it. Within the Vostitsa study area, the elevation goes from zero meters above sea level, along the coast to 1,748 meters above sea level to the south, which is a change in elevation of over one mile. Now elevation is the first step of looking at the landscape because I also use the DEM to compute other landscape measures such as slope, ruggedness, and classifying landforms. Slope is the change in elevation over a distance. You might've learned it in school as rise over run. So through the magic of GIS, I transformed the DEM into a slope map, and you can see this slope map, and other maps on the Helonaki website using the link. So, if you look at that slope map, you can see that the slope is very close to being flat on the coastal plain. Although there are a few other smaller upland plains further to the south. The steepest slopes are in the ravines on the eastern side of the territory. And then also there's some steep slopes, not in ravines on the southwestern border, where it's going up to the mountains. If we think ahead a little bit about how humans use a landscape, which we'll get into in the next episode. If you think about it flat or gentle slopes are the easiest to use. But in areas such as Vostitsa, and across much of Greece, steeper slopes have been cultivated for thousands of years. Often by building terraces, walls that divide up a slope to create small flat areas. Some of the villages in the more mountainous parts of Vostitsa use terraces to create enough space for houses. Because the terrain is otherwise just too steep for even a small sized house. All right. So leaving slope behind another measure of landscape that I'm using is ruggedness. Which measures how much the terrain goes up and down over a certain distance. An area can have a steep slope, but not be very rugged, if the slope only goes one direction. Versus if the terrain goes up and down a lot then it's going to be more rugged, even if there isn't much slope change. Most of the Vostitsa area has fairly low ruggedness because it's hilly, it's the foothills towards the mountains, but it's not in the mountains themselves. The lowest ruggedness of course is along the coastal plain. While the most rugged part of Vostitsa is the southwestern border area, which is approaching the mountains further to the south. The last measure I want to talk about with respect to Vostitsa landscape is landform. Landforms can be classified in many ways, but I used a topographic position index method that's available in QGIS using the SAGA toolbox. That classification yielded 10 landforms, which I simplified to five, which are stream/drainage, valleys, plains, slope, and ridge. And slope in this case just means that the landscape is not flat so like the side of a hill, not the top, not the bottom. If you look at the landforms map using the link to the Helonaki website. As you might expect, the streams are bounded by valleys. So where you have a stream on either side, there are valleys and then slopes. Most of the area of the Vostitsa territory is classified as slopes While the next largest classification is plains. Including elevation, those are four different ways of looking at the landscape and looking at them all together, you get the idea that the coastal plain is one very easy area to use. The ravines, especially on the Eastern side of the territory are steep and would not have been easy to travel through or to live in. And then another area that would be very difficult to do anything in is that Southwestern part of the territory that's approaching the mountains. Now one analysis I have not done for the Vostitsa area is classification of land cover. Which looks at what type of vegetation or surfaces cover a landscape. From my own observations from my travels in the Vostitsa area, I know that the more rugged areas and in the ravines are forested with pine trees. While more gentle slopes are cultivated with olive trees or vineyards. Very little of the area is cultivated with grains in the present day. But in the past grain would have been cultivated underneath olive trees and much more widely, when people were growing grain for their own consumption. So those are some of the basics about the landscape. Let's talk about a few processes that can affect the landscape itself. I was making my first trip to the Vostitsa area in 2004 exploring the landscape. I was driving around and I stopped for lunch near this place called Tsivlos at a small taverna. The person working had some English and I had a little bit of Greek and we were able to communicate enough and we ended up talking. I told him a little bit about what I was doing. And he told me the story of a giant landslide that he said happened during his grandparents' time that had reshaped the landscape. Just to make sure I have all the details, I did some additional research since I didn't remember all the story. So here's what I know. On Sunday, March 24th, 1913. There was a large landslide of rocks and soil that came down from the Gerakari mountain. All that rock and soil slid down and it blocked the Krathis river. The village of Sylivaina came down as part of that landslide. While the village of Tsivlos where it was then was flooded by the new lake that was formed by the now blocked Krathis river. Unfortunately four people were killed during this incident, which destroyed both villages, but fortunately, most people in Sylivaina and Tsivlos had left the area due to smaller landslides two days earlier. So most people left the area and were safe. But it ends up that some of the houses and the semi submerged church of Agios Athanasios from the old village of Tsivlos are still visible in the lake. This happened just to the south of the Vostitsa area. So not within the area of analysis, but, there definitely were landslides, small and large through time. Especially in this type of mountainous, very sloping landscape. In addition to landslides, we also need to talk about earthquakes as a process that can really change the landscape. There was a fairly well-studied earthquake in 337 BC, that destroyed the city of Helike, which was attested in ancient authors. And there's an archeological project that's been working In that part of Vostitsa looking for Helike, which they think they've done. They've done studies of soils and sedimentology and other things like that to look at what happened. As for modern times, the latest big earthquake in the area was on June 15th, 1995. When there was a 6.5 near Aigio that affected the town. Most of that damage has been taken care of. But if you ever visit Aigio, there are signs around talking about the earthquake damage. I was also able to find some information about earthquakes from Before there was monitoring in the area. I got these from a paper that I'll link to in the show notes. This paper looked at information about earthquake damage from reports, correspondence, newspaper articles and things like that. To get an idea of where the epicenter probably was, the magnitude, things like that. So let's talk about a few historic earthquakes. First, there was one on May 14th, 1748. Fortunately, there were some foreshocks before the main earthquake actually happened that warned the inhabitants. So they were actually outdoors and not inside. There were very few casualties, but otherwise this earthquake caused a lot of damage. There were houses, churches, towers, all fell down. And along with the earthquake, it also caused a tsunami that had three waves, that hit Aigio. Each one was higher than the last. And the third wave was higher than the large plane tree, which is right at the harbor. It's a very large tree. I put a picture, on the page with the maps. So you can see, at least what the tree would have looked like back in the 1700s. There was another large earthquake on August 23rd, 1817. Most of the town of Vostitsa, which is modern Aigio was destroyed. Most of the houses were damaged. There was damage to the churches. This was at the very end of the Ottoman period, so there was a mosque which was completely destroyed by this earthquake. There were similar damage in nearby villages of Cumari, Zevgolatio, Temeni, Mourla, and Dimitropoulo. This earthquake, like the one in 1748 also caused a tsunami. This tsunami hit both sides of the Gulf of Corinth. So not just the Vostitsa area, but across the Gulf of Corinth. Because of the tsunami at Vostitsa itself, 18 people drowned in the tsunami. Sea level rose almost seven meters and it flooded a few different areas. It was because of this earthquake that the Selinous river, which is close to Aigio, shifted course slightly to come to the Gulf of Corinth further east than it had before. So the mouth of the Selinous river is further away from Vostitsa from the town of Aigio than it used to be. Another massive earthquake occurred on December 26th, 1861. The worst damage was not in the town of Vostitsa or Aigio itself, but just east of it. And in some of those villages, all of the houses, schools, churches, and other buildings collapsed. In Aigio there was less damage, but still many buildings collapsed or cracked or were inclined sideways. There was a little tsunami, which flooded the harbor road and the springs that are near the plane tree. But there was also, flooding of the coast between the Selinous and Vouraikos rivers and also between Diakopto and Pounta which is a little peninsula out into the Gulf of Corinth. So in those areas, there were cracks and liquefaction. There were at least seven deaths of people because of the 1861 earthquake, 126 people were injured. And in the districts Aigio and Boura within the Vostitsa area, at least 2000 families lost their homes in this earthquake. On August 29th, 1888. There was another big earthquake. This one happened with two to three big shocks. So not just one main shaking event. And there were also strong aftershocks. One person died over 20 were injured. There was a lot of damage in Aigio. Of 1,300 houses in Aigio at that time, 1000 of them were damaged. So only 300 houses, escaped damage. Waterflow to Aigio was interrupted. And then it came back, but it came and went for about 24 hours. And there was large amounts of damage in the nearby villages of Kouloura, Valimitika,Temeni, and Mourla So from these historic events, we can tell that earthquakes have changed the landscape. They changed the course of rivers. They bring on tsunamis that deposit. And they of course caused a lot of damage to buildings. So this is something that the people of Vostitsa have been dealing with. The landscape described by Leake during his travels in 1806, has been inhabited and used by humans for thousands of years. You almost wouldn't know it from Leake's words, since he describes the vegetation of pine and shrubs and pasture. He touched on the remains of ancient Keryneia. But he described Keryneia much more than any fountain or any village that he passed on that section of his trip, from Mega Spileo to the town of Vostitsa. So you can tell that his interest was in ancient sites and in the landscape. But not necessarily on the peoples of the area. The coastal plain would have been cultivated and dotted with villages, but Leake did not describe any of that in this section. What he does talk about are the streams that he crossed and where those streams originated. So Leake's account leaves me with questions. Did he not come across any villages on the coastal plain. I understand not having villages in the ravines, but there's so many villages on the coastal plain today. Did he not pass any of them? On his route to the town of Vostitsa, which is Aigio. So has human use of the landscape changed since Leake traveled to Vostitsa in the early 1800s. I'm also interested in how human use of the landscape has changed since 1468, the earliest of our time period. So we're going to start exploring that by looking at settled locations on the landscape in the next episode. And now for some endnotes. The ravines through which Leake traveled are mostly untouched by humans even today. There is a rack railroad that travels from the town of Diakopto near the coast up through the ravine to the monastery of Mega Spileo. Which is where Leake began, his entry that I read. And then the railroad continues on to the town of Kalavryta. It's a beautiful journey, which I highly recommend, if you ever travel to that part of Greece. The information about historic earthquakes came from a 2017 article by Albini and others titled "Large 18th- 19th century earthquakes in Western Gulf of Corinth with reappraised size and location". I thought the article was a really cool use of archival research into correspondence, official reports and newspaper articles, and then using that information to study the magnitude and impacts of earthquakes in areas without other data. And I will be using some information from this article again in a few episodes. The information about the Tsivlos landslide is on the Greek version of the Wikipedia page for Tsivlos. It's not on the English version. But if you have Chrome, it can translate from the Greek to English automatically. A link to that Wikipedia article is also in the show notes. Thanks for listening. Email questions or comments to deepdive@helonaki.com or ask them on the Helonaki Deep Dive Facebook page. Show notes with links to resources mentioned in this episode will be available at helonaki.com. That's H E L O N A K i.com. You can also find ways to support the show now, including merch, such as t-shirts, mugs, and stickers with the Helonaki Deep Dive logo at helonaki.com/support. My thanks to Patreon supporters at the geospatial analyst level, Leah Varrell and Janice and Jerry Farrell. Your support keeps the Helonaki deep dive going. The Helonaki Deep Dive is written and produced by me, Jen Glaubius of the Helonaki. The theme music is Deep Ocean, instrumental by Dan o of dan o songs.com, additional sounds from zap splat.com. Thanks for listening.