I happened to came across the catholic priest and Hungarian Academy member Tivadar Ortvay's (Theodor Orthmayer) decription on the islands of the Danube. This article was published in the 15 th volume of the "Mathematikai és Természettudományi Közlemények" (Bulletin for Mathematics and Natural Sciences) in 1878. The relation of the shape, direction, area and the height of the banks of the Hungarian Danubian islands was written in the style of the mid 19th century geographical view, with a lot of statistic descriptions. This article became obsolete almost in the moment it was published! It had been written before the large regulation works started on the Danube naming almost all (!) of the Danubian islands. This time islands still moved, changed their shape, direction, area and the height of their banks. Despite all, this work gives us a priceless snapshot on the state of the Danubian islands in 1878.
In this post we only discuss the most interesting part: the aspects of the islands area.
With diligent work, Tivadar Ortvay organized 667 Danubian Islands according their area in a spreadsheet without any help from GIS programs. He aslo recognizes this number is far from complete. According his calculations there will be 200 more islands not included in the Hungarian cadastrial register. In 1878, the year his work was published, the length of the Hungarian Danube was over a thousand kilometers, lasting from Dévény (Devín, Slovakia) to Orsova (today Romania). Due to river regulation works by 1893 this value was reduced to 997 km. Today it is only 417 km (Between 1941-1944, when Hungary took back Vojvodina it was 637 km).
Each island, represented in the cadastrial register, had their own unique names, but in some cases the name was not followed by the word "sziget" =island, rather "zátony" =river bar. Altogether their area was 296183.4663 hectare. We should add the area of those islands not included in the cadastrial register, but in this case we can only estimate the value. According to Ortvay's calculations it is approximately 316503 hectare, 3165 square kilometer. We are talking about a huge area. Even the cadastrial islands' area is larger than the state of Luxembourg. The cumulated area of the islands was larger than 17 counties of the Kingdom of Hungary. Altogether they made up 1.17 percent of Hungary's territory, 0,98 percent with Croatia.
Out of the 667 islands, the smallest one was called the Wirding shallow, in Moson county, western Hungary with 719 square meters, whilst the largest one made up alone 64% (188519 hectare) of the total islands area. This is the Slovakian Žitný ostrov, Csallóköz in Hungarian, largest inland island in Europe. The most common area fell between the 1-5 acre interval.
In 1878 these were the largest Danubian islands in Hungary:
- Žitný ostrov - Csallóköz 188519 hectare, 1885 square kilometer (1.b Szigetköz 37500 hectare, In Ortvay's article Szigetköz is not mentioned separately from Žitný ostrov)
- Csepel island, South from Budapest 25711 hectare
- Margita island (Mohácsi island) Hungarian-Croatian-Serbian border17793 hectare
- Szentendrei island, North from Budapest. 6138 hectare
- Острово (Ostrova island, Temes-sziget) Temes county, today Serbia 3918 hectare
- Décsi island (Tolna county) 3280 hectare
- Pacaris island (Bács-Bodrog county, today Serbia, east of Novi Sad) 2076 hectare
- Kalandos island (Baranya county, today Croatia) 1508 hectare
- Nagy Popovicza island (Baranya county, today Croatia, near Apatin) 1397 hectare
- Béda (Baranya county, near Kölked) 1371 hectare
|The Žitný ostrov and Szigetköz on Marsigli's map (1699)|
|Csepel Island (S. Mikoviny 1737.)|
|Mohácsi Island (googleearth)|
|Szentendrei Island (Marsigli 1699)|
|Temes-sziget (Ostrova Island- Serbia-Vojvodina - Béla Vályi)|
|Decsi Island (Hungary - 2nd military survey)|
|Pacaris Island (Serbia - Vojvodina - Béla Vályi)|
|Kalandos Island (Croatian-Serbian border - 2nd military survey)|
|Nagy-Popovicza Island (Croatia - Béla Vályi)|
|Béda (2nd military survey)|
The first five islands still exist with only a very little change in their area and form. The 6-10th islands are different. They changed their shape, size each and every year when a flood washed over them. New river branches were cut in them, new shallows emerged from the riverbed slowly merging with the island. Icy floods even devastated all the riverine forest from their surface. But changes in the nature did not affect the administrative borders. The Kalandos island's old Danube arm still shows as the border between Croatia and Serbia, even the Danube is miles away now.
Out of these ten islands only five exist today. The others had been eliminated by river regulation works, their side branches became oxbows, later disappeared in the last one and a half century. The largest islands in Hungary today are: the Szigetköz, Csepel island, Mohácsi island and the Szentendrei island. If we take the term "island" strictly there is only one island remaining: the Szentendrei island, others has been connected to the mainland by locks and with other river regulation facilities. That is why it would be hard to make a list from the ten largest island in present Hungary. Shall we consider a natural formation island if it is not completely surrounded by water and we only call them island by tradition?