The area of Zero Branco has been studied comparing the current regional technical map with the map of the Geographic Military Institute (1940) and the ones of the Napoleonic (1810) and Austrian (1842) land registers as well as the descriptions gathered by Anthon von Zach (1798-1805) to highlight changes.
As regards history the area has not changed from the topographic point of view, whereas as far as landscape is concerned a gradual loss of wooded land to take advantage of agriculture can be seen. The only real changes over 150 years are the highway nr. 155, highlighted in the Austrian cadastre, and the bypass of the city center, shown in the map of the Geographic Military Institute. The other great changes which can be seen in the regional technical map happened later.
In all the maps the river has a more meandering flow compared with today’s one. its bights would be regulated after 1940.