Isar-Inn hill country
The Isar-Inn hill country is a natural spatial main unit that extends over a large part of Lower Bavaria and a small part of Upper Bavaria .
location
The Isar-Inn hill country is part of the Lower Bavarian Tertiary hill country . It extends from the lower Isar valley to the lower Inn valley. The area is about 3,650 km². It is mostly clearly separated from the rivers Isar and Inn and to the lower Rott by striking steps. There are only smooth transitions to the Neuburg Forest and the area around Osterhofen . In the northwest it continues as the Danube-Isar hill country and in the Austrian Innviertel as the Inn-Hausruckviertler mountain and hill country.
Emergence
Geographically, the hill country is already part of the Bavarian Alpine foothills . While the Alps formed in the Tertiary , deposits ( molasses ) collected to the south and north of them . The area only got its hilly shape during the Pliocene .
During the Tertiary, shallow inlets repeatedly pushed into the area via the Burgundian Porte and the Vienna Basin, depositing sand and marl here. The sediments of the Upper Freshwater Molasse , which were deposited 18 to 10 million years ago, form the undulating surface of the hill country. In addition to marl, there is also Nagelfluh , from which the mountain ranges often consist.
The area remained ice-free during the ice ages . Glacier downdrafts blew the fine particles out of the gravel and deposited them on the higher parts of the tertiary hill country, which is where the fertile loess comes from, the basis of today's agriculture .
relief
The surface shape is essentially the result of fluvial erosion . Only the areas on both sides of the Rott with their quartz conglomerate form a hard layer in the otherwise predominant loose rock . The highest peaks are in Schellenberg near Simbach am Inn (550 m) and in Steinkart near Bad Griesbach im Rottal (525 m). The deepest parts of the landscape are the lower reaches of the rivers Vils and Rott with about 320 m. The constant ups and downs of gently rolling hills and hollows are characteristic of the hill country. The hilly terrain increases from west to east and on the edges of the hill country, with a larger relief jump towards the Inn valley than towards the Isar valley.
climate
With a fundamentally sub-Atlantic climate , the Isar-Inn hill country is one of the most continental areas in Germany. The northern edge is relatively low in precipitation with up to 750 mm annual precipitation, while in the southeast in the area around Tann around 1000 mm can be measured. The reason for this increase in the south is the Alpine traffic jam and the higher elevation.
Floors
The loamy-sandy brown earth dominates with diverse transitions to other soil types such as pseudogley and podsol . The starting material for soil formation is usually not the tertiary material, but the loess or clay cover that occurs frequently .
Waters
Vils and Rott cross the Isar-Inn hill country. They also have their origin here and drain from southwest to northeast or east. The Vils is dammed in the Vilstalsee , the Rott in the Rottauensee . About 15 km before the mouth, the Vils receives the Kollbach in a wide basin as its largest inflow over the Vilskanal . Also gefällreiche streams are found on the edge hemming the Isar-Inn-hills in deeply carved ravines .
Settlement history
The Bavarian conquest of the 7th and 8th centuries is of decisive importance for the development of the cultural landscape in the area. As early as the end of the early Middle Ages, today's settlement pattern was largely pronounced. After the turn of the millennium, numerous aristocratic residences were built. Around 1100 the main area of settlement was reached.
It was not until the late 19th and 20th centuries, with industrialization and new agricultural management techniques, that significant changes were made to the cultural landscape.
Landscape image
Up to the present, around 70% of the Isar-Inn hill country has been characterized by small-scale, intensive agricultural use. The fodder farms predominate among the farms.
The proportion of forest area is around 25% and is thus well below the Bavarian average of around 34%. Especially in agriculturally favorable locations such as in the Vils and Rottal valleys, the proportion of forests is sometimes only 10%. The highest forest proportions are reached on the southern edge with around 30%. The spruce dominates the existing forest stands. Especially on the Inn- and Isarleite there are still isolated red beech forests (e.g. on the Dachlwand), on Rott and Vils there are also remnants of oak forests.
Larger places are Pfarrkirchen , Eggenfelden , Vilsbiburg , Bad Griesbach im Rottal and Ortenburg . The spa triangle is of particular tourist importance .
literature
- Ulrich Pietrusky, Günther Michler, Donatus Moosauer: Niederbayern - rediscovered in flight , Morsak Grafenau publishing house, 2nd edition 1982, ISBN 3-87553-135-3
- Christoph Stein: The moss, fern and flowering plant flora of the Isar-Inn hill country (southeast Bavaria) , in: Hoppea. Memoranda of the Regensburg Botanical Society , Vol. 60, Regensburg 1999