- \26.8.1817 Ötz/A - 6.3.1897 Umhausen/A\Adolf Trientl was a Jesuit and eventually became a wanderer who visited farmers in the Tyrol County as a clergyman and advised them in their daily lives. Besides he was an excellent observer of nature and contributed significantly to the understanding of debris flows and avalanches occurring frequently in the Ötztal, a part of the country.\Austria as a country in the pre-Alps suffered ineffably from natural disasters due to steep slopes and large debris accumulation. Together with France and Switzerland, it was the first country proposing means to counter these risks. Despite the general belief that deforestation had caused landslides and debris flows, Trientl stated that this may be correct only up to some 2,000 m elevation above sea level, the upper limit of forests. If debris was located up this elevation, the forest had no direct effect on debris flows or avalanches. Trientl as an excellent observer described these phenomena in detail and laid the basis for later scientific approaches, as initiated around 1900 by natural scientists such as Ferdinand Wang (1855-1917), Georg Strele (161-1950) or Josef Stiny (1880-1958). These descriptions included the generation zone, the debris transportation canals and the depositions area. He also proposed that forests need be conserved and that rivers be cleaned from trunks. He lashed robber-farming and the waste of wood. He also initiated the active protection against snow avalanches by retention basins and deflection walls, such that the snow would be unable to destroy villages. Based on his constant observations, Trientl appears to be far ahead in the knowledge of active protection means against these natural hazards; he correctly accounted for the passive protection of forests and that the location of settlements in steep valleys should be carefully considered.\Heumader, J. (1991). Adolf Trientl über Muren und Lawinen. Wildbachund Lawinenverbau55: 233-239. PHofinger, W. (1992). Adolf Trientl - Der Mistapostel: Ein Leben für den Bauernstand. Haymon: Innsbruck. PStrele, G. (1934). Grundriss der Wildbachverbauung. Springer: Wien. Trientl, A. (1870). Die Verbesserung der Alpenwirthschaft. Gerold: Wien.Trientl, A. (1884). Allgemeine Betrachtungen über die Bauernwirthschaft und Grundzüge der Düngung. Wagner: Innsbruck.Trientl A. (1892). Allgemeine Grundsätze des Feldund Futterbaues. Wagner: Innsbruck. Wang, F. (1901). Grundriss der Wildbachverbauung. Hirzel: Leipzig.
Hydraulicians in Europe 1800-2000 . 2013.