How to Integrate Invisible Geomorphosites in an Inventory: a Case Study in the Rhone River Valley (Switzerland)

Abstract

During the two last decades, numerous inventories of geosites have been carried out at various scales. They aim at documenting the state of the geological heritage, which is the basis for management strategies. In very humanized regions, where the original geomorphology has been highly modified by human infrastructures, agriculture, urban sprawling, and various modifications of landforms, it is important to inventory not only the landforms visible today but also former landforms destroyed or hidden by human activities. To address the issue of inventorying invisible geomorphosites, two approaches were tested in the Rhone River valley (Switzerland). The first was an inventory of geomorphosites of the study area. Not only the visible landforms but also the landforms that had completely disappeared were evaluated with the assessment method of the University of Lausanne. A total of 28 geomorphosites were assessed including five missing sites (two sand dunes areas, a braided sector of the Rhone River and two former marshes). These invisible geomorphosites were assessed and their management was discussed. The second study was a multi-method analysis of former landscapes of the 19 th century. Several data including historical maps, written archives, digital terrain model and iconographic sources were combined and allowed the reconstruction of palaeolandscapes and landforms. Both materials allowed proposing a strategy for geotourism development.

Existing and Proposed Urban Geosites Values Resulting from Geodiversity of Poznań City

“…Both existing and proposed geosites discussed in this article meet the criteria for visibility and invisibility proposed by Clivaz and Reynard (2017). Boulders, though visible today, are not in a landscape position in situ.…”

“…Hence, in urban areas, places which deserve to be called a geosite occur either in excavations or filled-in pits. Therefore, the delimitation of visible and invisible geosites by Clivaz and Reynard (2017) seems reasonable.…”

Urban Geomorphological Heritage. An Overview

“…The overlay of historical maps in a GIS environment enables comparison, spatial analysis and quantification of landscape changes due to urbanization. The digitization of territorial features allows the quantification of changes over time (appearance and disappearance of elements, Stäuble et al 2008, Baud and Reynard 2015, Clivaz and Reynard 2017. This approach was particularly used for the reconstruction of river landscape evolution in urban contexts; among the numerous studies are the works on the Danube River in Vienna (special issue of Water History, 2013, in particular Winiwarter et al 2013, Hohensinner et al 2013a, b, Haidvogel et al 2013, on the Garonne River in Toulouse, France (Valette, Carozza 2013) or on the Rhone River in Lyon, France (Bethemont, Bravard 2014).…”

“…geomorphosite assessment is, therefore, needed, which takes into account hidden, destroyed and invisible landforms (Clivaz, Reynard 2017) as well as man-made ones (anthropogenic landforms). However, many elements in the already known assessment methods are difficult to use: it is not easy to assess the scientific representativeness and the rarity of something no longer existing; so is it about the aesthetic value of an invisible site, or even the accessibility of places difficult to localize.…”

Photogrammetric Modelling for Urban Medieval Site Mapping. A Case Study from Curtea de Argeş, Romania

“…A lot of rock outcrops and a large spectrum of landforms of scientific interest are partially or totally covered by buildings and specific infrastructures like street networks (Serrano, Ruiz-Flaño 2009, De Wever et al 2016. There are only few exceptions, mostly from the regions with sharp morphological contrasts like the towns around fortresses on rock outliers (Clivaz, Reynard 2017). Several scientific papers focused on the importance of historical sites, most of them having a chronological significance in the context of urban development along centuries (Rodrigues et al 2011, Del Lama et al 2015, Erikstad et al 2017.…”