## 1 Introduction  
Traditional geomorphological mapping (TGM) is a significant tool for landscape representation, mostly used for territorial planning. Moreover, it allows for the specification of the morphological response to lithological variability and geological structure. Though the importance of geomorphological mapping is generally recognized, this traditional tool can't overcome limits such as the impossibility of completely representing landforms and their relationships due to the use of linear symbols for mapping areal landforms. In addition, traditional geomorphology, using only dimensionless symbols, is unable to specify the actual size of landforms. A geomorphological map can be considered a graphical inventory of a landscape depicting landforms and outcropping rocks. TGM mays either focus on selected landscape features, for example, only depicting the morphology of active processes, or deliver a full view on the landscape composition and its evolution [1, 2]. Sketches and maps of landscapes and landforms have been fundamental methods to analyze and visualize the Earth's surface features since early geomorphological research. The widespread distribution and extended graphical capabilities of geographic information system (GIS) as well as the availability of high-resolution remote sensing data such as aerial and satellite imagery and digital elevation models (DEMs), or recently, by the UAV method (unmanned aerial vehicle), has led to the recent rejuvenation of the TGM method [3]. In detail, GIS is the most-used tool for drawing geomorphological maps, composed of areas, lines, and points represented through symbolization rules. Through GIS, the attributes of elementary geometric entities are used for their cartographic representation [4]. This research reports a new tool for geomorphological mapping in the GIS environment, using a full-coverage object-based method (OBM). The aim of this work is to evaluate the advantages and disadvantages of this new method and to compare it with the traditional one. Geomorphological mapping methodology is built with simple element (\"object\") dataset related with various kinds of class relationships (geometric, temporal, physical, geological, lithological and hierarchical) and procedures for their interpretation [4]. The polygon is the simplest geometric element that allows for a physically-based representation of a landform. By combining adjacent polygons, the whole physical surface can be represented. The decomposition and composition of the polygons, depending on the representation scale, are obtained deriving objects such as lines and points that are themselves elements of geomorphological maps with symbolic representation. The new geomorphological legend proposed by the ISPRA-AIGEO-CNG working group for geomorphological mapping distinguishes objects on the basis of the morphogenetic agent and the state of activity. All this information must be present on the table of attributes of the shape files, with the aim of giving the possibility of generating several thematic map. The creation of a field mapping protocol that details the steps of the mapping campaign is important, as it allows the organized collection of additional information on landforms and the creation of a database for the data mapped in the field. The mapping scale used for data recording is usually larger than the scale of the final map, in order to collect as many details in the field as possible. Consequently, map production requires a generalization of the field data. It is worth noting that medium and small-scale geomorphological maps exist, ranging from 1:100,000 to >1:1,000,000 [5, 6]. We apply this new methodology in the Western Alps, following the guidelines of the new geomorphological legend proposed by the ISPRA-AIGEO-CNG working group for geomorphological mapping. The use of full-coverage OBM is applied to an area extensively affected by deep-seated gravitational slope deformation (DSGSD) in the Western Alps (Rodoretto Valley).