**3. The study area: The Subasio Mountain regional park (Umbria, central Italy)**

The study area is located in the Umbria region (central Italy). This region is well-known because of its natural heritage and exceptional geological value. Twenty-seven geosites or "*any place where you can define a geological and geomorphological interest for conservation*", (Gray, 2004) are already individuated and studied. Seven regional and one national natural park are present on the territory (Figure 1).

The entire region shows a strong correlation between geological attributes and the relief energy associated with topography assessment.

The Subasio Mountain regional park covers an area of 7,200 hectares. The area has a triangular shape, is bordered to the south by the Subasio massif, a rolled and asymmetric anticline. To the west the limit follows the Tescio River. Towards NE the central part and the apex are crossed by close river networks.

In the study area outcropping lithotypes can be clustered in three main complexes and in different types of superficial deposits (Figure 2).

The first and youngest is the Fluvial **L**acustrine Complex (Holocene – Pliocene) with pebbles, sand and clay sediments arranged in deposits that are heterogeneous for thickness, shape and areal extent. This complex is associated with the lowest slope values and plain areas.

The second complex is the Terrigenous one (Miocene), consisting of alternating layers of sandstone or limestone with clay or marl. According to the percentage of clay and the dip

2. Ground survey methods with a set of field data (points) collected with Global Position System (GPS) or Electronic Distance Measuring (EDM). Although this method allows to save a large number of input data in areas with a strong topographic complexity, it is time consuming and sometimes very expensive. Therefore, it can be a reasonable choice

3. Remote sensing techniques with passive and active sensors. These procedures permit to obtain data with a very high horizontal resolution and vertical accuracy for large areas. Nowadays remote sensing DEMs are the improving resource in this field research and

When, by transparency tools, satellite images or digital orthophotos (geological, geomorphological, land-cover e.g.) are overlaid as several thematic maps to a shaded relief, a composite visualization is achieved. In geomorphology DEMs are commonly used to calculate topographic attributes (Franklin, 1991; Moore et al., 1991; Pike, 1988; Wiebel & Heller, 1991). Among them, primary attributes are morphometric parameters deriving from DEMs, i.e. slope, aspect, plan and profile curvature. The visualization of topographic attributes and their analysis can be a very useful tool to better understand the

Remotely sensed imageries have a large improvement in both areal coverage and technical characteristics. Moreover, the selection of the most fitting band combination in RGB (Red, Green, and Blue) allows highlighting the required morphological characteristics and

**3. The study area: The Subasio Mountain regional park (Umbria, central Italy)**  The study area is located in the Umbria region (central Italy). This region is well-known because of its natural heritage and exceptional geological value. Twenty-seven geosites or "*any place where you can define a geological and geomorphological interest for conservation*", (Gray, 2004) are already individuated and studied. Seven regional and one national natural park

The entire region shows a strong correlation between geological attributes and the relief

The Subasio Mountain regional park covers an area of 7,200 hectares. The area has a triangular shape, is bordered to the south by the Subasio massif, a rolled and asymmetric anticline. To the west the limit follows the Tescio River. Towards NE the central part and the

In the study area outcropping lithotypes can be clustered in three main complexes and in

The first and youngest is the Fluvial **L**acustrine Complex (Holocene – Pliocene) with pebbles, sand and clay sediments arranged in deposits that are heterogeneous for thickness, shape and areal extent. This complex is associated with the lowest slope values and plain

The second complex is the Terrigenous one (Miocene), consisting of alternating layers of sandstone or limestone with clay or marl. According to the percentage of clay and the dip

only for some restricted areas.

geomorphological processes acting on a study area.

processes and facilitates landforms recognition.

energy associated with topography assessment.

different types of superficial deposits (Figure 2).

are present on the territory (Figure 1).

apex are crossed by close river networks.

areas.

application.

Fig. 1. Location map of the Umbria Region (central Italy). The white circle marks the Subasio Regional Park. (1) Geosites, (2) Regional Parks.

Fig. 2. Left: DEM of Subasio Mountain Regional Park with altitude values in meters a.s.l. Right: geological map. (1) Alluvial deposits, (2) Colluvial deposits; (3) Debris deposits (active); (4) Debris deposits (ancient); (5) Fluvial **L**acustrine complex; (6) Travertine; (7) Calcareous complex; (8) Terrigenous complex with prevalent clay percentage; (9) Terrigenous complex with prevalent arenaceous percentage.

The Use of Remote Sensed Data and GIS to Produce

Mayer et al., 2003).

**approach in a GIS environment** 

map starting from the analogical data.

summarized in Figure 5.

a Digital Geomorphological Map of a Test Area in Central Italy 103

The geologic history of the area is tightly related with geological evolution of central Italy. From a tectonic point of view the area is the result of two different tectonic periods. In the Miocene a compressive phase originated anticlines and synclines (like the Subasio Mountain) followed, since Pliocene, by uplift with an extensional tectonic phase affecting the entire area. Because of this, a sharp increase of energy relief has forced the entrenchment of the stream network resulting in headward and stream erosion and with the simultaneous triggering of landslides along the slopes (Malinverno & Ryan, 1986,

The strong heterogeneity of the substrate is responsible for the great variety of relief and geomorphological processes acting on the area. Hence, the Subasio M. Park is a perfect test-

The essential steps required to elaborate the final digital geomorphological map are

Fig. 5. Flow chart showing the steps required to produce the final digital geomorphological

The geomorphological map was produced to a medium scale 1:25000, with ESRI's ArcGIS 9.3 (© ESRI) with an equivalent project scale. The Spatial Reference is ED50 (European Datum) UTM (Universal Transverse Mercator) Zone 33N. The project extent is set on the

**4. The interactive geomorphologic map: A qualitative and quantitative** 

area to assess a method focusing the geomorphologic map editing.

direction of the layers, the energy relief shows medium values. Mass wasting processes prevail together with fluvial erosion landforms on a rolling hill landscape (Figure 3).

The oldest complex is the Calcareous one (upper Trias – Oligocene) corresponding to the mountain areas of the region and to the highest values of energy relief and altitude. The Calcareous Complex consists of a thick multilayer sequence where limestone prevails and karstic features and debris deposition at the base of the slopes are the most frequent geomorphological morphotypes (Figure 4).

Fig. 3. The Terrigenous Complex view, photographed from the top of Subasio Mountain, northwards (photo by L. Mancinelli).

Fig. 4. The Calcareous Complex on the top of the Subasio Mountain with a macro-doline in the foreground (photo by L. Mancinelli).

direction of the layers, the energy relief shows medium values. Mass wasting processes

The oldest complex is the Calcareous one (upper Trias – Oligocene) corresponding to the mountain areas of the region and to the highest values of energy relief and altitude. The Calcareous Complex consists of a thick multilayer sequence where limestone prevails and karstic features and debris deposition at the base of the slopes are the most frequent

Fig. 3. The Terrigenous Complex view, photographed from the top of Subasio Mountain,

Fig. 4. The Calcareous Complex on the top of the Subasio Mountain with a macro-doline in

prevail together with fluvial erosion landforms on a rolling hill landscape (Figure 3).

geomorphological morphotypes (Figure 4).

northwards (photo by L. Mancinelli).

the foreground (photo by L. Mancinelli).

The geologic history of the area is tightly related with geological evolution of central Italy. From a tectonic point of view the area is the result of two different tectonic periods. In the Miocene a compressive phase originated anticlines and synclines (like the Subasio Mountain) followed, since Pliocene, by uplift with an extensional tectonic phase affecting the entire area. Because of this, a sharp increase of energy relief has forced the entrenchment of the stream network resulting in headward and stream erosion and with the simultaneous triggering of landslides along the slopes (Malinverno & Ryan, 1986, Mayer et al., 2003).

The strong heterogeneity of the substrate is responsible for the great variety of relief and geomorphological processes acting on the area. Hence, the Subasio M. Park is a perfect testarea to assess a method focusing the geomorphologic map editing.
