A Quantitative GIS and AHP Based Analysis for Geodiversity Assessment and Mapping

Andrea Ferrando,Paola Coratza,Guido Paliaga,Francesco Faccini

doi:10.3390/su131810376

Abstract

In recent times, the issues of geodiversity assessment and mapping have been subject of great attention, and many evaluation methodologies, either quantitative or qualitative, have been developed. In this research, a first assessment of geodiversity in the Liguria region has been carried out, according to a quantitative method based on spatial analysis techniques implemented in a GIS environment. This method considers four diversity indices obtained by grid analysis, relevant to the four main aspects of geodiversity: geology, geomorphology, hydrogeology and pedology. The geodiversity index was calculated two times, first with a non-weighted sum, then with a weighted sum of the four diversity indices. In the second case, the weights have been assigned according to a semi-quantitative analytical hierarchy process method (AHP) based on experts’ judgment. The results show that the Liguria region is characterized by many areas with high geodiversity, most of them internationally known by geoscientists and tourists for their valuable geoheritage and for their stunning landscapes. The correspondence between these areas and the protected areas of the european Natura 2000 network suggests a link between geodiversity and biodiversity.

Highlights

The word “geodiversity” was coined in the 1990s (e.g., [1,2]) and has been rapidly accepted by geoscientists, even if this term has frequently been used rather loosely
Over the last few years, numerous geodiversity assessment methods have been proposed, which can be grouped into various sets depending on the data source and the procedure
The analytic hierarchy process (AHP) weighted geodiversity map allows to mitigate the limitation of using the available low resolution pedological factor data by reducing the soil–landscape unit weight

Summary

Introduction

The word “geodiversity” was coined in the 1990s (e.g., [1,2]) and has been rapidly accepted by geoscientists, even if this term has frequently been used rather loosely. There are several definitions to geodiversity (e.g., [2,3,4,5,6,7,8,9]), but the most widely used is “the natural range (diversity) of geological (rocks, minerals, fossils), geomorphological (landforms, processes) and soil features. It includes their assemblages, relationships, properties, interpretation and systems” [10]. Indirect methods are based on calculations on numerical cartography, generally within a GIS environment; they are by far the most common, because the data acquisition is easier and considerably less expensive

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Discussion

Conclusion