HR: 1340h
AN: GC13A-0948    [Abstracts]
TI: Integrated modelling and GIS: A new approach to assess desertification vulnerability and risk in Sardinia Island (Italy)
AU: * Santini, M
EM: monia.santini@unitus.it
AF: DiSAFRi Department, University of Tuscia, via S. Camillo de Lellis snc, Viterbo, 01100, Italy
AU: * Santini, M
EM: monia.santini@unitus.it
AF: Honors Center of Italian Universities (H2CU), University of Rome La Sapienza, via Eudossiana 18, Rome, 00184, Italy
AU: Caccamo, G
EM: g.caccamo@agriconsulting.it
AF: Agriconsulting spa, via Vitorchiano 123, Rome, 00189, Italy
AU: Noce, S
EM: s.noce@agriconsulting.it
AF: Agriconsulting spa, via Vitorchiano 123, Rome, 00189, Italy
AU: Valentini, R
EM: rik@unitus.it
AF: DiSAFRi Department, University of Tuscia, via S. Camillo de Lellis snc, Viterbo, 01100, Italy
AB: Land degradation assessment is a prior goal in decision support system for environmental protection, mainly in the Mediterranean area. Among various approaches, a model based methodology seems the most effective to monitor degradation processes and to plan mitigation actions, as it combines synergically many indicators categories of DPSIR (Driving Forces, Pressure, State, Impact, Response) framework. The presented approach is applied for desertification risk evaluation in Sardinia (Italy). Assuming desertification as the interaction among both predisposing (i.e. geographic location), triggering (i.e. extraordinary climatic events) and quickening (i.e. as human activities) factors, a new methodology was developed combining together, in the structure of an integrated model framework, a wide range of desertification indicators already developed by various projects focusing on Mediterranean area. A large multi-thematic dataset has been acquired consisting of about eighty geographic information layers. This data have been processed and re-arranged in a GIS environment in order to supply the input to several models regarding the typical degradation processes occurring in the Mediterranean area. In this study five processes were taken into account: soil erosion, soil biological degradation, loss of vegetation productivity, coastal aquifer salinization and overgrazing. The modelling procedure has been applied for two different periods according to the largest availability of data: the early nineties and the present. The outcomes from the model simulations were spatialized into separated vulnerability maps, one for each degradation process. Model results were normalized as indices varying from 0 (no degradation) to 1 (irreversible degradation); then, these degradation indices are integrated into a final one, with the same range of values, combining together different aspects of desertification, their magnitude and their development rate, giving different weights according to the importance of a single process and the quality of input data. This approach allows to highlight both spatial and temporal variability of desertification phenomenon, as well as to estimate land vulnerability as respects each single degradation process. The temporal variability is driven by both past trends and future simulations of land use and climate changes. The results have been then validated by applying the same methodology on a larger scale for an area resulting as hotspot of desertification from the first application on a smaller scale, in order to detect and verify the real situation. The risk is considered the final product between vulnerability and value of "at risk" elements. Moreover, from environmental vulnerability assessment and jointly with more strictly socio-economic aspects of land use change directions and scenarios, it will be possible to detect areas at different risk for the future, again in a GIS-oriented approach, supplying an useful tool in predisposing prevention, adaptation or mitigation countermeasures to desertification.
DE: 0466 Modeling
DE: 0468 Natural hazards
DE: 1632 Land cover change
DE: 1809 Desertification
SC: Global Environmental Change [GC]
MN: 2007 Fall Meeting