CH4 is a greenhouse gas which is consumed in aerobic soils and
produced in anaerobic environments such as wetlands and rice
paddies. Due to its climatic and geomorphologic characteristics, most
of the Italian peninsula is characterized by aerobic soils and hence
can be considered a sink of atmospheric CH4. A quantification of such
sink at national scale has not been done yet. As available data of CH4
fluxes for Europe mainly refer to its Central-Northern area, a
quantification of the Italian CH4 sink cannot be done by scaling up
site fluxes to landscape level.

In the present study this CH4 sink was modellized in a GIS environment
IDRISI. The GIS program was implemented with specific modules written
in the "Python" language, used for the modellization of the different
ecological processes involved: a module of soil water content; a
module to estimate the normalized diffusivity (ND) of CH4 in
aggregated media; a module for the modellization of CH4 fluxes based
on ND and biological response of methanotrophs to temperature; a
module for CH4 fluxes in highly drained sandy soils describing an
empirical algorithm mainly based on soil porosity. All the input
variables and the output values were georeferred (UTM 32 N) and
presented in raster format. Input data included metereological data
(MARS), soil characteristics (JRC), land cover (CORIN2000), derived
variables calculated on available soil properties and known soil
characteristic associated to such properties from literature data.