Environmental Engineering Reference
In-Depth Information
Mediterranean North and South EnZs. The areas less favorable for agriculture
(Agri-mask classes one and two) are mainly located in the Alpine, Boreal and
Mediterranean Mountain EnZs. These EnZs show much lower relative shares of land
classified as land with no or relatively small constraints to agriculture (Agri-mask class
zero) than the overall EU27+ figure of 75.8%. Furthermore, lower organic carbon
contents are overrepresented in the Agri-mask class zero while the higher organic
carbon contents (classes five and six) are underrepresented in this class (see Hazeu
et al.
2006)
. The main reason for this overrepresentation is that arable farming which
is particularly present in this class results in lower carbon contents in the topsoil.
The agricultural most important EnZs are the Atlantic North and Central,
Continental and Pannonian EnZs (and to a lesser extent the Lusitanian and
Mediterranean EnZs) as they have relatively high shares of land used for agriculture
(mainly non-irrigated arable land). The Alpine North and South, Boreal, Nemoral
and Mediterranean Moutains EnZs show low proportions, even for the area which
is potentially suitable (Agri-mask class zero) for agriculture. Furthermore, the
proportion of agricultural land is highest on soils low in carbon and decreases with
increasing carbon content for most EnZs.
The agricultural land that is potentially suitable within the agricultural important
EnZs is mainly situated below 200 m. The southern environmental zones (Atlantic
Central, Pannonian, Lusitanian and Mediterranean EnZs) have a longer growing
season (>250 days with temperatures above 5°C) than the northern zones (Atlantic
North, Continental). The mean annual temperature range (temperature August
minus temperature August) for the Atlantic and Lusitanian EnZs is below 15°C
indicating a sea climate with relatively small temperature variations. The rainfall
minus potential evapotranspiration (ETp) summed over May, June and July
(summer drought) is less than 150 mm with as exceptions the Pannonian, Lusitanian
and Mediterranean EnZ with deficits from 150 mm up to almost 450 mm. The variation
of slope is small as the Agri-mask class zero land is land with slopes below 8%.
The available water holding capacity is around 0.15 with as exception the OCTOP
five class with relatively high available water holding capacity values. High shares
of deep soils (soils deeper than 80 cm) are found in the Atlantic, Continental and
Pannonian EnZs. Medium textured soils are most prominent in the agricultural
important AEnZ land types as they surpass 60% of the area.
For a more elaborate description on the variation between EnZs and within EnZs
for all AEnZ land types we refer to the report “Regional typologies of ecological
and biophysical context” (Hazeu et al.
2006)
.
Seamzones
Definition
For the use in SEAMLESS the agri-environmental zoning described in the previous
sections has been used as a basis for delineating spatial units (Seamzones) to be used
for modelling. For this purpose it was decided to combine three different layers:
