with the Common Database on Designated Areas
(CDDA) of the European Environment Agency
(http://www.eea.europa.eu/data-and-
maps/data/natura-6#tab-european-data, last accessed
February 1, 2017).
Regarding to the information needed to develop
the LULC scenarios, maps from CLC project for the
years 1990, 2000 and 2006 were downloaded
(http://centrodedescargas.cnig.es/CentroDescargas/b
uscadorCatalogo.do?codFamilia=02113, last
accessed February 1, 2017). We did not consider the
most recent map (CLC 2012) because it is still under
review.
A collection of auxiliary geographic data was
taken into account in order to map the driving
factors and the restrictive and incentive factors
during design of future LULC scenarios. A Digital
Elevation Model (raster 30 m GMES RDA, EU-
DEM) was used to generate altitude and slope maps.
Roads, rivers and railway stations (Numerical
Cartographic Base 1:100,000, obtained from the
Spanish National Geographical Institute) were
considered to calculate cost of transport and
distances to the city of Madrid, to other cities, to the
airport and to the roads themselves. Other
information used was the lithological map of
Madrid, the map of public-utility forest areas
(Regional Government of Madrid), PA zoning in the
region (Autonomous Body for National Parks) and
specific legislation on land and territorial planning
(General Urban Land Plan for Madrid for 1997, Law
9/2001 of 17 July on land in the Region of Madrid,
Law 9/1995 of 28 March on measures for territorial
policy, land and planning, and Law 3/1991 of 7
March on roads in the Region of Madrid).
CLC vector maps were converted to 50*50m
pixel size raster format. To simulate future LULC in
2025, a simplification of CLC legend was made,
from CLC level 3 to seven categories was made: (1)
urban fabric, (2) industrial and commercial, (3)
arable land and permanent crops, (4) heterogeneous
agricultural areas, (5) forests, (6) shrubs and
herbaceous vegetation, and (7) others (open spaces
with little vegetation, wetlands and water bodies).
Using CLUE three different scenarios were
developed: (a) “business as usual” scenario, (b)
economic crisis scenario and (c) green scenario. The
first one, shows what would happen if the past trend
observed during 1990-2000-2006 was to continue
until 2025. The crisis scenario shows what would
happen if the economic crisis in Spain and the region
of Madrid was to continue until 2025. The green
scenario shows what would happen if there were
more active reforestation policies and if greater
importance was placed on the natural environment.
It does, however, take into account that Madrid is an
urban region and that built-up areas will continue to
grow. This means on the one hand, that greater
protection is offered to natural uses than in the past
and, on the other, that greater growth is assigned to
built-up land (for more information see Gallardo
2014; Gallardo et al. 2016).
LULC and driving factors were related by means
of logistic regressions (LR). Previously, correlations
between the selected variables were observed by a
Pearson’s correlation analysis. The future demand
for each land use was assigned specifying the
number of hectares for each land use in 2025, based
on what had happened in previous years. For the
trend scenario, each LULC type evolves according
to the observed past trend. For the economic crisis
scenario, experts’ opinion was included as input
data. A questionnaire was distributed among 117
experts that were asked about how much the
different LULC types could grow or decrease under
an economic crisis scenario and where these LULC
changes could preferentially be located. Finally, the
green scenario was calculated as a halfway scenario
between the trend and the economic crisis scenarios
for agricultural and artificial LULC types while for
forest and shrub and pastures, an increase of about
13 and 0.2 %, respectively, comparing to 2006 is
defined.
Calibration processes were taken into account in
order to improve the scenario results. This was done
in different ways: changing the future
demand/extension of each LULC, changing the
conversion matrix, selecting the driving factors, etc.
Taking the sequence of maps 1990-2000 as a base, a
simulation of a land-use model in 2006 was carried
out and compared it with the real map for 2006. The
amount of land-use change, the driving factors used
and/or the size or weight of the neighbourhood were
changed in order to obtain a better result. For
validation, comparisons in terms of quantity and
location were analysed. Kappa statistics, K Location
(location) and K Histogram (quantity) (Pontius
2000; Van Vliet 2009) was used. Results were
compared with a null model and a random model.
Values and maps of hits, misses and false alarms
were obtained (Eastman 2012; Sangermano et al.
2012). (See Gallardo, 2014)
PAs were analysed regarding to their level of
priority. Areas that overlapped are classified as areas
of greatest protection. In descending order, the level
of priority is as follows: (1) Nature Reserve, (2)
National Park, (3) Regional Park, (4) SAC, (5) SPA,