virginia puzzolo sten folving
DESCRIPTION
A GIS integration of topographic, geological and climatic data for the analysis of the Mt Etna forests distribution (Sicily, Italy). Virginia Puzzolo Sten Folving. The aim of this work. - PowerPoint PPT PresentationTRANSCRIPT
Virginia PuzzoloSten Folving
A GIS integration of topographic, geological
and climatic data for the analysis
of the Mt Etna forests distribution (Sicily, Italy)
The aim of this work
Geological substrata Volcano slopes Elevations Aspects Slopes Precipitation and temperature
was to provide a description of the forests distribution in the study area in relationship to some environmental characteristics :
Geological substrata and lava flows location play an important role in the forests distribution on an active Volcano
Volcano slopes are another characteristic which has to be considered when the analysis is conducted on a Volcano which has a conic shape
Differences exposures (aspect), availability of soil nutrients (slope) and humidity (elevation) are also important features
Precipitation and temperature are the first parameters that have to be considered to understand why a type of forest can survived or no in a certain area
Study Area Location
The study area is located in the eastern part of Sicily on the Mt Etna which is the biggest active Volcano in Europe with an extension of 1570 km2 and an elevation of about 3350 m a.s.l..
Evergreen oak (Quercus ilex) Deciduous oaks (Quercus pubescens
sl., Quercus cerris) Pine (Pinus laricio) Beech (Fagus sylvatica) Birch (Betula aetnensis) Chestnut (Castanea sativa)
The forests of the study area are mainly dominated by:
Evergreen oak forest
Pine forest
Beech forest Island (Dagala)
Forest-lava boundary
Data Layers Forest vegetation map
was extracted from the Mt.Etna vegetation map at scale 1:50.000 (Poli Marchese & Patti, 2000) that it was previously digitised using a standard image processing approach by supervised classification and post-classification smoothing (Lawrence et al., 1996);
Geological map at scale 1:50.000 (A.A.V.V., 1979) was digitised with the traditional hand method using the software ArcInfo and later it was converted from the vector to the raster format;
Elevations, Slopes and Aspects maps were derive from a 20 m resolution Digital Elevation Models using the spatial analyst ArcView software;
Temperature and Precipitation data were obtained from the study area meteorological stations beginning from 1960 to 1996.
Flowchart of the workVegetation
mapDTM
Forests mask
Elevations map
Slopes map
Aspects map
Forests map
Meteorological data
Forests spatial distribution analysis
Digitization
Correlation tablesVolcano slopes masks
Geological map
5 0 5 10 15 Kilometers
N
Evergreen Mediterranean vegetation forestsDeciduous oak forestsMixed oak and pine forestsPine forestsMixed pine and broadleaves forestsBeech forestsBirch forestsChestnut woods
Mt Etna Forests Map
Forests cover (%)
40%13%
4%
13%
3%6%
3%18%
Evengreen Mediterranean vegetation forests
Deciduous oak forests
Mixed oak and pine forests
Pine forests
Mixed pine and broadleaves forests
Beech forests
Birch forests
Chestnut woods
The forests distribution was strongly influenced by the volcanic activity of the Mt.Etna in different ways: it destroyed part of these forests
during the lava flows it always interrupts the soil evolution
with the pyroclastic materialthe volcanic substrata have different
petrographic characteristics depending on their origins
and from its shape.
5 0 5 10 15 Kilometers
N
Reworked pyroclastic material
Lava flows and tephra of 20th century, up to 1974
Lava flows and tephra of 18th and 19th centuries
Lava flows and tephra of 12th to 17th centuries
Undated but mainly historical lava flows and tephra
Lavas with well preserved surface morphology and associated tephra.Lavas with degraded surface morphology and poorly defined flow boundaries and associated tephraUpper tuffs and lahars
Lavas, tephra and tuffaceous sediments from the ancient alkalic centres
Products of the Ellittico and of Leone eruptive centres
Volcanics rocks from the eruptive centres of Trifoglietto
Geological Map of the Mt Etna Forests
Relationships between the Forest type and the Geological formations
Forest types
Geological formations
Reworked pyroclastic material 0,3 0,2 0,0 1,8 0,8 7,3 7,6 0,5
Lava flows and tephra of 20th century, up to 1974 0,3 1,6 5,8 1,3 3,9 3,3 5,3 1,5
Lava flows and tephra of 18th and 19th centuries 2,1 6,1 5,1 3,2 2,7 3,2 3,8 3,3
Lava flows and tephra of 12th and 17th centuries 21,0 20,5 15,5 7,7 7,0 28,8 0,6 4,1
Undated but mainly historical lava flows and tephra 24,9 12,1 6,3 12,5 22,8 11,1 36,7 15,1
Lavas with well preserved surface morphology and associated tephra
24,1 17,7 3,7 12,8 25,0 9,8 0,0 16,5
Lavas with degraded surface morphology and poorly defined flow boundaris; and associated
10,8 20,0 29,1 22,8 24,6 5,9 11,9 23,7
Upper and lower tuffs and lahars 3,0 1,6 0,8 0,0 0,0 0,2 0,4 17,5
Products of the Ellittico and Leone eruptive centres 9,3 17,0 33,7 37,8 10,3 13,4 33,8 11,9
Volcanic rocks from the eruptive centres of "Trifoglietto"
2,4 1,9 0,0 0,0 2,6 15,7 0,0 5,0
Lavas, tephra and tuffaceous sediments from the Ancient Alkalic centres
0,8 0,9 0,0 0,0 0,3 1,2 0,0 0,6
Eve
rgre
en M
edite
rrane
an
vege
tatio
n fo
rest
s
Dec
iduo
us o
ak fo
rest
s
Mix
ed o
ak a
nd p
ine
fore
sts
Pin
e fo
rest
s
Mix
ed p
ine
and
broa
dlea
ves
fore
sts
Bee
ch fo
rest
s
Birc
h fo
rest
s
Che
stnu
t woo
ds
Mongibello U
nit
Almost all of the Etnean forests are located on the Mongibello unit and mostly on the undated laves and on the products of Leone and Ellittico eruptive centres
the beech forests were also developed on the volcanic rocks of the "Trifoglietto" eruptive centre
the chestnut woods were planted on the upper tuffs and lahars
Forests distribution in relation to the Volcano slopes
Evengreen Mediterranean vegetation forests
0
25
50N
NE
E
SE
S
SW
W
NW
Deciduous oak forests
0
25
50N
NE
E
SE
S
SW
W
NW
Mixed oak and pine forests
0
25
50N
NE
E
SE
S
SW
W
NW
Chestnut woods
0
25
50N
NE
E
SE
S
SW
W
NW
Mixed pine and broadleaves forests
0
25
50N
NE
E
SE
S
SW
W
NW
Beech forests
0
25
50N
NE
E
SE
S
SW
W
NW
Birch forests
0
25
50N
NE
E
SE
S
SW
W
NW
Pine forests
0
25
50N
NE
E
SE
S
SW
W
NW
Elevation classes0-500500-10001000-15001500-20002000-2400
Elevations Map of the Mt Etna forests
Forests distribution in relation to the elevations
Evengreen Mediterranean vegetation forests
0,0 5,0 10,0 15,00
400
800
1200
1600
2000
2400
Deciduous oak forests
0,0 10,0 20,0 30,00
300
600
900
1200
1500
1800
2100
2400
Mixed oak and pine forests
0,0 20,0 40,0 60,00
300
600
900
1200
1500
1800
2100
2400
Chestnut woods
0,0 10,0 20,0 30,00
300
600
900
1200
1500
1800
2100
2400
Pine forests
0,0 10,0 20,0 30,00
300
600
900
1200
1500
1800
2100
2400
Mixed pine and broadleaves forests
0,0 10,0 20,0 30,0 40,00
400
800
1200
1600
2000
2400
Beech forests
0,0 10,0 20,0 30,00
300
600
900
1200
1500
1800
2100
2400
Beech forests
0,0 10,0 20,0 30,0 40,00
300
600
900
1200
1500
1800
2100
2400
m a.s.l.
%
The forests extend from the base of the Volcano to 1800-2300 m. a.s.l. and them altitude range changes in function of the forest type. The basal belt is characterised by the
Evergreen Mediterranean vegetation forests
The mountain belt is dominated by the other types of species and, in particular, by oak, pine, beech and birch in function of the different Volcano slopes.
SoutheastSouth Southwest West Northwest
Aspect classesFlat NorthNortheastEast
Aspects Map of the Mt Etna forests
Forests distribution in relation to the aspectsEvengreen Mediterranean
vegetation forests
0
15
30N
NE
E
SE
S
SW
W
NW
Deciduous oak forests
0
15
30N
NE
E
SE
S
SW
W
NW
Mixed oak and pine forests
0
15
30N
NE
E
SE
S
SW
W
NW
Chestnut woods
0
15
30N
NE
E
SE
S
SW
W
NW
Pine forests
0
15
30N
NE
E
SE
S
SW
W
NW
Mixed pine and broadleaves forests
0
15
30N
NE
E
SE
S
SW
W
NW
Beech forests
0
15
30N
NE
E
SE
S
SW
W
NW
Birch forests
0
15
30N
NE
E
SE
S
SW
W
NW
The aspects are strongly connected with the Volcano slope where the forest is located.
The evergreen and deciduous oak forests are the less restrictive
the other forests have, more or less, the same exposure of the them slope
Slope classes0 - 910 - 1920- 2930- 3940- 4950 - 5960- 69
Slopes Mapof theMt Etna forests
Forests distribution in relation to the slopes
Evengreen Mediterranean vegetation forests
0
20
40
60
80
Deciduous oak forests
0
20
40
60
80
Mixed oak and pine forests
0
20
40
60
80
Chestnut woods
0
20
40
60
80
Pine forests
0
20
40
60
80
Mixed pine and broadleaves forests
0
20
40
60
80
Beech forests
0
20
40
60
80
Birch forests
0
20
40
60
80
%
%
• They are normally located on slopes between 0 and 20 %.
• An exception is the beech forest located on the SE Volcano slope that it reaches, in some points, slopes with more of the 50 %.
All these forests prefer no very high slopes
The temperaturechanges uniformly with the altitude around the Volcano.
1918
17
1715
17
16
15
8
0 5 10 15 20
65
194275
285
348
405
560
589
590
680
698
750
750
780
1725
°C
0
10
20N
NE
E
SE
S
SW
W
NW
The rainfallchanges irregularly on the different Volcano slopes and it reaches the highest values on the eastern one because of its exposure to the sea.
49
67
47
38
82
82
96
42
108
48
101
57
62
56
62
0 20 40 60 80 100 120
65
194
275
285
348
405
560
589
590
680
698
750
750
780
1725
mm
-25
25
75
125N
NE
E
SE
S
SW
W
NW
Conclusions Geological, topographic and climatic
information is needed to extract useful information for improving forest management systems.
All these variables can be weighted and combined using GIS techniques that provide an efficient tool for handling multi-source data.
The results obtained during this study have showed how it is possible to combine all these environmental characteristics to better understand the forests distribution on an active Volcano, like Mt Etna
Thank you very muchfor your attention!