AGENZIA REGIONALE PER LA PROTEZIONE DELLAMBIENTE DELLA SARDEGNA ARPAS Andrea Motroni...
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Transcript of AGENZIA REGIONALE PER LA PROTEZIONE DELLAMBIENTE DELLA SARDEGNA ARPAS Andrea Motroni...
AGENZIA REGIONALE PER LA PROTEZIONE DELL’AMBIENTE DELLA SARDEGNA
ARPAS
Andrea Motroni
Climate, climate change and desertification in Sardinia
ENVIRONMENTAL PROTECTION AGENCY OF SARDINIA
AGENZIA REGIONALE PER LA PROTEZIONE DELL’AMBIENTE DELLA SARDEGNA - ARPAS
Agenda
• Climate characteristics
• Trends in climate
• Evidence of climate change?
• Climate and desertification
14TH European Seminar on Geography of Water - Cagliari, June 26th - July 7th, 2011
AGENZIA REGIONALE PER LA PROTEZIONE DELL’AMBIENTE DELLA SARDEGNA - ARPAS
The climate of Sardinia is generally classified as “Mediterranean”
Mediterranean climates are located between regions with a
tropical-desert climate and those with a marine-coast climate.
They generally lie between 30 and 40 degrees latitude.
These regions have hot-dry summers and mild-wet winters.
14TH European Seminar on Geography of Water - Cagliari, June 26th - July 7th, 2011
AGENZIA REGIONALE PER LA PROTEZIONE DELL’AMBIENTE DELLA SARDEGNA - ARPAS
•The Mediterranean Basin can be considered as a transitional area
between tropical zones, where seasons are determined by rainfall
occurrence, and temperate zones, where seasons are determined by
variations in temperature values.
•Consequence: there are great interseasonal variations in
precipitation amounts and in temperature values without the extreme
values typical of the two climatic areas (Chritchfield, 1983; Martyn,
1992)
14TH European Seminar on Geography of Water - Cagliari, June 26th - July 7th, 2011
AGENZIA REGIONALE PER LA PROTEZIONE DELL’AMBIENTE DELLA SARDEGNA - ARPASGeneral circulation
14TH European Seminar on Geography of Water - Cagliari, June 26th - July 7th, 2011
AGENZIA REGIONALE PER LA PROTEZIONE DELL’AMBIENTE DELLA SARDEGNA - ARPAS
•Mediterranean basin is characterized by the highest frequency
and concentration of cyclogenesis events.
•The majority of cyclones are formed in the gulf of Genoa,
probably because of Alps position and the high temperature
gradient between central-northern Europe and the
Mediterranean sea.
• In the transition periods of March-April and September-October
occur the most intense cyclogenetic rain events.
•Mediterranean climate is influenced by the presence of relevant
orographic systems along the Med. Basin -> major cyclones
activity
14TH European Seminar on Geography of Water - Cagliari, June 26th - July 7th, 2011
AGENZIA REGIONALE PER LA PROTEZIONE DELL’AMBIENTE DELLA SARDEGNA - ARPAS
The great seasonal differences are due to
northward migration of the upper limit of high
pressure cells typical of subtropical areas.
In Summer, high pressure cells reach the
Mediterranean area causing atmospheric
stability which can lead to typical arid
subtropical conditions in June, July, August
with high maximum temperature values.
In the Winter season, the cells leave the Mediterranean sea and lay in north Africa
region. Humid air fluxes and cold Polar fronts characterize autumn, winter and partly
spring seasons in this area
14TH European Seminar on Geography of Water - Cagliari, June 26th - July 7th, 2011
AGENZIA REGIONALE PER LA PROTEZIONE DELL’AMBIENTE DELLA SARDEGNA - ARPAS
Climate in Sardinia
Except for general synoptic situations (atmospheric pressure)
- Complex orography
- Distance from the sea
- Wind
Can we talk about climate microregions in Sardinia?
14TH European Seminar on Geography of Water - Cagliari, June 26th - July 7th, 2011
AGENZIA REGIONALE PER LA PROTEZIONE DELL’AMBIENTE DELLA SARDEGNA - ARPAS
Temperature
AGENZIA REGIONALE PER LA PROTEZIONE DELL’AMBIENTE DELLA SARDEGNA - ARPAS
Temperature in Sardinia• Two transition periods before winter and summer
– September-November– March-April
• Depends on orography and altitude:– Thermal inversion in the valley areas– Eastern coast areas protected from cold north-western dominant winds
• Winter temperature values are mainly determined by the stabilizing effect of the sea (the inner areas of the island show a “continental” behaviour)
• Summer temperature values are influenced by stabilizing effect of anticyclonic cells and a north-south gradient can be seen (maximum temperature also west-east)
• Maximum and minimum temperature values show the same behaviour, but minimum temperature values show less variability
14TH European Seminar on Geography of Water - Cagliari, June 26th - July 7th, 2011
AGENZIA REGIONALE PER LA PROTEZIONE DELL’AMBIENTE DELLA SARDEGNA - ARPAS
July
Mean maximum temperature 1961-90
14TH European Seminar on Geography of Water - Cagliari, June 26th - July 7th, 2011
AGENZIA REGIONALE PER LA PROTEZIONE DELL’AMBIENTE DELLA SARDEGNA - ARPASMean minimum temperature 1961-90
January
14TH European Seminar on Geography of Water - Cagliari, June 26th - July 7th, 2011
AGENZIA REGIONALE PER LA PROTEZIONE DELL’AMBIENTE DELLA SARDEGNA - ARPASClimatic mean temperature 1961-90
14TH European Seminar on Geography of Water - Cagliari, June 26th - July 7th, 2011
AGENZIA REGIONALE PER LA PROTEZIONE DELL’AMBIENTE DELLA SARDEGNA - ARPAS
Precipitation
14TH European Seminar on Geography of Water - Cagliari, June 26th - July 7th, 2011
AGENZIA REGIONALE PER LA PROTEZIONE DELL’AMBIENTE DELLA SARDEGNA - ARPAS
Precipitation behaviour (where)
• 4 rain microregions:
– Gennargentu and Ogliastra
– Gallura and Limbara
– Campeda
– Sulcis-Iglesiente
• 3 dry regions
– Nurra
– Campidano
– Central-north Sardinia
(1961-90)
14TH European Seminar on Geography of Water - Cagliari, June 26th - July 7th, 2011
AGENZIA REGIONALE PER LA PROTEZIONE DELL’AMBIENTE DELLA SARDEGNA - ARPAS
Precipitation behaviour (how much)
• Minimum rain values:
– < 400 mm in the south west
• Maximum rain values
– 1200 mm (Gennargentu)
• Regional mean
- 600 mm
(1961-90)
14TH European Seminar on Geography of Water - Cagliari, June 26th - July 7th, 2011
AGENZIA REGIONALE PER LA PROTEZIONE DELL’AMBIENTE DELLA SARDEGNA - ARPAS
Precipitation behaviour (how)
• Frequency of rainy events– The areas where we have more than
80 days of rain/year are also the areas where it rains the most...
...except for the central-east coast
(1961-90)
14TH European Seminar on Geography of Water - Cagliari, June 26th - July 7th, 2011
AGENZIA REGIONALE PER LA PROTEZIONE DELL’AMBIENTE DELLA SARDEGNA - ARPASMean annual rainfall 1961-90
…where we have 50 days/year but rain>than average
14TH European Seminar on Geography of Water - Cagliari, June 26th - July 7th, 2011
AGENZIA REGIONALE PER LA PROTEZIONE DELL’AMBIENTE DELLA SARDEGNA - ARPAS
Rainfall regimes on daily basis 1961-90
14TH European Seminar on Geography of Water - Cagliari, June 26th - July 7th, 2011
AGENZIA REGIONALE PER LA PROTEZIONE DELL’AMBIENTE DELLA SARDEGNA - ARPAS
The north-west and south-west regimes are mainly frontal regimes (higher frequency, not very intense rain events)
The central-eastern regime is associated to south-eastern winds which impact the coastal orography in correspondence of cyclones that move along the coast of north Africa leading to convective rain events (less frequent, heavy rain)
14TH European Seminar on Geography of Water - Cagliari, June 26th - July 7th, 2011
AGENZIA REGIONALE PER LA PROTEZIONE DELL’AMBIENTE DELLA SARDEGNA - ARPAS
Wind
14TH European Seminar on Geography of Water - Cagliari, June 26th - July 7th, 2011
AGENZIA REGIONALE PER LA PROTEZIONE DELL’AMBIENTE DELLA SARDEGNA - ARPAS
Frequency of instantaneous wind
Fonni
MacomerAlghero
010
2030
0102030
0
10
20
30
0102030
0102030
0102030
01020304050
La Maddalena
0
10
20
30
Capo Frasca
Asinara
0
10
20
30
Decimomannu
0102030
Capo Carbonara
0102030
Carloforte
Perdasdefogu
Capo Bellavista
STAZIONE %
ASINARA 14.5
LA MADDALENA 11.0
ALGHERO 32.7
MACOMER 53.4CAPO FRASCA 24.3
FONNI 39.8
CAPO BELLAVISTA 25.3
PERDASDEFOGU 23.1CARLOFORTE 50.3
DECIMOMANNU 49.8
CAPO CARBONARA 3.9
Calm or variable wind
Percent of hours with wind blowing from different directions
Calm or variable wind (<1.5 m/s)
14TH European Seminar on Geography of Water - Cagliari, June 26th - July 7th, 2011
AGENZIA REGIONALE PER LA PROTEZIONE DELL’AMBIENTE DELLA SARDEGNA - ARPAS
Monthly means of instaneous wind speed
ALGHERO
0
2
4
6
8
10
1 2 3 4 5 6 7 8 9 10 11 12
mese
1961-1990
LA MADDALENA
0
2
4
6
8
10
1 2 3 4 5 6 7 8 9 10 11 12
mese
1961-1990
CAPO FRASCA
0
2
4
6
8
10
1 2 3 4 5 6 7 8 9 10 11 12
mese
1961-1990
CAPO BELLAVISTA
0
2
4
6
8
10
1 2 3 4 5 6 7 8 9 10 11 12
mese
1961-1990
14TH European Seminar on Geography of Water - Cagliari, June 26th - July 7th, 2011
AGENZIA REGIONALE PER LA PROTEZIONE DELL’AMBIENTE DELLA SARDEGNA - ARPAS
Monthly means of maximum wind speed
ALGHERO
0
2
4
6
8
10
12
14
16
18
20
1 2 3 4 5 6 7 8 9 10 11 12
mese
1961-1990
LA MADDALENA
0
2
4
6
8
10
12
14
16
18
20
1 2 3 4 5 6 7 8 9 10 11 12mese
1961-1990
CAPO FRASCA
0
2
4
6
8
10
12
14
16
18
20
1 2 3 4 5 6 7 8 9 10 11 12
mese
1961-1990
CAPO BELLAVISTA
0
2
4
6
8
10
12
14
16
18
20
1 2 3 4 5 6 7 8 9 10 11 12mese
1961-1990
AGENZIA REGIONALE PER LA PROTEZIONE DELL’AMBIENTE DELLA SARDEGNA - ARPASBreeze winds in Sardinia
AGENZIA REGIONALE PER LA PROTEZIONE DELL’AMBIENTE DELLA SARDEGNA - ARPAS
Trends and extreme events
14TH European Seminar on Geography of Water - Cagliari, June 26th - July 7th, 2011
AGENZIA REGIONALE PER LA PROTEZIONE DELL’AMBIENTE DELLA SARDEGNA - ARPAS
Anomaly Index of mean temperature
14TH European Seminar on Geography of Water - Cagliari, June 26th - July 7th, 2011
AGENZIA REGIONALE PER LA PROTEZIONE DELL’AMBIENTE DELLA SARDEGNA - ARPAS
Total Amount Precipitation Index
t
j
N
j
jjt
tt
t
P
NSPI
1
)(1
Pjt Total amount of P
j Mean (1961-1990)
j Standard Dev.
(1961-1990)
14TH European Seminar on Geography of Water - Cagliari, June 26th - July 7th, 2011
AGENZIA REGIONALE PER LA PROTEZIONE DELL’AMBIENTE DELLA SARDEGNA - ARPAS
Precipitation classes – Quality of rain
-3,0
-2,0
-1,0
0,0
1,0
2,0
3,0
4,0
1940
1945
1950
1955
1960
1965
1970
1975
1980
1985
1990
1995
idx
anno
1 - 5mm rain events
idx
m.mob.
-3,0
-2,0
-1,0
0,0
1,0
2,0
3,0
4,0
1940
1945
1950
1955
1960
1965
1970
1975
1980
1985
1990
1995
idx
anno
5 - 20 mm rain events
idx
m.mob.
-3,0
-2,0
-1,0
0,0
1,0
2,0
3,0
4,0
1940
1945
1950
1955
1960
1965
1970
1975
1980
1985
1990
1995
idx
anno
>50 mm rain events
idx
m.mob.
+7.9 +4.4
Precipitazioni fra 20 e 50mm (cumulato)
-3.0
-2.0
-1.0
0.0
1.0
2.0
3.0
4.0
anno
idxm.mob.
20-50 mm rain events
14TH European Seminar on Geography of Water - Cagliari, June 26th - July 7th, 2011
AGENZIA REGIONALE PER LA PROTEZIONE DELL’AMBIENTE DELLA SARDEGNA - ARPAS
Mean annual rainfall amounts (1951-2000)Mean annual cumulative reference
evapotranspiration (1951-2000)
Aridity trends
14TH European Seminar on Geography of Water - Cagliari, June 26th - July 7th, 2011
AGENZIA REGIONALE PER LA PROTEZIONE DELL’AMBIENTE DELLA SARDEGNA - ARPAS
4,6% semi-arid
29,8% dry sub-humid
7,5% humid
58,1% sub-humid
1951-00
Aridity Index = P/ETo
14TH European Seminar on Geography of Water - Cagliari, June 26th - July 7th, 2011
AGENZIA REGIONALE PER LA PROTEZIONE DELL’AMBIENTE DELLA SARDEGNA - ARPAS
•81-90 and 91-00 decades critical for mean temperature raising and rainfall deficit
•91-00 the worst due to more frequent extreme events
•51-60 slightly dry but with average temperature
•But...•1997-2003•2004•2009-2010
Aridity indexAridity indexFAO-UNEP (P/ETo)FAO-UNEP (P/ETo)
14TH European Seminar on Geography of Water Cagliari, June 26th - July 7th, 2011
AGENZIA REGIONALE PER LA PROTEZIONE DELL’AMBIENTE DELLA SARDEGNA - ARPAS
14TH European Seminar on Geography of Water - Cagliari, June 26th - July 7th, 2011
1996-2005
° driest period/50 ys but…
° carefulness in climate data managing
AGENZIA REGIONALE PER LA PROTEZIONE DELL’AMBIENTE DELLA SARDEGNA - ARPAS
Standardized Precipitation Index a 24 mesi
y = -0.004x + 1.1424
-3
-2
-1
0
1
2
3
4
52 54 56 58 60 62 64 66 68 70 72 74 75 77 79 81 83 85 87 89 91 93 95 97 98
anno
SP
I a 2
4 m
esi
Precipitation trends SPI 1951-00
year
14TH European Seminar on Geography of Water - Cagliari, June 26th - July 7th, 2011
AGENZIA REGIONALE PER LA PROTEZIONE DELL’AMBIENTE DELLA SARDEGNA - ARPAS
Sardinia - Number of events with SPI<-1
05
101520253035404550556065707580
1953
1955
1957
1959
1961
1963
1965
1967
1969
1971
1973
1975
1977
1979
1981
1983
1985
1987
1989
1991
1993
1995
1997
1999
Year
Nu
mb
er
of
ev
en
ts
Extreme drought events
14TH European Seminar on Geography of Water - Cagliari, June 26th - July 7th, 2011
AGENZIA REGIONALE PER LA PROTEZIONE DELL’AMBIENTE DELLA SARDEGNA - ARPAS
Mean 1951-00 rainfall totalMean 1951-00 rainfall total
14TH European Seminar on Geography of Water - Cagliari, June 26th - July 7th, 2011
AGENZIA REGIONALE PER LA PROTEZIONE DELL’AMBIENTE DELLA SARDEGNA - ARPAS
UNCCD(1):“Land degradation in arid, semi-arid and dry/sub-humid areas, resulting from various factors, including climatic variations and human impacts” (UNEP, 1994)
Definition of “desertification”
(1): United Nations Convention to Combat Desertification
14TH European Seminar on Geography of Water - Cagliari, June 26th - July 7th, 2011
AGENZIA REGIONALE PER LA PROTEZIONE DELL’AMBIENTE DELLA SARDEGNA - ARPAS
…, i.e. desertification is a complex phenomenon strictly
dependent on climate
14TH European Seminar on Geography of Water - Cagliari, June 26th - July 7th, 2011
AGENZIA REGIONALE PER LA PROTEZIONE DELL’AMBIENTE DELLA SARDEGNA - ARPAS
Extreme climatic events: drought/floods
Pressures on the territory: overgrazing, uncontrolled urbanization/country areas abandonment…
Excessive exploitation of water resourcesWater contamination
Fires and deforestation
Causes of desertification in Sardinia
Soil salinisation
14TH European Seminar on Geography of Water - Cagliari, June 26th - July 7th, 2011
AGENZIA REGIONALE PER LA PROTEZIONE DELL’AMBIENTE DELLA SARDEGNA - ARPAS
Parent material
Soil texture
Rock fragment
Soil depth
Drainage
Slope gradient
Rainfall
Aridity index
Aspect
Fire risk
Erosion protection
Drought resistance
Plant cover
Land use intensity
Policy
VQIVegetation
Quality Index
SQISoil Quality
Index
CQIClimate
Quality Index
MQIManagement Quality Index
ESAs
14TH European Seminar on Geography of Water - Cagliari, June 26th - July 7th, 2011
AGENZIA REGIONALE PER LA PROTEZIONE DELL’AMBIENTE DELLA SARDEGNA - ARPAS
Sensitive areas to desertificationESAS
Sardinia
14TH European Seminar on Geography of Water - Cagliari, June 26th - July 7th, 2011
AGENZIA REGIONALE PER LA PROTEZIONE DELL’AMBIENTE DELLA SARDEGNA - ARPAS
Final remarks
- there are some signicative trends in changing temperature and rainfall values - they can be controversial both in sign (-/+) and in consistency – time and spatial scale problem
climate variability VS. climate change
- desertification is a more human induced process than climate-driven
further investigation on data and monitoring (for example) with bio-indicators are needed
14TH European Seminar on Geography of Water - Cagliari, June 26th - July 7th, 2011
AGENZIA REGIONALE PER LA PROTEZIONE DELL’AMBIENTE DELLA SARDEGNA - ARPAS
14TH European Seminar on Geography of Water - Cagliari, June 26th - July 7th, 2011
Thank you
AGENZIA REGIONALE PER LA PROTEZIONE DELL’AMBIENTE DELLA SARDEGNA - ARPAS
14TH European Seminar on Geography of Water - Cagliari, June 26th - July 7th, 2011