An Overview of Environmental Hazards Related to Crops in Greece

An Overview of Environmental Hazards

Related to Crops in Greece

By:Nicolas R. Dalezios

UNIVERSITY OF THESSALY LABORATORY OF AGROMETEOROLOGY

F R O S T I N G R E E C E

EVENTS, CLIMATOLOGY, DAMAGES,

FORECASTING-RISK ASSESSMENT

U N I V E R S I T Y O F T H E S S A L Y L A B O R A T O R Y O F A G R O M E U N I V E R S I T Y O F T H E S S A L Y L A B O R A T O R Y O F A G R O M E

T E O R O L O G YT E O R O L O G Y

An Overview of Environmental Hazards Related to Crops in Greece Prepared for COST734

FROST EVENTS

• Advection frosts

• Radiation frosts

• A combination of both

• THE MOST DAMAGING FROSTS ARE THE

ADVECTIVE FOLLOWED BY RADIATION FROSTS




CLIMATOLOGY OF FROST

Trewatha’s world map (1954) shows the average length of frost-free period.

Greece is divided in three zones

• Zone 2 Occasional winter frosts. (Islands, Southern Greece)

• Zone 3 Frost-free season > 240 days. (Central & parts of Northern

Greece)

• Zone 4 180 days < Frost-free season < 240 days (Northern Greece)




AGRICULTURAL DAMAGES (in thousands euros)

WHEATHER PHENOMENON

TOTAL (2001-2004)

WIND STORM 47,100

RAINFALL 177,850

HEAT WAVE 3,239

FROST 539,400

FLOOD 27,452

HAIL 179,005

SNOW 3,883

TOTAL 977,929

FROST CONTRIBUTION (%) 55




CROP DAMAGES & CONTRIBUTION TO TOTAL FROST INJURIES

CROP CATEGORY

DESCRIPTION CONTRIBUTION (%)

CITRUS ORANGES, GRAPE FRUITS

30-50

STONE FRUITS PEACHES 20-30

VEGETABLES 15-20

INDUSTRIAL PLANTS COTTON 15-20




FROST PROTECTION

• MAINLY PASSIVE METHODS ARE USED (cost-effective and more

beneficial than active protection methods)

• Wind machines protect < 10% of the citrus crop in Greece

• Sprinklers (over-plant and under-plant) protect < 20% of the citrus

crop




FROST FORECASTING – RISK ASSESSMENT

CASE STUDY: Frost risk mapping for the agricultural region of Central Greece




H A I L




CLIMATOLOGY OF HAIL IN GREECE

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Number of observed hail days for different areas in Greece.




HAIL DAMAGES

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Total annual compensations given to farmers from hail losses (prices are in million €)




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Hail loss percent from total compensations given to farmers




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Monthly distribution hail losses Percent of compensations Example: The year 2004.




0< 0.4 M €< 1 M €< 2 M €< 5 M €< 10 M €> 10 M €

PeachesCornVineyards

CottonVineyardsTomatoesCherries

Compensations given per prefecture for the year 2004 and main agricultural products hit by hail




HAIL PROTECTIONTHE NATIONAL HAIL SUPRESSION PROGRAMME (NHSP)

The three protected agricultural areas of NHSP.

Area Total Compensations(in M €)

Difference%

Average Period71-83

Average Period84-88

A1, Pella - Hmathia

1.31 0.55 -58

A2, Serres 0.34 0.15 -56

A3, Karditsa 0.96 0.18 -81

TOTAL 916,4 309,2 -66

Differences in compensations given before and during the NHSP




DROUGHT• Regional phenomena, referred to as "non events", since their

basic cause is the lack of precipitation events in a region over a period of time.

• Four drought categories: meteorological or climatological, hydrological, agricultural, and socioeconomic (American Meteorological Society, 1997).

• Drought responsive parameters: rainfall, soil moisture, potential evapotranspiration, vegetation condition, ground-water and surface-water levels.




Drought indices • Describe the magnitude, duration, severity, and spatial extent

of drought.• Based on meteorological and hydrological variables, such as

precipitation, streamflows, soil moisture, reservoir storage, and groundwater levels.

• Conventional drought indices based on ground measurements (e.g. PDSI, SPI, RDI, Rainfall Deciles, CMI, SWSI).

• Satellite drought indices based on remote sensed data (e.g. NDVI, VCI, TCI, VHI).




District climatic characteristics of Greece

1. Western coast and the islands of the Ionian Sea: significant precipitation, small annual temperature range.

2. West coast of southern continental Greece and the islands of the Aegean Sea: low winter temperatures, high summer temperatures and low precipitation.

3. Northern and Central continent: long duration storms, short drought periods, low negative temperatures during winter and large annual temperature range.

4. Crete and southern Greece: with small annual precipitation and droughts long duration.

5. Pindous Mountain range: high annual precipitation and strong gradients of precipitation and temperature with elevation.




Drought in Greece

• Drought severity increased from the northern to the southern and from the western to the eastern regions (Dalezios et al., 2000;Loukas et al., 2002).

Isoseverity map of droughts in Greece, from Z-index values, for three-month duration and five-year return period.




Case Study• Use of RDI and SPI in Naxos island, Mornos and Nestos

basin (Tsakiris and Vangelis, 2005; Tsakiris et al., 2006).

Normalised yearly RDI for Naxos meteorological station for the period 1955/56 – 1991/92.




Mornos case study: maximum water deficit and the most severe drought at Pentagi station during the years 1987-1995. The maximum annual drought intensity year 2000-2001.

Nestos watershed: maximum water deficit at Hryssoupoli station during the years 1988-1994. Severe drought, in 1986-1994 (Achladia station) and 1988-1996 (Ptelea station). maximum drought intensity for the year 1984-85 (Potami station).




Wheat and Drought

• Drought: major environmental factor limiting for wheat growth during the early part of its life cycle.

Plant Protection from drought• Rational regime of irrigation.• Alternative plant production.• Selection of tolerant plant genotypes.• Pumping of groundwater. • Construction of off-stream reservoirs to store surface water

sinks for collection of precipitation water. • Uses of desalinisation plants.




E X C E S S R A I N

• The duration and frequency of extreme rainfall rates are important climatological features to be considered in meteorology, agriculture, hydrology and civil engineering.

• Heavy precipitation events in the world wide have caused great damage to crop production.

• A warmer climate will be one in which the hydrological cycle will in general be more intense, leading to more heavy rain events (IPCC, 1996).

• Enhanced hydrologic cycle is responsible for the increasing flood damage.




Precipitation-related measures used for study of floods

• Total precipitation • Number of wet days per station • Number of extreme precipitation days (>2 inches) per station • Number of 2-day heavy precipitation events per station • Number of 3-day heavy precipitation events per station • Number of 5-day heavy precipitation events per station • Number of 7-day heavy precipitation events per station • Percentage of an area with much above-normal cold season (October–

April) precipitation • Percentage of an area with the number of wet days much above normal• Percentage of an area with much above-normal proportion of total annual

precipitation from 1-day extreme events.




Damages of Extreme Precipitation • Anoxic conditions by excessively wet soils (Kozdrόj and van

Elsas, 2000).• Increased risk of plant disease and insect infestation (Ashraf

and Habib-ur-Rehman, 1999).• Large losses of crop yield and production.

Damages after extreme precipitation




Excess Rain damages in Greece

Rainfall Extreme temperature Hail

FloodsWindstorms

Frost

Total map damages in Greece for all agriculture disaster categories in thousands € from 1986 to 2003.




Excess rain and Cotton Large damages are caused mainly in cotton and especially in

end-grow season at September. Effects in economy, quality and productivity of cotton in

Greece and especially in Thessaly plain where cotton production is significant.




F O R E S T F I R E SF O R E S T F I R E S




Types of Forest Fires • Ground fires.• Surface fires.• Crown fires.

Meteorological parameters such as rainfall, high temperature, low relative humidity and wind velocity have serious effect in the initiation and spread of forest fires.

Other factors affecting:• the variety and amount of fuel (vegetation and dead organic

material), • the fuel moisture and • the topography (altitude, slope).




Causes of Forest Fires

In Greece, the causes of wildfires are classified into three categories:

• Wildfires caused by natural causes.

• Wildfires caused by human activities.

• Wildfires caused by dubious-unknown reasons.

Causes of forest fires in Greece for the period 1985-1997 (Dalezios, 2006).

CATEGORY OF CAUSE Contribution in Percent (%)

1. Negligence

1.1 Cigarettes stubs or matches 14,0

1.2 Burning of stubble 21,1

1.3 Military shooting exercises 0,6

1.4 Trains and electrical lines 0,4

1.5 Sparks from machinery 2,7

1.6 Overheating 2,5

1.7 Bees smoking 0,6

1.8 Campers 1,5

1.9 Burn of wastes and other causes

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1. Sum of causes due to negligence

48,4

2. Arsons 27,2

3. Natural causes 2,1

4. Dubious or unknown causes 22,5




Burned Area in Greece

Burned Area per type of forest coverage

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Wildfire Statistics for GreeceBasic statistics of forest fires in Greece for the period 1955-1996 (Dalezios, 2006)

YearMEAN NUMBER OF FIRES PER YEAR 991

MAXIMUM NUMBER OF FIRES 2,406 1993

MINIMUM NUMBER OF FIRES 304 1959

MEAN BURNED AREA (ha) 28,193

MAXIMUM BURNED AREA (ha) 110,501 1988

MINIMUM BURNED AREA (ha) 2,221 1959

Need for protection (prevention and suppression), monitoring, forecasting and risk assessment.




K-study in Penteli, Greece (Domenikiotis et al. (2002). • Technique based on satellite derived NDVI.• NOAA/AVHRR and Landsat TM data.

Monitoring and Mapping

(a) (b)Images formed by NOAA/AVHRR data before (a) and after (b) the forest fire in

Penteli, Greece. Bright areas in the first image indicate the presence of vegetation and the gray areas correspond to suburbs of Athens and the sea




Burned areas: dark red, Vegetation areas: green (Landsat TM images).

Concluding, NOAA/AVHRR data can be used for operational monitoring and assessment of damaged area in near real-time with high degree of accuracy. Landsat TM is much more accurate (Domenikiotis et al. (2002).

Monitoring and Mapping

(a) (b)

Landsat TM color composites images (7,4,1) before (a) and after (b) the forest fire in Penteli, Greece. This band compilation highlights the burned area.




Forecasting and Risk AssessmentK-study in Pelio, Greece (Spanos et al. 2002). • Use of three meteorological parameters and

Angström’s index for risk assessment.• NDVI for detection of the burned areas.

Meteorological parameters and Angström’s index during the initiation of fire.

Station/Parameter Volos Velestino ZagoraAir Temperature (C) 28.3 29 27Relative Humidity (%) 30.3 33 45

Wind speed (ms-1) 2.6 0.3 0.8Angström’s index 1.4 1.5 2.3

The study highlighted the importance of local meteorological conditions in the fire risk assessment.




GRAPES PEST AND DISEASES

1. Hadromycosis-Bertisillioseis / Verticillium dahliae, Verticillium albo-atrum

2. Bacillar necrosis / Xylophilus ampelinus 3. Botrytis (ash decay) vine / Botryotinia fuckeliana4. Esca or Polisporiash / Phellinus igniarius, Stereum hirsutum (esca,

black measles, apoplexy)5. Necrosis of arms / Eutypa lata6. Mildew of vine (downy mildew) / Plasmopara viticola7. Decays of fruits from penikilla / Prnicillium digitatum, Penicillium

italicum, Penicillium expansum8. Fomopsi or exkoriosi of vine / Phomopsis viticola9. Oidio of vine / Uncinula necator




Geographical distribution of indemnification for damages of mildew in Greece (source ELGA).




Protection measurements • The care of soil and the fertilization • Corridors and areas released exempted of pests • Cares of leafage • Direct means of plant health protection (combating) • Estimate of danger and observation of enemy or pathogenic




The use of models for protection of diseases

• PERO Model simulates the infection cycle development according

to agrometeorological conditions, allowing the best timing for fungicide treatment.

• PLASMO model Simulates the inflection cycle development and

diseased leaf area






Ν. Aghialos 2000

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PERO Model Application Results

for the area of N. Aghialos in Greece for the year 2000


An Overview of Environmental Hazards Related to Crops in Greece

Documents

cost734climatology of

days frostfree season

hail losses prices

frost risk mapping

cost734agricultural

average period71

cost734hail loss percent

main agricultural products