Chapter 12
Natural Disasters
Summary
Natural disasters in Georgia take place onquite a large scale and with high frequency
ofrecurrence due to complex geological and geographical conditions in Georgia. The frequency
of natural disasters has increased in the recent past and this increase is considered to be a
consequence of the effects of global climate change. In addition to climate change, there are
other man-made pressures which contribute to the frequency of natural disasters, such as
deforestation and overgrazing of pastures.To avoid the loss of human life and in order to
decrease the economic damage caused, an Early Warning System is under development ,
which will be based on appropriate monitoring, analysis and forecast of these phenomena.
Introduction
Natural disasters cause considerable damage to the economies of countries and often lead to
human casualty. Protection of the populationssafety , the integrity of infrastructure and
productivity of lands, are the main socio-economical and environmental concerns pertaining to
natural disasters by administrations all over the world, and in particular mountain countries
where such incidents are more previlant. The frequency of natural disasters has increased in
the recent past and this is thought to be primarly related to effects of global climate change, This
problem became more acute during the last period because of global climate changes.
Aproximatly 60% of all types of natural disasters are caused by extreme weather events, and
result in more than 80% of damage caused. Climate change is causing more frequent and more
extremeweather events which result in the occurance of more natural disasters such as
landslides and floods.
State regulation
The resolutions of the World Summit held in Johannesburg (South Africa) under the auspices of
the United Nations in 2002 and the World Conference on Disaster reduction held in Hyogo
(Japan) in 2005 are the basic guidelines for minimising the risk of natural disastersand for
determining appropriate mitigation measures.
Many countries have developed National Natural Disaster Management Programs.Taking into
account the urgent need, the Common Data Base and Management Strategy have been also
developed at international level. In 1990, the United Nations announced the Decade of Natural
Disaster Investigations and Mitigation Measures, and declared 2002 as International Year of
Mountains. As a result, many countries have developed National Programs on Mountain
Development and the Prevention of Natural Disasters, and in addition many European countries
signed the Alpine Convention, devoted to the sustainable development of mountanious region
of Alps.
Georgia joined these developments in 1995 (Decree #36) and established the National
Committee for conducting the Decade of Natural Disaster Mitigation Measures. Earlier, in 1993,
the Government adopted the special Decree (#967) on Establishing a State Environmental
Monitoring System for Georgia, and designated the Ministry of Environment and Natural
Resources of Georgia as the bodyresponsible for coordinating the monitoring system. In 1997
the President of Georgia issued aspecial Order (#66) on Protection Measures against the
Development of Dangerous (Geological Processes and Protection Measures for Lands and
Ground waterfrom suchprocesses. In 1999 the Georgian Parliament adopted the Law on SocialEconomic and Cultural Development of the High Mountain Regions, as well as the Laws on
Environment and Soil Protection, where the negative impact of natural disasters was underlined.
Later, in 2007, the President issued a special Order (#542) on the Protection of the Population
and Territory from Emergency Threats caused by Natural and Man-madeDisasters. Recently a
revised version of the Review/description of the Natural and Man-madeThreats in Georgia. The
management of Natural Disasters has been identified as a key priority in the dratf Second
National Environmental Action Program of Georgia.
2.Natural Disasters in Georgia
Among the mountaneous regions Georgia is one of the counties most affected by geological
disasters and the damage they cause to the population, agricultural lands and the infrastructure
(Map1). Landslides, mudslides and water-caused erosion are the most frequent natural
disasters that occur in Georgia.
The geographic location of Georgia and its complex topographyresults in atmospheric
conditions which give rise to extreme weather conditions.
Map1: Settlements under the threat of geological phenomena in Georgia
Landslides can occur in almost all
locations in Georgia,from the sea
side up to high mountain regions.
Aproximatly1,5 million ha of the
country territory is at risk of
landslides.
Landslidesare
especially pronouncedin areas with
a high degree of slopes, and areas
of
tertiary
marine-molasic
sediments, and Jurassic clay
shale.
Map 2: Landslide risk zones in Georgia
Mudslide have been observedin
Georgia in approximately 3000
erosive
water
courses.
An
estimated 2 million hectares ofthe
territory of Georgia is at risk of
mudslides.
The most intensive
and
frequentmudslides
are
observed in the Caucasus ridge
areas which are underlain by clay
shale,
Tsiv-Gombori
and
Saguramo-Ialno ridges and AjaraTrialeti mountain system.
Map 3: Mudslide risk zones in Georgia
Almost all rivers inGeorgia are
prone to high levels of flow and
flooding. The rivers of Imereti,
Samegrelo, Guria, MtskhetaMtianeti, as well as the rivers of
Mtkvari basin (including
Alazani)are at most risk of flooding.
Map 4: Areas at Risk of Flooding in Georgia
Droughts are observed almost at
the whole territory of Georgia.
Drought conditions are frequent
and pronounced in theShidaKartli
and QvemoKartly regions, in
Kakheti, and ZemoImereti
Map 5: Regions Pron to Drought in Georgia
Frequent strong winds are
observed in the Caucasus ridge
zones of, Kolkheti lowlands,
ZemoImereti, ShidaKartli, Tbilisi,
GareKakheti, and SamtskheJavakheti regions
Map 6: Areas with High Wind Speeds in Georgia
.
Over half the territory of Georgia is
at risk of snow
avalanches.Avalanchesare
especially intensive in the mid and
high mountain zones. The most
risky zones are the western and
central segments of the Caucasus
and Guria-Ajara mountains.
Map 7: Risk of avalanches in Georgia
Hail falls are observed throughout
all of Georgia. The intensity and
frequency of the hail falls are
higher in East Georgia.
Map 8: Areas with intensive hail fall in Georgia
Changes in the frequency of natural disasters
The frequency of natural disasters has increased significantly in recent decades, primarily due
to the impacts of global climate change.
•
Up until 1995 floods occurred on average 3 to 5 times per year. Since 1995 this
recurance has varied from between 2 to 20 times per year, with a range of between7 to
20 occurances observered over the period 2007 to 2009.The damage caused by the
flooding during the last 3 years was calculated as 110 millions GEL. In addition there
were human casualtieswith the loss of seven lives.
•
Historicaly prolonged droughts were observed once in every 15 to 20 years, while during
more recent times the frequency of this phenomenon has increased by a factor of three
with prlonged droughts now occurring aproximatly every six years. The economic impact
of dorughts on agriculture over the period 1995 to 2009 is extimated as 400 million GEL.
•
The increasing frequency and intensity of avalanche’shas been noticed since 1970.
Large slides wererecordedduring the winter period in 1970-1971, 1975-1976, 1986-1987,
1991-1992, 1996-1997, and 2004-2005. The areas of Svaneti, Mountain Ajara, Tusheti,
Kazbegi, and Dusheti districts were significantly damaged, and 176 people have died.
More than twenty thousand people were displaced form their homed over the
periodfrom1970 to 1987. Over the 2007 to 2009 period there were twenty potential
avealanch events, and during this period three people died as a result of avalanches.
•
The most intensive hail falls were observed in 1983, 1987, 1993, and 1997. According to
incomplete data, damage caused by the hail falls during the last 14 years is estimated as
150 million GEL. Twenty seven hail falls were observed over the period 2007 to 2009,
which caused the economic damage of approximately 20 million GEL.
•
Strong winds were recorder between 1 and 4 times per year over the period 1995 to
2006. Form 2007 to 2009 the frequency of the strong winds had increasedto 6 to12 times
per year. Over this period the damage caused by the strong winds was estimated as
aproximatly12 millions GEL and 9 people have died.
•
In 1982 coastal erosion occured on 220 of the total 320 km of the Georgian Black Sea
coastal line. The alarming rate of coastal erosion was arrested somewhat by applying the
artificial beach-forming method of increasing the solid sedimentation process. Between
1982 and1990 costal erosion was confined to aproximatly 8 km and the total area of
newly created beaches reached 150 hectars. Since 1992 the ‘artificial creation’ of the
coastal line has ceased and consequently the coastal erosion processes has resumed at
vunderble areas which were previously protected. Today this process is especially grave.
Areas of high amenity are being significantly impacted,landslides take place in many
districts including Mussera, AkhaliAthoni, Eshera, Gonio, and Tsikhisdziri.
Landslides and mudslides are the most significant natural disasters, the incidents of which are
increasing year on year.
•
•
By 2009 aproximatly 53 thousand areas damaged or threatened by gravitational
landslides have been identified. These areas include up to 2 000 settlements and 2530% of the road and pipeline network.
It is estimated that on an annual basis mudslides cause damage to the value of
approximately 100 million USD.Extreme mudslide events can cause damages of
hundreds of millions of dollars. For instance, the economic damage caused by
mudslides in mountains of Ajaraover the1982 to 1998 period wasaproximatly 500 million
USD. Economic damage caused by mudslides at a national level exceeded one billion
USDover the period 1987 to 1991, while damage caused by mudslides during 1995 to
2008 was over 330 million USD and in addition 43 people have died. There were
numerous glacial mudslides in river Tergi basin the most tragic of which occired in2002,
when the glacial mudslide passed from the mountain Mkinvartsveri through the river
Ka
armadoni canyon
c
killiing 130 pe
eople. In 20
007 the De
evdoraki gla
acial muds
slide dama
aged
a 500
5 metre long sectio
on of the Georgian
G
Military
M
Roa
ad within th
he river Da
ariali range
e.
Up until th
he last deccades of tw
wentiethcen
ntury the occurance of
o extreme
e lanslides and mudslides
more or le
ess conform
med to a defined
d
cyccle which was
w depen
ndent on th
he particula
ar geologiccclimatic co
onditions of
o the areas in question. The frrequency of
o such occcurances was
w betwee
en
once everry 2 -5 yea
ars on averrage. Since
e 1990, the
e extreme mudslidess or lanslides occurr each
e
year has exceeded
e
this averag
ge occuran
nce, with th
he intervalss between extreme occurrence
o
es
shortening
g year on year.
y
As a result, the
e areaaffec
cted by succh mudslide
es is gettin
ng wider evvery
year involving new settlements
s
s and engineering co
onstruction
n (Tables 1, 2).
mln. ha/
mln.ha
a
5
4.5
4
3.5
3
2.5
2
1.5
1
0.5
0
1970
1977
1981
1987--88
1991-92
1997
2005
weli/Year
Y
Figure: Arrea of Geo
orgia impaccted bynatu
ural geolog
gical proce
esses.
raodeno
oba
60000
50000
40000
30000
20000
10000
0
1942
1960
0
1963
1
1968
1972
1981
1987-89 1991-92
2000
2005
5
weli
Figure: Nu
umber of la
angslides recorded
r
b years
by
raodenoba
a
3000
2500
2000
1500
1000
500
0
1960
1970
1981
19
994
2000
2005
weli
Figurre: Numberr of mudsliids recorde
ed by years
rs
25
20
15
10
5
0
wlebi
Figure: Frrequency of
o flooding observed in Georgia
a between 1961 and 2009
Tveebi
7
6
5
4
3
2
1
0
1960
1962
1964
1966
1968
1970
1972
1974
1976
1978
1980
1982
1984
1986
1988
1990
1992
1994
1996
1998
2000
2002
2004
2006
2008
wlebi
SemTxvevaTa ricxvi
Figure: Frequency of drought periods in Georgia between1960 and2009
14
12
10
8
6
4
2
0
1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 wlebi
2009
Figure: Occurance of strong winds in Georgia between1995 and2009
SemTxvevaTa ricxvi
60
50
setyvis mosvvlis
SeemTxvevaTa ricxvi
40
aTasi ha
30
20
10
0
wlebi
196719691971197
731975197719
97919811983
319851987198
8919911993199519971999
920012003200
0520072009
Figure: Frrequency of
o hail fallss and areass of agriculltural landss damaged
d between 1967 and 2009
Table 1: Landslide
es and mudslides
m
d
detected
in
i urban areas of Georgia during
d
reg
gional
al monitorin
ng between
n 1980 and
d1994
geologica
Years
Acttivated and
d newly de
eveloped
lan
ndslides
Develop
ped mudslides
19801986
2684
1521
19871988
2581
824
19891991
2823
594
19921994
1203
674
9291
3613
Total
Table 2: Intensity of landslid
des and mudslides
m
identified in urban areas of Georgia during
d
regional geological
g
m
monitoring
g between 1995 and 2009
2
and the
t estimated resultin
ng damage
e
Casualties
Mudslide frequency
Approximate direct
damage, mln . GEL
Casualties
Total damage, mln.
GEL
Threatened units
Approximate direct
damage, mln . GEL
Mudslide
Manifestation
(activated and newly
developed)
Landslide
1995
670
132
6
250
96
12
228
179
274
195
1996
610
80.3
3
165
27
5
107.3
232.3
403
626
1997
871
102
2
335
44
7
146
336.5
458
227
1998
543
67
5
173
20
6
87
229.6
370
159
1999
56
12
1
27
4.5
-
16.5
137.8
157
314
2000
65
13
1
23
3.0
-
16
162.2
240
207
2001
75
15
-
26
4.0
-
19
127.5
191
127
2002
69
13.8
1
23
2.5
2
16.3
147.9
203
193
2003
71
14.5
3
28
4.0
-
18.5
106.5
90
207
2004
949
147
4
258
28
2
175
16289.2
755
6042
2005
603
96
-
155
9.0
4
105
7589.6
473
3682
2006
356
70.5
1
63
9.0
-
79.5
3172.5
531
2066
2007
136
20.5
-
104
11.5
-
32
1389.1
269
707
2008
311
48
-
126
15
8
63
1387.7
392
1198
2009
323
63.5
1
193
16.5
3
80
8232.3
521
2696
Total
5708
895.1
28
1949
294
49
1189.1
397219.7
5327
18646
Years
Damaged
agricultural
land, ha.
Number of
settlements
Living houses
weli
Floods
Drought
Storms
Avalanches
hail falls
Damage total mln GEL
Number of occurances
damage mln GEL/number of dead
duration (months)
damage mln GEL
Number of occurances
damage mln GEL/number of dead
number of potential occurances
damage mln GEL/number of dead
Number of occurances
damage mln GEL
1995
4
3,2/1
_
_
2
0,5
8
3,2/2
7
12,7
19,6/3
1996
11
28,5/1
1,5
17,0
4
4,0/5
6
3,8/3
11
17,0
70,3/9
1997
12
38,0
2
26,0
3
1,0
10
4,2
14
35,0
104,2
1998
2
2,0/1
1
6,0
3
72,0/5
9
3,9/2
12
8,5
92,4/8
1999
8
30,5/1
_
_
2
3,5
12
3,7/1
9
6,9
44,6/2
2000
2
2,0
6
300,0
2
1,0
7
2,1/1
7
5,8
310,9/1
2001
4
4,1
2,5
21,0
1
0,1
6
3,5/1
8
10,4
39,1/1
2002
16
78,7
_
_
2
0,6
8
1,5
8
6,8
87,6
2003
6
4,2/2
_
_
1
0,1
8
2,1/2
7
6,0
12,4/4
2004
10
20,5/1
_
_
4
0,8
10
4,8/1
11
12,5
38,6/2
2005
20
80,0/4
_
_
3
0,4
14
4,5/3
19
6,9
91,8/7
2006
8
15,0/1
1,5
5,0
3
0,3
12
2,5
11
6,2
29/1
2007
7
40,3/1
-
-
6
1,1/1
10
3,0/1
7
5.0
2008
16
38/1
-
-
5
2.9
4
1.9
5
2.9
20
30/5
1,5
6
12
8/8
6
2,8/2
15
9.5
56,3/15
146
415/19
16
381,0
53
96,3/19
130
47,5/19
151
152,1
1091,9/57
2009
sul
49,4/3
45,7/3
Table 3: Extreme hydro-meteorological phenomena identified in Georgia between1995 and
2009 and the estimated damage caused
Suspected causes of the Increased frequency of natural disasters
The recent increases in the number of geogicially related natural disasters occurring in Georgia
is thought to have been caused by some or all of the following circumstances:
1. The occurance of Earthquakes of high intensity;
2. The effects of global climate change, in particular increased rainfall temperature and
humidity, which can initiate or agrivategeological events such as mudslides, soil erosion
etc (see the details in ch 3)
3. The impacts of human activity, particularly those of mining, hydro-electricity plants and
urban development are of particular concern, as outlined below:
Mining industry
There are over 5 000 mines in Georgia, the majority of which are open-cast.Mining activities by
their nature have a significant interaction with the geology and hydrogeology of a region. If
poorly managed this impact can lead to many negative environmental impacts such as
rockslides, mudslides, caving-in, alteration of the hydrodynamics of the area and indeed
pollution of the ground and groundwaters. The following sites are particularly important in this
regard:
•
During the hundred year period of exploitation of the Chiatura manganese deposit, 130140 million cubic metres of ground has been transformed and moved, and an area of
over 200 square kilometres has been affected. Intensive rockslides and landslides
developed in this area and dammaged hundreds of hectares of agricultural lands,
destroyed numerousvillagesincludingmore than a thousand ofdwellings. Total length of
mines of the Chiatura deposit is 200 km.
•
At the Tkibuli coal mine aproximatly 1,5 million cubic metres of ore was excavated and
processed annually. In result of intensive exploitation of the deposit, the surface
subsidence above the working tunnels reached 10-15 m.
•
At the Madneuli barite-poly-metal deposit, open cast mining is conducted over an area of
105 ha and to a depth of 200 m on average. Here the landslide of 1,3 million m3 volume
has been developed.
The impacts of water relate infrastructure
The constructiin of Hydro-electric power plants has had a significant impact on the black sea
costal area. Before it was dambed the river Enguri carried 15 million cubic metres of solid
material down to the Black sea each year. Construction of the dam prevented this solid material,
which was the building material for the beaches on the coast, form being carried own stream. In
the absence of replacement material comming down river, the former estuary area and the
adjacent coastal area were eroded away at a rate of 10 meters per year and more.
A similar situationis expectable to arise in the Ajara coastal zone due to dam construction on
river Chorokhi (in Turkish territory). Before dam construction, the river Chorokhi carried 2,5
million cubic metres of beach forming solid materialto the sea each year, while after construction
this solid sediments were removed. The effects of removal of this beach forming solid sediments
is observed at the Chorokhi – Batumi coast where the coastline is being eroded at a rate of
several meters per year.
There are currently 44 artificial water bodies in the country with total length of the coastal line
over 600 km. Aproximatly 25% of this coastal line is either damaged by landslides, or is under
the threat of landslides. Due to changes in river hydrodynamics and increased erosion these
artificial water bodies are experiencing Intensive silting processes which in turn gives rise to
more frequent flooding of the adjacent areas. For instance, the volume of Gumati water
reservoir has been decreased by 70% during the first 10 years of its operation; Lajanuri
reservoir volume has been decreased by 35% during the 13 years of operationand in addition
landslides and mudslides periodically damage the adjacent settlements. In particular, the
mudslide developed in March 2010 severely damaged 25 dwellings in the village Lajana.
Urban development
Civil constructioncan have a significant impact on the geologic environment, which can
transform natural landscapes, create artificial grounds and slopes, change surface water
coursesand ground water regimes. Made ground with debths varing from 2 to 20 metres arise in
many towns. Residential housing and other buildings constructed on the slopes of such grounds
often give rise to gravitational landslides, ground subsidence, and other negative processes.
During the last 40 years over 60 landslides of this type have been recorded within the limits of
Tbilisi (including area adjacent to Mukhatgverdi cemetery, Khevdzmari, Libani, Mamadaviti,
Gldani, etc.).
3. Main challenges
It is important to ensure that effective management measures are put in place in order to
prevent and mitigate the possible negative consequences of natural disasters. The key
activities here are monitoring, preparadness and timely warning-informing the public.
In order to minimise the negative consequences of natural disasters it is very important to
determine the location, type and scale of the expected phenomenon, as well as the predicted
impact of such an event on the population and infrastructure. This would allow the preparation
of action plans which would minimise the impact of such an event. These action plans should
include the measures that to be undertaken at a regional, municipial and local level. Part of
those measures include complex infrastructural works (such as strengthening the coasts or
construction of artificial beaches) which are to be implemented well in advance. The other part
includes responsive measures to the disasters.
Making the public fully aware of the risks associated with natural disasters and what can be
done to minimise these risks is essential, as is the provision of timely information to the public
when such an event is forcast. It is essential to inform people on simpe preventive or protective
measures which could easily be implemented by municipalities, communities or residents
themselves. Therefore establishing an effective early warning system is essential. An
appropiate networks of hydro meteorological monitoring and geomonitoring and the associated
data management and forcasting capabilities are essential to adequately assess the risks of
natural hazards and predict their occurance..
In recent years, certain measures in this direction has been undertaken. The hydrometeorological observation network was extended to some degree, hydrological forecastingwas
improved, the geological processes all over the country were catalogued and defined the risk
factors of associated with their occurances. However, a further extension and upgrade of the
hydro-meteorological network is still required. together with more comrehensive studies of
eological processess and hazards (especially in the mountaneous regions)
There are regular shore protection works undertaken to protect people from floods and
mudflows. In 2009 for ex. almost 9 mln GEL was spent for such measures and 30 dangerous
shore sites were strengthened through constuction/rehabilitation of ground dams, stone or
concrete dikes. The climatic and geologic conditions of the country require that such activities
are continiued in the future on a regular basis.