Historical Disaster Profile of Nepal
(Based on the NSET Disaster Observatory database)
Map 1: Nepal general location and Regions (Far Western, Mid Western, Western, Central and Eastern)
Country Background
Nepal is a landlocked country lying between India and China, with a total area of 147,181 square
kilometers. It is divided in to three ecological regions: the ‘Terai’ in the south, the ‘Hills’ in the middle
and ‘Mountains’ in the north. The Terai region is low-lying and highly prone to hydrological disasters and
similarly the hills and mountain areas are highly vulnerable to landslides and earthquakes.
Nepal has an estimated population of 29 million (CIA fact book, 2008). The majority of the population is
concentrated in the rural areas and consequently the density of rural population is relatively high at 686
people per square kilometer, which exceeds that of the most low-income countries (World Bank, 2002)
From geographic perspective Nepal is located in the middle portion of the Hindu-Kush Himalayan
Region. Nepal displays extreme variations in natural environment ranging from tropical plain to alpine
heights with decreasing elevations from north to south. It has a unique altitudinal variation from 60
meters from mean sea level at Jhapa in the south to 8,848 meters at Mt. Everest in the north – big
variation within a short horizontal distance of only 90 to 120 km. Due to the east-west orientation of the
mountain ranges, the country is traditionally classified into three major geographic regions, notably,
Mountain, Hill, and Terai regions.
The Himalaya is said to be the most active and fragile mountain range in the world as is still rising and its
rocks are under constant stress as the northward –moving Indian Plate pushes against the more stable
Tibetan block. This pressure forces the Himalaya to rise and move horizontally southward along major
thrusts. The active nature of the range is also manifested by frequent earthquakes. Moreover the
inherently weak geological characteristics of the rocks make the Himalaya very fragile. Triggering factors
such as rainfall and earthquakes make the mountains highly vulnerable to landslides and other mass
moving processes. (GAR Report)
In summary one can say that a combination of rough topography, steep slopes, active seismic zone and
intense impact of monsoon rain has made this fragile environment vulnerable to hazards and disasters.
Nepal is one of the most disaster-prone countries in the world and has experienced several natural
catastrophes causing high economic and human losses. Heavy rain and storms can cause severe
flooding, or trigger landslides that have an enormous effect on property, structures and lives. On the
other hand, during the dry season, Nepal is prone to fire and wildfire. In the mountain region, most
common disasters are avalanches and snowstorms causing physical damage and human losses.
Moreover, Nepal is prone to other disastrous events like epidemics and pollution. Every year a
significant proportion of GDP is lost because of natural disasters. (GAR Report)
For the effects of the Disaster database, information is associated with the corresponding administrative
units, namely Regions (Central, Eastern, Western, Mid-Western and Far Western), 75 Districts and 3982
Villages (VDC).
A preliminary automated Country Profile for Nepal can be found as GRIP’s website at
http://www.gripweb.org/grip.php?ido=39215212&lang=eng&countrycode=np.
This automated profile and the contents of this detailed profile are based on disaster loss data for more
than 37 years (since 1971). The preliminary profile presents basic charts, maps and tables showing the
composition of events causing mortality and impact to the housing sector, the geographic distribution of
the losses (to identify high-risk areas), and the trends in risk change during the last 37 years.
Note: 2008 Floods are NOT included yet in this database version.
The following sections contain quick interpretations and some additional information to these charts,
maps and tables.
Composition of Disasters:
a) Classification of Events by Frequency (number of Records
- proxy for frequency):
Epidemic and fires are the most reported events.
However, the database reveals that floods and landslides
are the most frequent reports among the non-anthropic
event types.
b) Classification of Events by Mortality
Epidemics is the event type reporting the highest number of casualties. Landslides and floods
are the main contributors to mortality in the country, followed closely by fires and earthquakes.
TO CONFIRM: Despite Floods arguably are a public health problem it is interesting to see a very
high degree of correlation between floods and immediately occurring episodes of epidemics.
We found more than 500 records of
epidemics apparently related to floods. The
procedure sought epidemics occurring
within 30 days of the reporting of the flood
in the same areas. See temporal analysis for
a chart showing this fact. If this correlation
is confirmed the impact of floods could be
of a much higher magnitude.
As interesting facts thunderstorm seem to take a high toll (624 killed), same as forest fires (416).
c) Classification of Events by Housing sector
damage/destruction
Here we find a slightly different distribution of
the impact as earthquake damage is much
clear (about 30% of total damage), but still
floods are the most contributing factor.
Initial conclusions:
Floods and Landslides are the types of events that should be prioritized in the Risk Assessment work,
followed by Earthquakes, which play also an important role as also do Fires.
Spatial Distribution of damages per hazard type:
Floods
There are more than 6,000 rivers and streams in Nepal. Each year, flood causes immense
damage to agricultural land, crops, human settlements and other physical properties. In July of
1993, Nepal experienced a devastating flood in the Terai region, which took the life of 1,289
people and affected 575,000 people. In 1998, flood affected again about half million inhabitants
and caused the total loss of about 2 billion Nepal rupees(approximately $US29 million).
Since 1971 there is a record of significant loss of lives and livelihoods due to floods on every
single year.
According to a report from The International Centre for Integrated Mountain Development
(ICIMOD), glacier lakes in the mountains are becoming very large due to melting of glaciers.
There are more than 20 potentially dangerous lakes in Nepal that can affect tens of thousands
of people severely in the mountains and down-stream areas.
The recent (2008) Saptakoshi river floods and landslides in 28 districts of the country affected
more than 300,000 people (data not reflected in the current DesInventar database).
A very interesting fact is that mortality and damages to housing and infrastructure seem to be
spatially distributed in different ways. While mortality is concentrated in the foothills (‘Hills’)
and mountains of the Himalayas (probably these floods are associated to Flash Flood events) the
damages to housing, and (extrapolating) most of the livelihood assets are concentrated in the
more flat area neighboring India.
In these maps – a detail of overlaying the terrain model and losses in the housing sector – can be clearly
seen that most of the damage has happened in the flatter areas(‘Terai’). There is a second tier of
damage in the Hills and up in the Mountains there’s less damage reported. This contrasts with the next
map overlay (Mortality), where the flat areas show less impact. Some areas (right corners of the country
show both types of damage).
20 Highest Mortality districts
20 Highest Damage/Destruction to Housing
region
district
Deaths
region
district
Central Region
Sarlahi
710
Central Region
Sarlahi
Housing
28415
Central Region
Makwanpur
262
Central Region
Rautahat
17965
Central Region
Sindhuli
225
Mid-Western Region
Bardiya
15946
Central Region
Chitawan
204
Eastern Region
Sunsari
12414
Central Region
Rautahat
152
Eastern Region
Saptari
12392
Eastern Region
Morang
89
Central Region
Mahotari
11126
Western Region
Baglung
79
Central Region
Dhanusa
10581
Western Region
Rupandehi
77
Eastern Region
Siraha
6143
Central Region
Lalitpur
67
Central Region
Chitawan
5153
Central Region
Kavre
62
Western Region
Nawalparasi
4942
Western Region
Syangja
61
Central Region
Makwanpur
4448
Central Region
Dolakha
44
Western Region
Kapilbastu
3554
Western Region
Tanahu
43
Central Region
Sindhuli
2985
Eastern Region
Udayapur
40
Eastern Region
Morang
2974
Central Region
Nuwakot
36
Eastern Region
Jhapa
2098
Central Region
Dhading
35
Eastern Region
Udayapur
1349
Eastern Region
Jhapa
35
Central Region
Parsa
1111
Central Region
Kathmandu
32
Central Region
Ramechhap
947
Central Region
Sindhupalchoke
31
Far Western Region
Kanchanpur
895
Mid-Western
Region
Dang
31
Mid-Western Region
Dang
793
Landslides
According to the disaster database, Landslides are the cause of 4,763 deaths in the country.
Being as secondary hazard, a quick analysis of the data reveals that 1883 of 2185 records of
landslide records (over 86%) are explicitly associated with heavy precipitation in the database,
while only one event is associated to earthquakes. This is an important factor to take into
account when doing the Eartquake risk assessment.
A look at the spatial distribution of landslides tells that distribution of mortality and livelihood
assets are similar, located over the mountain areas. A second important fact is that as landslide
are highly localized only a fraction of the records (and impact) spans over more than one VCD
(lowest level of geo-reference on the database).
About 36% of the impact of landslides (1621 casualties; 7,004 houses destroyed, …) is
concentrated on the Central Region, also the most populated area, followed by the Western and
Eastern regions:
region
Central Region
Eastern Region
Far Western Region
Mid-Western Region
Western Region
TOTAL
DataCards
750
410
170
238
617
2185
Deaths
1419
808
329
300
1131
3987
% of Total
36%
20%
8%
8%
28%
A more resolution study of the spatial distribution of historical losses due to landslides should be
done outside of the scope of this profile; this can provide very valuable information given the
highly localized nature of landslides. As example of the possible output the following map shows
the higher resolution map for the Central Region, where two potentially more prone clusters of
VDC’s can be clearly identified in addition to the Kathmandu valley. Similar clusters can be
identified too in Western and Eastern regions. Specific VDC’s with a history of landslides can also
be identified and prioritized for work in RA from this detailed info.
Earthquakes
The entire country lies in a high earthquake hazard area as previously said, and thus the entire
country is prone to earthquake hazards. The historical losses for recorded for the last 37 years
show that Far Western and Eastern Regions as those having the highest levels of accumulated
losses having faced the occurrence of a significant number of earthquakes during the period.
Both the frequency of earthquake occurrence and the accumulated losses are higher in numbers
in Far Western districts than in districts of Eastern region.
Districts in western region (Baitadi, Bajhang, Darchula) were severely affected by 1980
earthquake in terms of casualties and damage in property especially buildings. Similarly, districts
of eastern region (Dhankura, Ilam, Jhapa, Khotang, Morang, Panchthar, Sankhuwasabha, Saptari,
Sindhuli, Sunsari, Tehrathum, Udayapur) were severely affected by 1988 earthquake. (GAR
Report)
Maps below clearly shows the distribution pattern of casualties caused by earthquakes during
1971 – 2007.
OTHER HAZARDS:
While Epidemic and Fire are probably not being the subject of a future detailed National Risk
Assessment it is worthwhile a quick look at them:
Epidemics:
Being the event with a largest death toll it may be of interest to target it as part of the DRR initiative,
especially if the cause-effect relation between floods and epidemic episodes can be strongly established,
which is outside of the scope of this profile.
In addition to some statistical analysis that suggests this relation may be valid, the spatial distribution of
floods and epidemics coincide in the flat areas of the country, where this correlation may be stronger,
and floods are frequently slow onset disasters which usually trigger epidemics. The small map below
show losses of housing sector due to floods – as stated above as a proxy of loss of assets and inundation
of large areas as opposed to flash flood events in the mountain areas which are much higher in
mortality.
Distribution of deaths due to Epidemics
Distribution of housing losses due to floods