The 2011 East Japan Earthquake Bulletin of the Tohoku Geographical Association
December, 29, 2011

Outline of the highly polluted evacuation areas by the severe accidentof the Fukushima Daiichi Nuclear Power Station
Takehiko TAKANO（Tohoku Gakuin University）

1. Outline of the accident and the purpose of report
Fukushima Daiichi Nuclear Power Station is locatedon the Pacific shore about 200 km north of Tokyo, andabout 100 km south of Sendai (Fig.1).

Three nuclear

reactors among six in total were working when the megaearthquake occurredat 14:46, March

11.

The

emergency shut-down system started at once, and threereactors stopped safely.

But huge tsunami with theheight of 13～15m struck at whole plant about four
minutes later, which stopped all of emergent power
supplies, resulting all of the cooling facilities for every
nuclear reactors were lost.

Such accidental conditions

caused a series of vents and hydrogen explosions foreach of three power plants from 12th to 15th, March,each of which time huge amount of the highly
concentrated radioactive materials exhausted in the airand dispersed broadly in the environment.

Much ofradioactive materials were also flew out to the sea.

Fig. 1 Location of Fukushima Daiichi
Nuclear Power Station

Through this serious event, total amount of radioactive materials dispersed to the air wasestimated to reach more than 37×1012 Bq，and the level of nuclear accident was rated as theworst of 7th in terms of International Nuclear Event Scale.

Most of the 80,000 residents

inside of 20～30 km circular area from the power station were obliged to evacuate from theirhometown before grasping the damage of earthquake and tsunami.

Their situation as evacuee

has not changed yet for nine months. It is feared that the significant amount of people could
never return to home in their lifetime.
The purpose of this brief report is to describe the regional characteristics of highly
contaminated evacuation areas around the Fukushima Daiichi Nuclear Power Station, that is
how the region is/was like in term of the industrial basis.

The author will also report on thedistribution of lower level of pollution observed by accumulation of cesium, which suggests thebehavior of the air flow when the accidents took place.
12．Designation of the evacuation and controlled area
In this unprecedented situation, nationalgovernment

pronounced a “no entry”

evacuation directive to the area within 20
km sphere from the nuclear power station(Fig.2)onMarch12,andthe“staying-indoor” control implemented to
the 20～30 km zone was terminatedtakenout on March 15.
In

addition,

observation

ofaprogress

theofactual

contaminationofradioactive materials clarified that thehigh-concentrationarea

whereyearly

accumulative dose might reach 20mSv had
spread northwestward (Fig.2).

It wasconsidered to mainly be conveyed by thewind at the time of the hydrogen explosion
on the morning of March 15 and theinfluence of rain after that.
nationalgovernment

Fig. 2 Yearly accumulative dose (mSv) estimated by
the real value observed from 11, March to 21, April

On April 21,

designated(http://www.mext.go.jp)"plannedevacuation area" which urge the residents toevacuate in one month for these area, i.e.,
Iitate-mura, Katsurao-mura, Tsushima district ofNamie-machi,

Yamakiya

districtof

Kawamata-machi, and southwestern area of
Minamisoma city (Fig.2 and 3).
At the same time, 20～30km zonal area underthe “staying-indoor” control was designated as“ready to evacuate area” in possible emergent
case, where children, pregnant women, andhandicapped person were needed to evacuate.
Furthermore,

severalspotsofhighlycontamination where yearly accumulative dose
was estimated to reach 20mSv were discovered

Fig. 3designated areas

outside those designated areas, then the measure of “evacuation recommended” areas were2designated in such places since June 30.

The number of the areas reached to 12 settlements,

most of which were located in the northwestern and northeastern parts along the 20mSv line
shown in Fig 2 and 3, with 282 households in total by November 26.

3. Regional characteristics of the designated evacuation areas
1）Physical Setting
Geomorphology of thedesignated

areas

to

evacuate and ready toevacuateistypically

shown in Fig.4.
areascanbeThe
dividedclearly into such threegeomorphologic parts as
below from east to west
Fig. 4along Pacific shore:

typical geomorphology of the designated areai) coastal area called as “Hamadori” consisting of such two sub parts as the table lands withthe altitude of 20～50m and the narrow plains along small rivers flowing down cutting the tablelands to the Pacific Ocean,ii) steeply sloped area along the Futaba fault being cut by some deep valleys,iii)

Abukuma

Highlandwith

thealtitude of about 500m.
Many settlements in the coastal plains
were flooded out by the tsunami after themega-quakeofMarch,11.

By

the

meteorological observation when

thehydrogen explosion happened on March
15, most of the radioactive materials wasestimated to disperse northwestward
along one of the deep valleys between thecoastal area and the Abukuma Highland.
2）Population
Population

distributioninthemunicipalities to which the designatedareas belong is shown in Fig.5.

Many of3Fig.5

distribution of population（2005）

the residents in this areas live in the coastal area,
and the population density is rather low in thesloped area and Abukuma Highland.

Table 1 estimated population of each
evacuation zone

The numberof population and households for each designatedzone and area are shown in Table 1.
Entire population in the “no-entry” 20km zone andpopulation

households

20 km zone

72,891

23,20430 km zone

133,053

43,078plannedevacuation area

11,2293,033

the most of population in “planned evacuation area” were obliged to evacuate to another places.
The situation in which up to 84,000 persons are obliged accidentally to evacuate would be thesituation Japan has never experienced in the past. But a fact that most of population resides
in the narrow corridor both side of which are the sea and the thinly inhabited mountainous landas shown in Fig.5 could not had been the worst situation.
3）Industries
In the designated areas shown in Fig.3, most of the economic activities stopped, and when
they can restart is unclear even after nine months passed.

Table 2 shows the census data forthe manufacturing and commercial industries by municipal district shown in Fig.3.
shadowed districts are containing heavier polluted areas by radioactive materials.

TheAccording

to the table, about 2,400 establishments, 20,000 persons’ business opportunities, and 402 billion
yen of industrial outputs was lost for a year.

Distribution of the commercial industries is like as the population distribution shown in Fig.5,
that is, regional center city of Haramachi is the biggest and sub-centers of Namie and Tomioka
are the second and third biggest commercial places. As for the manufacturing industry are4

located rather evenly in the coastal area.

Such industries are few in Abukuma Highland area.

As for the type of manufacturing industry, Haramachi’s data in 2004 manufacturing census isonly usable.

According it, “electronic components”, “machinery instrument”, “rubbercommodity”, and “clothes and textiles” are the four major manufacturing sections.

Generallyspeaking, these sections are the “labor-intensive” types.
Although this area is not prosperous industrial region in Japan, the industries shown in
Table 2 provided important employment opportunities for the residents.

Long term

evacuation and stoppage of industrial operation are unavoidable, which will be one of the
difficulties for recovery of this area.
4）Agriculture, Livestock farming, Forestry
Radioactivity materials dispersed from the nuclear power station polluted the farmlands,
forests, rivers and sea, which gave serious damage to the primary industries in this area.
Because the detailed facts will be described in the following section, the authors will give here
an outline of the primary industries in the designated areas.

Some basic statistics of agricultural, livestock and forestry by the municipal district are
shown in Table 3.

From the table, we can grasp firstly the fact that about 13,000 farmers

produced the value of 27 billion yen from 18,000 ha of arable lands. Especially, Namie town
and Iitate village which belong to the densely polluted zone are main agricultural areas in theregion.

In the second, we can know that many of cattle raising and forestry activities wereoperating in Abukuma Highland.
5Fig 6 shows the composition of major
crops planted by statistical unit named“shuraku” that is a kind of agriculturalcommunity. Rice is the major crop forthe most part of the region especially inthe coastal area.

“Industrial crops”

including mainly tobacco in this case areprominent in the western edge of theregion.
intheVegetables are also major crops
northwesternpart.

The

communities one of whose major crops is
the “millet” including mainly buckwheatin this case are shown in some parts.
Average acreage of the cultivated landper a farmer is 1.46 ha in this region,
which is rather larger than Japan’saverage.

But the crops with higher

productivity such as garden products orgreenhouse crops are very limited.

Inaddition, feeding crops for domestic
livestock are contained to the average
acreage.

Soto

speak

generally,

Fig.6

agriculture in this region cannot be saidarea (ha) and composition of major crops plantedby agricultural community（2005）

as intensive one.
On the other hand, there contains a village famous for cattle raising such as Iitate, whose
beef is well known brand in Fukushima Prefecture.

“Shiitake” mushroom farming belonged

statistically to the forestry industry is widely operating mountainous area especially in
Abukuma Highland.

In addition, nurturing forestry and timber production are well-known

local industry in Miyakoji village.
5）Fishery
Although this region faces Pacific Ocean, fishery industries cannot be said so thriving as
Sanriku Coast which suffered serious damages by tsunami.

According to 2008 Fishery Census,

166 fishery workers and 108 fishing boats were registered in this region.

Most of them belongs

to Uketo fishing port in Namie, at the location about 6 km north of the nuclear power station.
Main types of fishery are the drawing net, gilling net and rod fishing by small boat mainly lessthan 5 ton.

Main catches are such small fishes as sand lance or young sardine and stable
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flatfishes including flounder.
Fukushima Prefecture prohibited the fishery operations for at least one year in fear of thediffusion of radioactive contamination to the sea. Actually the periodic sampling of marine
products indicated that the contamination of marine creatures was tending to increase withtime, which will be shown in more detail in the following section.
In the rivers flowing from Abukuma Highland down to Pacific Ocean, many salmon are
coming upstream every autumn.

In 30km zone from Fukushima Daiichi Nuclear Power

Station, River Fishery Cooperatives are organized in five rivers, and manage the artificial
hatching and stocking activities. Especially the number of salmon catches in Kido river in
Naraha town was one of the most thriving salmon rivers in Honshu island. Every incubation
facilities in these rivers were entirely destroyed by the earthquake and tsunami, and four rivers
among five are located in “no-entry” 20km zone from the nuclear power station.

4．Diffusion of the lower level of polluted area
Theradioactive

materialspreadwidely beyond the evacuation areas.
Japan’s Ministry of Education, Culture,
Sports,Sciencepublished

andradiation

Technology
doseandaccumulation of Cesium several times.
Fig.7 shows the accumulation amountof Cesium 134 and 137 in land surface
estimated by November 5. According
to it, the way of the diffusion ofradioactive materials is considered toreflect wind direction and rain whenthe explosion happened and after, andgeomorphologic features. That is, theconcentrated

radioactivematerials

were at first carried northwestward
fromthepower

plantacrossAbukuma Highland to Fukushima
Basin,

andthey

wereturned

Fig.7

southward along the Abukuma river
basin where lower level of pollution

Accumulation of Cs-134 and Cs-137 in land
surface Estimated by November 5(http://radioactivity.mext.go.jp/ja/1910/2011/12/1910_1216.pdf）

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came.

lower level of pollution went then to the northern Kanto district and partly to justeastern neighbors of Tokyo.
In contrast to it, such place as western half of Fukushima Prefecture (Aizu region) andnorthern neighboring area in Miyagi Prefecture escaped from the flow of contaminated air,resulting in the lower level of accumulation in spited of their nearer distance.
A kind of “barrier effect” of the geomorphology can be observed in northern part of Kanto areaand boundary area between Miyagi and Iwate prefectures.

A flow of the contaminated air

seemed to be interrupted here by the mountain ranges and fall to the ground with the rain.

Inaddition, it was a likely situation that the dividing range of Ou mountains in the middle of
Fukushima Prefecture interrupted the air flow into Aizu region.

5．Prospects
Though the situation of evacuated people has not changed even nine months after theaccident, the efforts to restoration of the evacuated areas has been continued.

It is necessary

to eliminate the radioactive materials from the contaminated areas. National government
decided that elimination activities in the areas where accumulative dose could reach more than
1 mSv were responsible for national budget, and pronounced the those areas which contained
102 municipalities in eight prefectures.

But the first decision of stock yard for the polluted

materials bearing radioactivity has became a problem hard to make consensus in theinhabitants.
December, 16, 2011, national government stated three broken nuclear reactors reached safe
and stable situation with enough low temperature, and the countermeasures for the accident
shifted to the next stage containing the long time effort to abolish the broken reactors.

Andneedless to say the unprecedented difficult process will be needed to restore the everyday livesof the inhabitants and their communities.

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