The 2011 East Japan Earthquake Bulletin of the Tohoku Geographical Association
http://tohokugeo.jp/disaster/disaster-e.html
13 April 2011, revised 29 March 2012

Regions in Affected Areas: regional divisions of the East Japan Earthquake
Disaster
Takehiko TAKANO, Professor, Tohoku Gakuin University
Email: tktk(a)izcc.tohoku-gakuin.ac.jp

A geographical outline of Eastern Honshu was presented, mainly concerning to the Pacific coast
suffered from severe tsunami disaster.

1. Outline of the affected region
The 2011

East JapanDisastergave

enormous damages especially in the Pacificcoast of east Honshu, the main land of Japan,
as shown in the beginning chapter.

In thischapter, the author will give a brief
description about its geography aiming to let
the region known for the world readers.
Fig.1 outlines the location of the affected
area

with

geomorphology,

Prefectural

boundary, major cities, and the arterialtransportation networks of Shinkansen andhighways in relation to Tokyo. Six northern
prefectures in the map constitute the Tohoku
Region and the southern seven prefectures
includingTokyoRegion.

Theconstitutethreetheheavily

Kanto
affected

prefectures of Iwate, Miyagi and Fukushima
are 150 - 500 km north of Tokyo and takes
about 2 hours on Shinkansen to Sendai, theregions dominant city.

The Fukushima

Daiichi Nuclear Power Station is 200 km
north of Tokyo and 100 km from Sendai.

Fig.1

Table 1 summarizes industries in five

Eastern Honshu and its sub-regions along
the Pacific coast1

severely affected prefectures along the Pacific coast.

The five prefectures’ shares to the national

total are: 11.6% of population, 12.0% of manufacturing shipment, 17.1% of agricultural shipment,
20.1% of marine fishery production, 17.8% of mariculture’s production.

Theses affected

prefectures have totally large outputs from agriculture, marine fishery, and mariculture relative tothe share of population.

But Ibaragi and Chiba Prefectures also have significant share ofmanufacturing shipment, because they have major industrial complexes in coastal areas.

Table 1

Population and industrial production of the five prefectures containing severely affected areasource : Population Census, Statistic Table of Manufacturing, Production Statistics for Fishery and Aquaculture

As shown in the previous chapter, the heavily damaged areas mostly located along the Pacificcoast which severely hit by huge tsunami.
evenly damaged.

It means that every region in the five prefectures got

But intensive shock of M 9 mega-earthquake, resulted interruption in traffic andelectric supply, and subsequent nuclear accident were commonly shared experiences among thefive prefectures.

It would therefore be proper view that every day lives of the people and every

industrial activities in almost whole area in five prefectures got significant damages at least in therelieving period after the disaster.

2. Sub-regions in the Pacific side of eastern Honshu
Nevertheless the intensity of damage was unprecedentedly extensive and enormous especiallyin the costal area affected by tsunami.

So the author will present commonly known sub-regions

related to the coastal area in eastern Honshu.
As indicated in Fig.1, the coastal area can commonly be divided into three regions, Sanriku
Coast, Sendai Bay Coast, Fukushima Hamadori Region, and East Kanto Coast based on natural,
historical and economic characteristics.

The tsunami affected the entire coast of these area.

1) Sanriku CoastSanriku Coast is called as “Rias” coast with indented coastline and limited flat lands which is2

similar to that of the Ria coast in
northwestern Spain.

It is typical in southof Miyako as shown in Fig.1 and enlarged
map of Fig.2 which shows such shapeclearler.
While remote from the main transport
networks, Sanriku Coast is suited to seaportwith calm inlet, of which offshore sea is richfishing ground.

Owing to such location,some major fishing ports developed as basesof the boat fishery from inshore to offshore.
The cities of Hachinohe, Miyako, Kamaishi,
Ofunato,Kesen-numa,

Shizugawa,Onagawa,Oshika,

Ishinomaki

anddeveloped as such base ports.
them,Hachinohe,AmongKesen-numa,

andIshnomaki are three biggest port cities notFig.2

only in Sanriku Coast, but also in Japan.
They

are

famousfortheircomplexes for fish processing.

Typical “Rias” type of coast in Sanriku Coast(from Kanamishi to Kesen-numa)

Entire area along the coast suffered from devastatedamages by tsuami on March 11, 2011.

industrialIn addition,aquaculture of oyster, scallop, “wakame” seaweeds, kelp, and silver salmon are thriving in inletsand inshore sea of Sanriku Coast.
At the same time, such shape of coastline inclines to amplify the intensity of tsunami, which
was caused by sudden thrust of the Pacific plate submerging at the Japan Trench running parallel toSanriku Coast.

Owing to such tectonic position, Sanriku Coast suffered from twice of severetsunami disasters after the Meiji Restoration in 1868.
Countermeasures against the expected tsunami had been in place, but the wave height this timeexceeded well beyond the supposition, and thus every fishing port and coastal village witnessed themost severe human losses and physical damages in Japan’s history (Fig.3).

Fig.3

Devastated port town of Onagawa (April,3 2011)3

Three-storied buildings even fell down.

2) Sendai Bay Coast
Sendai Bay Coast stretches along thesoutheastern shore of Miyagi Prefecture(Fig.1,4).

Based on the geomorphologic

feature, its coastal area can be divided
into several sub-sections; Ishinomaki
Plain, Matsushima Bay, Sendai Plain,
Natori Plain, and Watari Plain as shownin Fig.4.
Originally there stretched swamplandsin the coastal plains, most of which weredeveloped as agricultural lands mainly in
the Edo era (17-19 Century).

Amongthem, coastal area of Watari Plain has
developed as one of the most thriving
strawberry producer in Tohoku afterFig.4

Japan’s rapid economic growth in 1970’s.

Sendai Bay Coast

Coastal plains here were inundated by tsunami up to 4 or 5
km from shore line

In the same period, new industrial ports
were developed on the sand beaches nearcitiesofSendaiand

Ishinomaki

asdistribution bases for the commodities andindustrial resources.
Well known tourist spot of Matsuhima
Bay is located in the middle of coastal
plains,embracing

manysmallislands

thriving on aquaculture of oyster.

At thewestern end of Matsushima Bay, port city ofShiogama is located, which is one of thebiggest unloading port of fresh Tuna caught
by inshore fishery.
Huge tsunami reached up to 3 - 5 km
inland throughout Sendai Bay area but for
Matsushima Bay (Fig.5), affecting many
agricultural lands, coastal settlements andindustrial estates.
In addition, powerful earthquake gave

Fig.5

Depth of inundated tsunami flowwww.bousai.go.jp/jishin/chubou/higashinihon/7/sub8.pdf

4damages especially on the logistics hub of Tohoku Region
mainly situated in the coastal plain of Sendai and its
suburbs, affected entire distribution economy of TohokuRegion.
4）） Hamadori Coast
The Pacific coast of Fukushima Prefecture is locallycalled as “Hamadori”, consisting from the north of Soma,Futaba, and Iwaki regions (Fig.6).

Most of the populationand industries distribute along the national road 6 running
through lowlands sharply cut by Futaba active fault fromAbukuma Highlands in the west.

The lowlands are

consisted actually by terraced lands and fluvial plains
along small rivers flowing down to the Pacific Ocean.
Owing to narrow habitable area, density of population andindustrial activities is limited, except for Iwaki region
which was once major supplier of coal to main industrial
areas in Kanto and now has many kinds of industries taking
advantage of easy access.
As for the fishery, Harakama and Onahama havefishing base port for offshore fishery and Uketo is a local
fishing port.

A beautiful lagoon of Matsukawaura isknown as laver (“nori” in Japanese) cultivation.

Butoutput of marine products is far limited in comparison withSanriku Coast.

A straight coastline unsuitable for thedevelopment of big base ports should be one of historicalFig.6

factors for it.

Hamadori Coast★：nuclear power,☆thermal power

Distinctiveness of Hamadori’s industry is the locationof power generation plants, containing four thermal and two nuclear power stations.
are close in much of the coast and sea shore oriented industries did not develop.

Mountains

It resulted an

economic structure that depends on the power generation plant of Tokyo Electric Power Company(TEPCO) who found this region suitable.
The tsunami affected Fukushima Nuclear Power Plant under crisis is situated in Futaba region.
Most of Futaba region is within 30 km radius of Fukushima Daiichi Nuclear Power Station andunder evacuation control even now.

All of eight municipal authorities in Futaba moved theiroffices to other distant municipalities, and thus the whole regional society is under crisis.
5）） Coast of East Kanto
5From a geomorphologic viewpoint, thisarea can be divided into four sections(Fig.7); Joban Coast, Kashima-nada Coast(both in Ibaraki Prefecture), Kujukuri Coast,and South Boso Coast (both in ChibaPrefecture).

Among them, coasts of Joban

and South Boso have ragged shoreline withsome fishing and industrial ports.

Coastsof Kashima-nada and Kujukuri have straightshaped sand beaches, but Kashima-nada
Coast is interrupted by Kashima Industrial
Complex developed since 1960’s where
somemajor

plantsmaterials located.

makingindustrial

At the location where

Kashima-nada and Kujukuri Coast meets,
Chosi City developed as one of Japan’smajor fishing ports.
In Joban Coast, many ports were affected
Fig.7

by tsunami, but damage was rather limited
to port area.

In Kujukiri Coast, tsunami

East Kanto and liquefaction

http://www.ktr.mlit.go.jp/ktr_content/content/000043569.

pdf(modified by the author)rose up to 7.6m in maximum at Iioka town
where 13 persons were killed more than 700 houses were destroyed.
In East Kanto Region, liquefaction appeared vastly in almost every reclaimed land not only incoastal area but also in former swamplands inland (Fig.9).

About 27,000 houses got suchdamages as ground subsidence and house leaning by the liquefaction in Kanto Region.★1

In

Kashima Industrial Complex, many factories were interrupted their operations by liquefaction as
well as inundation.

Thus, liquefaction caused by the mega-earthquake of 2011 was believed as

the largest one in world history of earthquake disaster.★2

3. Regional differentiation appeared in recent statistics on population and industry
Finally some statistical maps will be shown in order for the readers to grasp the local
differences between the coastal and other areas more clearly based on what was described above.
Fig.8 shows a distribution of population with its change ratio (2010), cultivated land (2009), andshipment value of manufacturing industry (2008) by municipality in five prefectures.

Population

distribution shows that coastal area in Hamadori and Sanriku are relatively less populated andindustrialized than Kanto and arterial inland region where Shinkansen and highway run.
6

Especially rapid decrease of population and manufacturing industries and aging of population havecontinued since 1990’s, that is the so-called “lost decade” of Japan.

Fig. 8Distribution of population with ratio of the aged (2005), cultivated land (2009), and shipment valueof manufacturing industry (2008) by municipality in the Pacific side five prefectures

4. Prospect
In this chapter, a geographical outline of Eastern Honshu was presented, mainly concerning to
the Pacific coast suffered from severe tsunami disaster.

Many of the affected regions have faced

severe situation even now with the delay of redevelopment measures especially in Sanriku Coastand unprecedented hard situation of radioactive pollution around the devastated nuclear power
plant.

Nevertheless, they must still play a important role in marine fishery of which products canmake the variety of Japanese cuisine.

Long time supports will be needed until their industries andeveryday lives can recover.
7

Reference★1：Number of damaged houses is cited from Yomiuri Online, Jan. 12, 2012.

Detailed reports of the liquefaction inKanto Region are downloadable from following sites; http://www.ishikawa-geo.or.jp/sitemap/img/higashinihon.pdf,
http://www.ktr.mlit.go.jp/ktr_content/content/000043569.pdf.
★2：Nippon Keizai Shinbun, May 1, 20118