SLOPES OF UTATSUUTATSU IS SURROUNDED BY MOUNDS ON THREE SIDESAND BORDERED BY SEA. WATER CANAL AND ELEVATEDHIGHWAY CUTS ACROSS THE SOUTHERN BORDER OF UTATSU. THIS ANALYSIS LOOKS AT THE SLOPES ON THE
NORTHERN SIDE, WHICH ACTED AS NATURAL BARRIERSTO THE 3.11 TSUNAMI.

DCB
A

E
F

SLOPE CLASSIFICATIONSHRINEHIDDEN RAMPSCHOOLSENTRYROAD

JR STATIONPARKING AREAvisual analysis of each slopes at eye levelFACDEBABC

DEFslope with shrine attop, elevated highwaycuts acrossdescription(cultural/builtenvironment)

slope by entry road toutatsuartificial mound forjr train. tunnel atground level

slope behind parking
lot

cut and filled slopeby two schools

slope behind residences, divides houses on
top from below

post-tsunami conditions

trees damaged by salt
water, uprooted trees

exposed top outersurface of tunnel

dead bamboo, uprooted
trees

not muchuprooted trees and bam- uprooted trees, hanging
items (unremoved)boo, hanging items

surfaces

concrete reinforcement,
concrete covered path,
piled stone at toe,

piled up stone, grassrocky surface,stone cliff

concrete wall,
grass pathces

trees, exposed bedrock, salt water damage tosoil color is different cedar trees, damaged
house next to stairs

slope/landform (degrees)

50

40

50-80

50-90

60-70

30 (stairs)

approximate height

8-10m

10-12m

18-22mvaries15m

30m

cut/fillcut on road side

artificial

cut at toe, piledstone

cut at two levels for
ramp, concrete wall

accessibility

thru concrete covered
narrow slope path

ramp up to station

not accessible

ramp (cars + people)

cut at toe, filled with toe/middle cut at nw
side for road, sliced
concrete wallat sw side for highway
hidden private ramp bestairs to shrine
hind destroyed houses

slight erosion on sides
exposed bedrock

exposed stone inner
fill, missing grass
patches

erosion +++5m up from ground all
erodedno visible erosion

cedar trees, shrubs

grass

trees, bamboo, grass

grass

soil/erosion

vegetation(shrub,tree,ground cover)slope section

near groundnear groundthin trees, bamboo,
small shrubs

dense cedar trees

SLOPE A - cedar tree mound by entry road to utatsu

TOE - MIDDLESLOPE CUT ON
ROAD SIDE.
FILLED WITH
CONCRETE REINFORCEMENTAtransectsection

8-10M

CONCRETE COVEREDPATH UPTO HOUSEON TOP OF HILL

slope by entry road to utatsu
EXPOSED BEDROCKtrees damaged by salt water, uprooted trees

SHRUBSTREES DAMAGED BY TSUNAMI-SALT WATER SATURATION

concrete reinforcement,concrete
covered path, piled stone at toe,

TSUNAMI EROSION-EXPOSED TREE ROOTS

50 degrees slope
50 DEGREES

8-10m
cut on road side
PILED ROCKS AT
GROUND-TOE

access thru concrete coverednarrow slope pathslight erosion on sides
exposed bedrock
vegetation: cedar trees, shrubs

TRANSECT SECTION

concretereinforcement

ELEVATEDHIGHWAY

8-10m

SLOPE A50

piled up rocks
at slope toe

WATERCANALDETAILED SECTION THRU SLOPE A

SLOPE A
A-2
TEN
EET CEMR
NC OR
CO INF
REA-1

concrete pathremaining concrete
foundation of housemoss covered soil

fence

concrete covered path
exposed bedrock

concrete reinforcement
concrete covered path
piled-up stone

detail a-1

detail a-2@ concrete reinforcement wall

@ exposed rock/concrete path

SLOPE B - ARTIFICIAL MOUND / JR LINE TRAIN TRACK**engineered slope

B

RAMP UP TO
STATION
TUNNEL
artificial mound for jr train.
tunnel at ground level

JR STATION

exposed top outer surface oftunnel

10-12M
TUNNEL

piled up stone, grass
40 DEGREES
SLOPE

40 degrees slope
10-12martificial

ramp up to station
exposed stone inner fill,
missing grass patches
grassengineeredslope

4010-12M

JR UTATSU
STATIONEXPOSED PILEDUP STONESLOPE C - BEHIND PARKING LOT

18-22m heightCctseantrnioct

sewhere: slope behind parking lot
post tsunami condition: dead bamboo, uprooted trees
surface: rocky surface, stone cliff
exposed roots
large amount oferosion up to5m above ground50-80 degrees slope
18-22mcut at toe, piled stone

exposed roots
large amount of erosion
up to 5m above ground50+ degree
slope

not accessible
erosion +++5m up from ground all eroded
piled stone

vegetation - trees, bamboo, grass

TRAN
TRAN
ANSE
NSESECCTT S
ECTIONECTIOTIONNTRANSECTSECTIONelevated
highway

18-22mpiled up rocks

water
50-80

barrierwall

hospitalremnants

slope cSLOPE D - SCHOOL GROUNDSD

cut and filled slope by twoschools
not much visible damage
ramp roadfor vehicles

surface: concrete wall, grass
pathces50-90 degrees slope
concrete reinforcement

height varies
cut at two levels for ramp, concrete wall
ramp (cars + people)
no visible erosion
vvegetation: grass

concretewall

50 -90grass patches

SLOPE E - BEHIND RESIDENCES

eslope behind residences, divides
houses on top from below

15m height

uprooted trees and bamboo,
hanging items
thin trees, bamboo, shrubs

trees, exposed bedrock, soilcolor is different

hidden private ramp behind
destroyed houses

60-70 degrees slope
15m approximate height
cut at toe, filled with concretewallhidden private ramp behind
destroyed houses
concrete wall
erosion near ground60-70 degrees slope
vegetation: thin trees, bamboo,
small shrubs

15m
concrete wall

60 -70

exposed bedrock
due to erosion

SLOPE F - SHRINE

fslope with shrine at top, elevatedhighway cuts acrossuprooted trees, hanging
items (unremoved)salt water damage to cedar trees,
damaged house next to stairs
30 degrees (stairs)
30m height
toe/middle cut at nw side for road,sliced at sw side for highway

salt water
damage - redcedar trees
stair upto jinjastairs to shrine for accesserosion near groundvegetation: dense cedar trees
large amount oferosion at toemiddle of slope

30m

FROM LOOKING AT THE MAP ONLY:
NATURAL BARRIER - HOW HIGH ARE
THE SLOPES?

SLOPES OF UTATSU FINDINGS FROM THE VISIT
Prior to visiting Utatsu, students studied the aerial photos and topographic maps of the site. some of thequestions we had were the effectiveness of the naturalbarriers of slopes against tsunami, incurred damage on
the slopes, and also whether the slopes were accessible
for residents as evacuation routes.

SLOPES B,D,E ARE ENGINNERED/DISTURBEDSLOPES. THE TSUNAMI DAMAGE MAP SUGGESTSTHAT ENGINEERED/DISTURBED SLOPES WERELESS EFFECTIVE IN LESSENING THE DAMAGE
FROM THE TSUNAMIBCDEFAPOST DISASTER DAMAGE MAP: HOW EFFECTIVE WERE THE ‘NATURAL BARRIERS’ AND ‘ENGINEERED BARRIERS’?

Actual visit to the site showed different reading ofthe slopes. almost all slopes were cut at toe up to midlevel, and filled with layered stone or concrete. thus,slopes were not accessible to be used as evacuationroutes. AN ALTERNATIVE USE OF THE ENGINEERED PORTION OFTHE SLOPES (CONCRETE EMBANKMENTS) COULD BE TO USE THE
THICKNESS OF THE WALLS AND OCCUPY THE THICKNESS BY CREATING RAMPED ACCESS, ETC.
However these slopes created a FORTRESS for the upper
grounds from tsunami inundation. Interesting finding fromthe site visit was that disturbed slopes were relatively
less effective in lessening the damage from the tsunami.
the damage map shows that the areas beyond slopes b,d,ande were also effected by tsunami. these were slopes thatwere either entirely engineered (slope B- train station
slope), or disturbed (slope D - cut and filled to create
ramped access, slope E- sliced to create road)