>> Heather: WELCOME BACK TO
WICHITA STATE UNIVERSITY'S
LIFELONG LEARNING PROGRAM.
I'M HEATHER MERCHANT AND THIS IS
THE GEOLOGY OF NATURAL
DISASTERS.
BEFORE WE GET INTO WEEK 3,
LANDSLIDES AND FLOODS, WE HAVE A
COUPLE HOUSEKEEPING THINGS TO
MENTION.
AT THE END OF THE LECTURE, IF
ANYONE HAS A QUESTION, YOU CAN
PLEASE WALK UP HERE TO THE
MICROPHONE THAT'S ON MY RIGHT,
IT WOULD BE YOUR LEFT, AND STAND
ON THE BLUE X THAT'S ON THE
FLOOR AND SPEAK INTO THE
MICROPHONE.
BUT WE ASK THAT YOU PLEASE
REFRAIN FROM TOUCHING THE
MICROPHONE.
ABOUT HALFWAY THROUGH, WE'RE
GOING TO TAKE A 10-MINUTE
BATHROOM BREAK.
AND THE REST ROOMS ARE OUT THAT
DOOR.
THE LADIES' ROOM TO YOUR RIGHT,
THE GENTLEMEN'S ROOM IS TO YOUR
LEFT.
AND IF YOU'RE IN THE ONLINE
PORTION, IF YOU HAVE A QUESTION,
PLEASE E-MAIL IT IN.
AND NOW I'LL READ WSU'S POLICY
ON FACE COVERINGS.
STUDENTS, FACULTY, STAFF, AND
VISITORS MUST WEAR FACE
COVERINGS OVER THEIR MOUTHS AND
NOSES WHILE ON ALL WICHITA STATE
UNIVERSITY CAMPUSES, IN ALL
HALLWAYS, PUBLIC SPACES,
CLASSROOMS AND OTHER COMMON
AREAS OF CAMPUS BUILDINGS.
SO A CHANGE THIS WEEK IS I WILL
BE WEARING A MASK AS WELL.
SO IT CAN MAKE IT A LITTLE MORE
DIFFICULT TO HEAR ME, SO IF
ANYONE CAN'T HEAR OR UNDERSTAND
ME, PLEASE JUST RAISE YOUR HAND
AND I'LL TRY TO SPEAK A LITTLE
LOUDER.
OKAY.
AS I SAID BEFORE, WE'RE ALREADY
UP TO WEEK 3.
AND WE'RE GOING TO COVER
LANDSLIDES AND FLOODS TODAY.
SO THE TOPICS WE'LL BE COVERING
UNDER LANDSLIDES, WE'RE GOING TO
LOOK AT THE CLASSIFICATION OF
LANDSLIDES, WHAT FACTORS CONTROL
LANDSLIDES, WHAT TYPES THERE
ARE.
UNDERWATER LANDSLIDES.
REDUCING LOSSES, CONTROL, AND
STABILIZATION.
AND THEN WE'LL LOOK AT SOME
HISTORIC LANDSLIDES AND WATCH A
FEW VIDEOS OF THOSE.
FOR FLOODS, WE'RE GOING TO LOOK
AT AND LEARN THE HYDROLOGIC
CYCLE, RUNNING WATER, DRAINAGE
BASINS, THE CAUSES OF FLOODS,
SIZE AND FREQUENCY OF FLOODS,
MITIGATION, HISTORIC FLOODS, AND
THEN L SOP FLOODS THAT -- AND
THEN SOME FLOODS THAT WERE VERY
SPECIFIC TO US IN KANSAS AND
WICHITA.
SO THE TERM LANDSLIDE IS A VERY
GENERIC TERM.
IT'S OVERARCHING FOR MANY
DIFFERENT EVENTS.
IT'S NOT JUST ONE THING.
IT REFERS TO THE DOWNWARD
MOVEMENT OF A MATERIAL CAUSED BY
GRAVITY.
IN GEOLOGY, WE DON'T NECESSARILY
USE THE TERM LANDSLIDE.
WE GENERALLY USE THE TERM MASS
PEACING.
SORT OF A SCARY SOUNDING TERM.
AND IT'S ONE THAT YOU DON'T HEAR
THAT OFTEN.
BUT WHEN GEOLOGY IS TAUGHT, ALL
FORMS OF LANDSLIDES ARE
CONSIDERED MASS WASTING EVENTS.
SOMETIMES YOU WILL ALSO HEAR THE
TERM MASS MOVEMENT OR SLOPE
FAILURE.
BUT FOR THIS CLASS, WE'RE GOING
TO CONTINUE JUST CALLING THEM
LANDSLIDES.
SO LANDSLIDES ARE CLASSIFIED IN
THREE DIFFERENT WAYS.
BY THE RATE OF THEIR MOVEMENT,
THEY CAN BE VERY, VERY SLOW,
JUST CREEPING ALONG AND YOU
DON'T EVEN KNOW THAT THEY'RE
HAPPENING UNLESS YOU'RE TAKING
MEASUREMENTS.
OR THEY CAN BE SO FAST, THEY'RE
ALMOST INSTANTANEOUS, AS IN AN
AVALANCHE.
AND THEN THERE'S DIFFERENT TYPES
OF MATERIALS.
THERE'S MUD FLOWS.
THERE'S ROCKFALLS.
YOU CAN HAVE SOIL, SILT, CLAIRE,
IT CAN BE WET, IT CAN BE DRY.
SO WE'RE GOING TO LOOK AT THOSE.
AND THEN THERE'S TYPES OF
MOVEMENT, THINGS MOVE IN
DIFFERENT WAYS.
THEY CAN SLIDE, THEY CAN FLOW,
THEY CAN FALL.
AND THE DIAGRAM ON YOUR RIGHT
SHOWS THE BASIC PARTS OF A
LANDSLIDE.
SO YOU DON'T NEED TO KNOW THOSE,
BUT THEY'RE THERE FOR YOUR
REFERENCE LATER ON WHEN YOU LOOK
AT YOUR SLIDES.
OKAY, SO MOVEMENT.
IT CAN HAPPEN WITHIN SECONDS,
AS IT DID IN THIS PHOTOGRAPH,
WHICH WAS FROM 2005 IN
CALIFORNIA.
AND IT CAN HAPPEN SLOW, LESS
THAN -- EVEN LESS THAN A CENT
METER PER YEAR.
 -- LESS THAN A CENTIMETER PER
YEAR, BUT IT'S STILL A TAPE OF A
LANDSLIDE.
IT'S STILL THE MASS MOVEMENT OF
MATERIAL DOWNWARD DUE TO
GRAVITY.
AND AS YOU CAN SEE FROM THIS
PHOTOGRAPH, THAT IS CLEARLY MUD.
SO WATER WAS ADDED AT SOME
POINT.
SO IT FLOWS DIFFERENTLY.
IT MOVES DIFFERENTLY.
IT'S A DIFFERENT TYPE OF
MATERIAL THAN IN THE PREVIOUS
PHOTOGRAPH WHERE IT WAS VERY
DRY.
BUT THE MATERIAL IS CATEGORIZED
INTO TWO MAIN TYPES, IT'S EITHER
BEDROCK, SO IT'S A LARGE, VERY
LARGE, CONSOLIDATED CHUNK OF
ROCK.
OR IT'S UNCONSOLIDATED, SO IT'S
A TYPE OF SOIL.
AND THAT CAN BE MADE UP OF
DEBRIS, WHICH IS VERY COARSE
GRAINED MATERIAL, SO IT CAN BE
ANYWHERE FROM SIZES LIKE THIS
ALL THE WAY DOWN TO MUCH SMALLER
OR IT CAN BE PIECES THIS LARGE.
BUT THEY'RE UNCONSOLIDATED.
IT'S LOOSE.
BUT THEY'RE FAIRLY LARGE.
AND THEN WE HAVE THE CATEGORY OF
EARTH, WHICH IS VERY FINE
GRAINED.
SO THINK OF SAND, SILT, CLAYS.
AND THEN IF YOU TAKE THE FINE
GRAINED SEDIMENTS AND YOU ADD
WATER TO THE MIX, YOU'LL CREATE
MUD.
SO NOW WE'RE ON TO THE TYPES OF
MOVEMENT.
WE HAVE FLOW, FALL, AND SLIDE.
AS YOU CAN SEE FROM THE DIAGRAM,
A FLOW WOULD BE SOMETHING LIKE
MUD, ALTHOUGH AN UNCONSOLIDATED
COARSE GRAINED ROCK MIXTURE WITH
WATER COULD ACTUALLY FLOW AS ONE
UNIT AS WELL.
SO IT PRETTY MUCH STAYS TOGETHER
AND IT MOVES AS ONE UNIT AND
IT'S FLOWING DOWN THE SLOPE.
A FALL IS WHEN A LARGE CHUNK OF
BEDROCK BREAKS OFF, IT COULD BE
DUE TO A FAULT, A FOLIATION
PLANE.
IT COULD BE AN EARTHQUAKE AND IT
WAS LOOSE AND IT JARS IT.
BUT IT FREEFALLS.
IT JUST BREAKS OFF AND FALLS
STRAIGHT DOWN.
SO IT DOESN'T RIDE OR GLIDE
ALONG ANY TYPE OF SLOPE.
AND THEN WE HAVE A SLIDE.
SO THE DESCENDING MASS MAY OR
MAY NOT STAY INTACT, IT'S
PROBABLY GOING TO BREAK AND
CRACK A LITTLE BIT ON THE WAY
DOWN.
BUT IT'S JUST GOING TO SLIDE.
IT'S JUST LIKE WHEN YOU GO DOWN
A SLIDE.
IT'S JUST GOING TO RIDE ON THAT
SLOPE ALL THE WAY DOWN.
BUT WE HAVE TWO TYPES.
WE HAVE TRANSLATIONAL WHERE IT
JUST SIMPLY GOES DOWN.
AND THEN THERE'S ALSO
ROTATIONAL, WHERE IT STARTS TO
TURN A LITTLE BIT.
AND THE TERM FOR THAT IS SLUMP.
SO IT LOOKS VERY MUCH LIKE IT
SOUNDS.
IT'S JUST SORT OF SLUMPING ON
DOWN.
IT'S NOT A SMOOTH MOVEMENT.
SO THE CONDITIONS MAY BE RIPE
FOR A LANDSLIDE, BUT WHETHER OR
NOT YOU ACTUALLY HAVE A
LANDSLIDE DEPENDS UPON IF
THERE'S A TRIGGER.
SO IF YOU TAKE ANY ONE OF THESE
THREE, GRAVITY, WATER, OR THE
TRIGGERS, OUT, YOU CHANGE THE
SITUATION AND YOU MAY OR MAY NOT
HAVE A LANDSLIDE EVEN THOUGH THE
CONDITIONS ARE RIPE.
BUT IF YOU TAKE ONE OF THESE
AWAY, YOU PROBABLY WILL NOT HAVE
ONE.
SO GRAVITY AFFECTS THE LANDSLIDE
LIKE WE -- LIKE YOU PROBABLY
ALREADY HAVE GUESSED.
PULLING IT DOWNWARD.
WE CALL THIS SHEAR FORCE.
IT CAN ALSO BE CALLED SHEAR
STRESS, AS IT IS IN THE DIAGRAM.
SO IT'S PULLING THE OBJECT OR
THE ROCK DOWN THE SLOPE
PARALLEL.
IT -- THE STEEPER THE SLOPE, THE
MORE LIKELY IT IS TO MOVE, AND
ALSO THE FASTER IT'S GOING TO
MOVE.
THE SHEAR STRENGTH IS THE
RESISTANCE TO THE MOVEMENT.
AND THAT'S GOING TO BE
CONTROLLED BY THE COHESIVENESS
OF THE MATERIAL.
IS IT REALLY SOLID?
IS IT REALLY PUT TOGETHER WELL?
OR IS IT KIND OF LOOSE AND
BROKEN UP?
IN WHICH CASE IT WOULD -- IT
WOULD CREATE A LANDSLIDE EASIER
AND IT WOULD MOVE FASTER.
ALSO, THERE'S FRICTION BETWEEN
THE PARTICLES, AND WATER PLAYS
INTO THIS AS WELL.
AND ALSO, THE ANCHORING EFFECT
OF ROOTS OF PLANTS.
VEGETATION AND TREES, THEY DO
A -- THEY PLAY A HUGE ROLE IN
HOLDING THINGS IN PLACE.
AND CREATING STRENGTH.
SO WHEN WE REMOVE THAT, THAT'S
WHY AFTER CLEAR-CUTTING WE GET A
LOT OF LANDSLIDES AND MUD FLOWS.
SO IF THE SHEAR STRENGTH IS
GREATER THAN THE SHEAR FORCE,
YOU'RE NOT GOING TO HAVE ANY
MOVEMENT.
IF IT'S THE OPPOSITE, THE SHEAR
FORCE IS GREATER THAN THE SHEAR
STRENGTH, YOU'RE GOING TO HAVE
MOVEMENT.
NOW THE FUN PART: WATER.
AND THIS IS A BEAUTIFUL PHOTO OF
SOMEBODY'S FANTASTIC SAND
CASTLE.
SO ANYBODY WHO'S EVER BUILT A
SAND CASTLE BEFORE OR EVEN JUST
PLAYED IN THE SAND WITH A
BUCKET, YOU KNOW THAT WATER CAN
HELP, IT CAN HELP MAKE THINGS
STRONGER, IT CAN HELP STICK THAT
SAND TOGETHER.
BUT IF YOU HAVE TOO MUCH, IT CAN
DESTROY IT.
SO IF YOU TRY TO BUILD A SAND
CASTLE WITH DRY SAND, YOU'RE NOT
GOING TO BE ABLE TO MAKE ONE,
IT'S GOING TO JUST SORT OF
CRUMBLE AND FALL APART.
IF YOU HAVE A LITTLE BIT OF
WATER IN THERE, IT'S GOING TO
HOLD TOGETHER.
IT'S GOING TO BE JUST RIGHT.
YOU'RE GOING TO BE ABLE TO BUILD
A FANTASTIC CASTLE, LIKE WE SEE,
IF YOU HAVE THAT KIND OF SKILL,
WHICH I DON'T.
BUT IF YOU HAVE TOO MUCH WATER,
IF YOU DUMP A BUCKET OF WATER ON
TOP OF THIS, IT'S JUST GOING TO
GO EVERYWHERE.
SO WITH SOIL AND ROCKS, IT'S THE
SAME THING.
IF IT'S TOO DRY, IT WILL CREATE
A LANDSLIDE.
IF IT HAS JUST A LITTLE BIT OF
WATER, IT CAN HELP HOLD THINGS
TOGETHER.
BUT IF YOU HAVE TOO MUCH WATER,
IT'S OVERSATURATED.
THEN IT'S JUST GOING TO SLIP AND
SLIDE.
SO TRIGGERS.
IN THE LAST COUPLE WEEK, WE
COVERED TWO OF THE BIG TRIGGERS
FOR LANDSLIDES.
EARTHQUAKES AND V VOLCANIC
ERUPTIONS.
SO IF YOU'VE GOT SOME ROCKS ON A
CLIFF AND THEY'RE NOT ON THERE
TOO SECURELY AND ALL OF A SUDDEN
YOU SHAKE IT, THEY'RE GOING TO
COME DOWN.
ANOTHER TRIGGER IS HEAVY RAINAL.
SO -- RAINFALL.
SO LIKE WE SAW WITH THE SAND
CASTLE, IF YOU OVERSATURATE THAT
IT'S GOING TO COME DOWN.
AND THEN IF YOU BUILD ON THESE
AREAS THAT ARE NOT THAT -- YOU
KNOW, THEY'RE NOT BEING HELD
TOGETHER THAT MUCH, THEY'VE GOT
SOME CRACKS, IT'S, YOU KNOW, ON
A SLOPE AND YOU PUT A HEAVY
BUILDING ON THERE, YOU'VE NOW
INCREASED THE WEIGHT AND IT'S
GOING TO WANT TO COME DOWN.
ANOTHER THING THAT HUMANS DO
WHEN THEY'RE BUILDING ROADS IS
YOU CUT INTO THE ROAD, CUT INTO
THE ROCKS TO MAKE THE ROAD.
YOU'RE CUTTING OFF THE BASE OF
THE SLOPE.
WHICH CAUSES THE ROCKS TO NOT
HAVE THAT STABLE FOUNDATION SO
THEY WANT TO JUST SLIDE DOWN.
IF IT'S AN AREA PRONE TO
LANDSLIDES.
SO NOW, HERE'S A LITTLE NATIONAL
GEOGRAPHIC PIECE SHOWING A
LANDSLIDE HERE.
[ SCREAMS ]
A MOUNTAIN BEGINS TO MOVE AND
FOR HIS CONTRACTOR AND HIS SON,
THERE'S ONLY ONE OPTION -- GET
OUT OF THE WAY, FAST.
[ SCREAMS ]
>> NO, NO, NO, NO!
FASTER!
GO, GO, GO!
GET OUT OF THE WAY!
>> OH MY GOD!
>> THEY HAD JUST GONE
HEAD-TO-HEAD WITH ONE OF
NATURE'S MOST POWERFUL AND
DESTRUCTIVE FORCES.
A LANDSLIDE.
THE SURFACE OF OUR PLANET IS
CONSTANTLY RESHAPING ITSELF, AND
LANDSLISLIDES ARE A MAJOR REASO.
THEY STRIKE WHERE WHEREVER THE
SOIL IS LOOSENED BY RAIN OR
TUGGED BY CAVITY.
IT CAN BE A ROCKFALL OR A RAGING
RIVER OF MUD.
BUT WHEREVER THE GROUND FAILS,
IT CAN RESULT IN MASSIVE
DESTRUCTION.
ON AVERAGE, LANDSLIDES KILL MORE
THAN 8,000 PEOPLE EVERY YEAR
AROUND THE WORLD.
THEY CAN CRASH DOWN WITHOUT
WARNING AND TRAVEL FOR SEVERAL
MILES.
IN THE U.S., LANDSLIDES OCCUR IN
ALL 50 STATES, BUT SOME PLACES
ARE MORE DANGEROUS THAN OTHERS.
LANDSLIDES USUALLY FOLLOW OTHER
NATURAL DISASTER, LIKE VOLCANIC
ERUPTIONS, EARTHQUAKES,
WILDFIRES, STORMS, AND FLOODS.
STEEP SLOPES ARE OBVIOUS PLACES
FOR LANDSLIDES, AS ARE AREAS
THAT HAVE BEEN HIT BY LANDSLIDES
BEFORE.
BUT THEY ALSO FREQUENTLY OCCUR
WHERE PEOPLE HAVE RADICALLY
ALTERED THE LANDSCAPE.
HILLS VIPED OF VEGETATION.
 -- STRIPPED OF VEGETATION.
SLOPES MODIFIED FOR ROADS AND
BUILDS.
AND AS OUR CITIES AND TOWNS
EXPAND FURTHER, LANDSLIDES
BECOME MORE FREQUENT AND MORE
DESTRUCTIVE.
[ SCREAMS ]
IN 1998, DISASTER STRUCK THE
SOUTHERN CALIFORNIA SUBURB OF
LAGUNA NIGUEL.
FEW REALIZE HAD THE MAN-MADE
HILL BENEATH THEM COULD FAIL.
THE GROUND ERODED BY HEAVY RAINS
BEGAN TO GIVE WAY.
AND THE HOUSES CAME CRASHING
DOWN.
SEVEN WERE SERIOUSLY DAMAGED,
AND FIVE OF THEM TUMBLED DOWN
THE CLIFF FACE.
THOUGH THE GROUND CRACKED AND
THE EARTH PLUMMETED, NO ONE WAS
INJURED.
THE RESIDENTS OF LAGUNA NIGUEL
WERE LUCKY, THEY STILL HAD THEIR
TOWN.
THE FOLLOWING YEAR, IN
VENEZUELA, TORRENTIAL RAINS
TRIGGERED WIDESPREAD LANDSLIDES
ACROSS A 25-MILE WIDE STRIP OF
COASTLINE IN THE STATE OF
VARGAS.
COMMUNITIES WERE BURIED UNDER
WAVES OF MUD AND DEBRIS.
IT'S ESTIMATED THAT 30,000
PEOPLE WERE KILLED, AROUND 10%
OF THE AREA'S POPULATION.
ACCURATE DEATH TOLLS WERE
DIFFICULT TO ESTABLISH BECAUSE
SO MANY PEOPLE VANISHED UNDER
THE MUD OR WERE SWEPT OUT TO
SEA.
THOUGH THE CATASTROPHE WAS ON A
MASSIVE SCALE, IT IS BY NO MEANS
UNIQUE.
SUCH DISASTERS HAVE HAPPENED
BEFORE, AND WILL HAPPEN AGAIN.
AS LONG AS THE EARTH CONTINUES
TO MOVE, PEOPLE WILL LIVE WITH
THE THREAT OF LANDSLIDES.
>> Heather: THOSE HOUSES IN
CALIFORNIA IN LAGUNA NIGUEL, SHE
SAID WHAT FAILED WAS A MAN-MADE
MOUNTAIN THAT THEY WERE SITTING
ON, AND THEN THE RAINS CAME AND
WASHED IT AWAY.
WELL, IT'S INTERESTING, LATER
WHEN WE GET INTO THE FLOOD
PORTION, RAISING BUILDINGS UP
WITH MAN-MADE LITTLE MOUNTAINS
AND JUST RAISING THE SOIL LEVEL
AND RAISING BUILDINGS UP ABOVE
FLOOD LEVEL IS ONE WAY THAT
ENGINEERS ARE STARTING TO THINK
THAT WE COULD AVOID FLOODS IN
THE FUTURE.
BUT IF YOU COMBINE THAT WITH
THIS, IT MAY OR MAY HOT BE A
GOOD IDEA.
MAYBE YOU'RE GOING TO AVOID THE
FLOOD, BUT, YOU KNOW, MAYBE THE
RAIN OR THE WATER IS JUST GOING
TO WASH THAT MAN-MADE MOUNTAIN
AWAY.
SO AS WE GET INTO THIS WITH
LANDSLIDES AND FLOODS, THERE'S A
LOT OF THINGS YOU'LL SEE WHERE
WE TRY TO MITIGATE ONE, BUT IT'S
ACTUALLY THE CAUSE OF ANOTHER.
SO... IT'S ONE OF THOSE NOT
REALLY A GOOD SOLUTION
SITUATIONS.
OKAY, SO ON TO THE DIFFERENT
TYPES OF LANDSLIDES.
SO WE HAVE CREEP, AND LIKE IT
SOUNDS, CREEPING ALONG JUST
VERY, VERY SLOW, ALMOST
IMPERCEIVABLE MOVEMENT.
THEN WE HAVE FLOWS SUCH AS A
MUDSLIDE, MUD FLOW.
ROCKFALLS AND ROCKSLIDES.
AND UNDERWATER LANDSLIDES.
CREEP IS VERY, VERY SLOW INDEED.
IT CAN ACTUALLY BE LESS THAN A
CENTIMETER IN A YEAR.
SO UNLESS YOU'RE TAKING A
MEASUREMENT, YOU'RE NOT GOING TO
SEE THIS.
NOW, IF YOU HAVE SOMETHING BUILT
ON LAND THAT'S CREEPING, AFTER
YEARS AND YEARS, YOU MIGHT START
WITNESSING SOME VISIBLE SIGNS IN
THE MAN-MADE BUILDINGS.
IF YOU HAVE A FENCE, IT MIGHT
START BOWING OR BENDING WHERE
THE CREEP IS.
IF YOU HAVE ELECTRIC LINES OR
ELECTRIC POLES THEY'LL START TO
BEND.
AND UNFORTUNATELY IF YOU HAVE A
HOUSE THAT'S SITTING ON LAND
THAT'S CREEPING YOU'RE GOING TO
START NOTICING SOME CRACKS IN
YOUR WALLS, MAYBE YOUR CEMENT
DRIVEWAY IS STARTING TO CRACK
AND CRUMBLE A LITTLE BIT.
AND EVENTUALLY YOU'RE GOING TO
HAVE SOME MAJOR STRUCTURAL
DAMAGE.
AND THIS CREEP OCCURS GENERALLY
BECAUSE OF WETTING AND DRYING
CYCLES AND FREEZING AND THAWING
CYCLES.
SO AS WE FREEZE, WE EXPAND A
LITTLE BIT AND THEN WE THAW, WE
CONTRACT.
WHEN THINGS ARE WET, THEY EXPAND
A LITTLE, DRY THEY SHRINK DOWN.
SO YOU HAVE THIS MOVEMENT IN THE
SOIL WHERE THINGS ARE GETTING
BIGGER AND SMALLER, BIGGER AND
SMALLER.
SO EVENTUALLY THINGS START TO
MOVE AROUND.
AND EVEN IF THE SLOPE IS NOT
VERY GREAT, EVEN IF YOU JUST
BARELY GOING DOWNHILL, THINGS
ARE STILL EVENTUALLY GOING TO GO
DOWNHILL.
SO IT'S VERY SLOW.
THERE'S AN INTERESTING
PHENOMENON WITH THIS.
WHEN TREES ARE GROWING ON LAND
THAT'S CREEPING, THEY WILL
COMPENSATE FOR THE CREEP BECAUSE
THEY DON'T WANT TO WIND UP AT AN
ANGLE LIKE THAT.
THEY'RE ALWAYS GOING TO GO UP.
AND YOU'VE PROBABLY NOTICED THIS
WITH YOUR HOUSE PLANTS LEANING
TOWARDS THE SUN, YOU GOTTA
ROTATE YOUR POT TO KEEP YOUR
PLANTS STRAIGHT.
WELL, WHAT THE TREE DOES IS IT
BENDS ITS TRUNK AND STARTS TO
GROW SO IT'S FACING DIRECTLY UP
TOWARDS THE SUN.
SO YOU GET THESE BEND IN ALL OF
THESE TREES ALONG LAND THAT'S
CREEPING.
AND, AGAIN, WITH TREES AND
PLANTS, THEY HELP TO ANCHOR
THINGS.
SO IF YOU HAVE LAND THAT'S
CREEPING VERY, VERY SLOWLY, AND
YOU CLEAR-CUT THAT LAND, THE
CREEP IS GOING TO START CREEPING
A LOT FASTER.
AND THEN THIS IS A LITTLE VIDEO
OF A GUY WHO'S TREKKING THROUGH
THE FOREST IN JAPAN AND HE COMES
ACROSS AN ENTIRE FIELD OF TREES
THAT ARE COMPENSATING FOR CREEK.
 -- FOR CREEP.
>> LUCKY HERE AND I ARE
DESCENDING ON THIS VERY STEEP
HILLSIDE AND WE'VE COME ACROSS A
TREE THAT IS EXEVERYONE LIVERY
AS IT ILLUSTRATES A PHENOMENON
CALLED CREEP.
A GEOLOGICAL PHENOMENON THAT
OCCURS WHEN THE SEDIMENT AND THE
SOIL OF A HILLSLIDE SLOWLY MOVE
DOWN THE HILL,AGEUALLY.
YOU CAN SEE -- I SHOULD PROBABLY
STEP BACK A LITTLE BIT.
WHOA!
BETTER -- CAN YOU SEE HOW THIS
LARGE TREE HAS COME OUT OF THE
GROUND AND MAKES AN ANGLE UP?
LIKE THAT?
THAT'S ITS COMPENSATION FOR
CREEP.
THIS ENTIRE HILLSLIDE IS SLOWLY
MOVING DOWNSLOPE AT PROBABLY A
PERCEPTIBLE RATE.
AND AS YOU COMPENSATE THE TREE
HAS BEEN GROWING AT AN ANGLE
LIKE THAT, TO COMPENSATE, TO
REMAIN IN A VERTICAL POSTURE.
IT'S AN OLD TREE AND HAS A
BEAUTIFUL LINES IN IT
ILLUSTRATING -- THIS PHENOMENON
ILLUSTRATES A FASCINATING
CONCEPT OF GEOLOGY, CREEP.
YOU CAN SEE IT ALL OVER THE
WORLD ESPECIALLY IN HUMID PLACES
WHERE THERE'S LOTS OF RAINFALL.
>> Heather: I'VE NEVER SEEN
ANY IN PERSON, BUT I HAVE SEEN
SOME PROGRAMS -- PHOTOGRAPHS OF
TREES GROWING ON SOIL THAT'S
CREEPING AND THE TREE HAS
COMPENSATED SO MUCH THAT IT'S
ACTUALLY GROWING IN A 90-DEGREE
ANGLE.
SO JUST IT'S AMAZING.
SO FLOWS.
FLOWS CAN MOVE SLOWLY.
THEY CAN ALSO MOVE VERY QUICKLY.
AND THERE'S MANY DIFFERENT KINDS
OF FLOWS DEPENDING ON WHAT TYPE
OF MATERIAL IS FLOWING.
SO EARTH'S FLOW IS BASICALLY
SOIL.
AND IT MOVES DOWN SLOW AS A
FLUID.
AND THIS GENERALLY OCCURS AFTER
A HEAVY RAIN OF COURSE.
SOLIFLUCTION IS WHEN SOIL
BECOMES OVERSATURATED DUE TO
OVERLYING AN IMPERMEABLE
MATERIAL SUCH AS BEDROCK OR
PERMAFROST.
SO WHAT HAPPENS IS NORMALLY WHEN
IT RAINS IT GOES INTO THE SOIL
AND THEN IT WILL SLOWLY TRICKLE
DOWN AND MAKE ITS WAY THROUGH
INTO AN AQUIFER AND GROUNDWATER.
WELL, IN CERTAIN AREAS, WE HAVE
SOLID BEDROCK OR IN ALASKA WE
HAVE PERMAFROST.
SO WHAT HAPPENS IS THE SOIL
CAN'T HOLD THAT MUCH WATER.
AND THE EXCESS WATER HAS NOWHERE
TO GO DOWNWARD.
IT HITS THIS SOLID -- THIS SOLID
WALL AND IT CAN'T GO ANY
FARTHER.
SO IT BECOMES OVERSATURATED
VERY, VERY QUICKLY.
AND IT STARTS TO MOVE.
AND FLOW.
SO IT'S VERY SIMILAR TO AN EARTH
FLOW.
AND THEN A DEBRIS FLOW IS GRAVEL
AND BOULDERS, SO WE HAVE VERY
LARGE CHUNKS OF ROCK.
AND IF THERE'S ENOUGH WATER, IT
CAN BEHAVE JUST LIKE A MUD FLOW.
SO NATURALLY IT'S NOT DISSOLVING
INTO THE WATER LIKE MUD, BUT
IT'S MOVING AS A COHESIVE UNIT
IN THE WATER.
IT'S A MIXTURE OF THE WATER AND
THE ROCKS AND IT'S FLOWING
DOWNWARD.
SO THEN WE MOVE ON TO MUD.
SO MUD IS WHEN IT ACTUALLY
DISSOLVES IN THE WATER.
IT'S VERY SMALL PARTICLES.
SOIL, SILT, CLAY AND IT MOVES
DOWN A CHANNEL.
IT'S USUALLY ABOUT AS THICK AS A
MILK SHARE AND IT'S VERY COMMON
IN AREAS WHERE THERE'S NOT
GROUND COVER TO PROTECT THE
SOIL.
SO THOSE AREAS ARE ARID REGIONS,
DESERTS, AND EVEN ON THE SIDES
OF VOLCANOS IF YOU GET A
TORRENTIAL RAIN THAT RAIN STARTS
TO MIX WITH THE ASH THAT'S BUILT
UP ON THE SIDE OF THE VON KINDO
AND CAN ACTUALLY CREW -- VOLCANO
AND CAN CREATE A MUD FLOW DOWN
THE SIDES.
THEN THERE'S A DEBRIS AVALANCHE
WHICH IS THE FASTEST.
THESE OCCUR IN SECONDS OR
MINUTES.
THEY'RE VERY TURBULENT AND
THEY'RE A MIX OF DEBRIS, AIR AND
WATER, ALL MIXED AND ROLLING
TOGETHER.
IT'S JUST SO FAST IT JUST ALL
ROLLS DOWN AND YOU SEE THESE BIG
CLOUDS BURST INTO THE AIR.
INTERESTINGLY, THERE'S STILL A
DEBATE GOING ON IF THE MIX OF
AIR INTO THIS MASS IS MAKING IT
MOVE FASTER OR MAKING IT MOVE
SLOWER.
THERE'S TWO SIDES TO THAT
DEBATE, SOME THINK THAT THE AIR
IS KIND OF PROTECTING STUFF AND
SLOWING IT DOWN.
OTHERS THINK THE AIR IS JUST IN
THERE MIXING IT UP AND MAKING IT
MOVE FASTER.
SO NOW WE'RE GOING TO WATCH
ABOUT A MINUTE OF A DEBRIS FLOW.
SO AS YOU -- WHEN YOU WATCH IT
YOU CAN SEE HOW IT'S MOVING LIKE
A FLUID.
BUT IT'S ACTUALLY BIG CHUNKS OF
ROCK.
SO THE DIFFERENCE BETWEEN THAT
AND THE DEBRIS AVALANCHE IS THE
DEBRIS AVALANCHE WOULD BE MUCH,
MUCH FASTER.
THIS WAS MOVING AT A FAIRLY SLOW
RATE.
AND IT LOOKED LIKE THERE WAS
SOME WATER MIXED IN.
THERE DOESN'T HAVE TO BE WATER
IN IT TO BE A DEBRIS FLOW.
BUT THAT PARTICULAR ONE, IT
LOOKED LIKE THERE WAS SOME WATER
MIXING IN, WHICH WOULD MAKE IT
MOVE FASTER.
SO ROCKFALLS AND ROCKSLIDES.
A ROCKFALL WOULD BE A LARGE
CHUNK OF BEDROCK.
SO VERY INTACT, LARGE PIECE THAT
JUST BREAKS OFF.
IT DOESN'T SLIDE DOWN.
IT JUST FALLS DIRECTLY DOWN.
SO IT'S USUALLY A CLIFF OR AN
OVERHANG AND A PIECE JUST DROPS
AND BREAKS DOWN.
A ROCKSLIDE WOULD BE IF THAT
SAME PIECE WERE TO JUST SLIDE
DOWN THE MOUNTAIN.
IF IT HAD A SLOPE THAT IT COULD
SLIDE DOWN.
AND THESE USUALLY BREAK ALONG
SOME TYPE OF PLANE OF WEAKNESS.
SO AN AREA WHERE MAYBE THERE WAS
A FRACTURE OR A FAULT, FOLIATION
PLANES OR LAMINATIONS WHERE THE
LAYERS WERE LAID DOWN.
SOMETIMES IN LIKE -- IF YOU'VE
EVER LOOKED AT SOME SEDIMENTARY
ROCKS WHEN YOU'RE DRIVING OUT AT
A ROAD CUT AND YOU SEE THE
LAYERS IN THEM.
SO THOSE LAYERS, SOMETIMES THEY
JUST FOLIATE.
THEY COME APART PRETTY EASILY
ALONG THERE.
SO THAT'S WHERE THESE ROCKS
WOULD BE BREAKING OFF, THESE
LARGE BEDROCK PIECES.
AND IN A ROCK AVALANCHE, THEY'RE
BROKEN UP.
SO THEY'RE LITTLE PIECES
BREAKING OFF AND THEY'RE SORT OF
MIXING UP, BUT IT'S VERY FAST,
VERY TURBULENT AND IT JUST COMES
DOWN AS ONE GIANT MASS.
SO THEY'RE THE SAME AS THE
DEBRIS AVALANCHE EXCEPT THESE
ARE WITH BEDROCK.
NOW, THIS IS A ROCK AVALANCHE
THAT OCCURRED IN THE SWISS ALPS
A FEW YEARS AGO.
AND YOU CAN SEE JUST HOW FAST IT
OCCURS.
I MEAN IF YOU'RE UNDER IT,
THERE'S -- YOU'RE NOT GOING TO
ESCAPE.
>> Heather: LANDSLIDES CAN
ALSO OCCUR UNDERWATER.
AND AS WE'VE SEEN IN THE PAST
FEW WEEKS, THERE'S A WHOLE LIST
OF THINGS THAT CAN CAUSE
TSUNAMIS, AND THIS IS ANOTHER
ONE.
SO ALONG THE CONTINENTAL SHELF,
SO ON THE EDGE OF A CONTINENT,
THE OCEAN DOESN'T START RIGHT
WHERE THE CONTINENT ENDS.
THE CONTINENT GETS THINNER AND
THINNER AND THINNER UNTIL
FINALLY YOU REACH THE DEEP
OCEAN.
AND WHAT SOMETIMES HAPPENS ALONG
THIS CONTINENTAL SHELF IS PIECES
START TO BREAK OFF AND WE HAVE
LANDSLIDES VERY SIMILAR TO HOW
WE DO ON LAND.
AND WHEN THESE START TO MOVE
DOWNWARD AND SLIDE DOWNWARD,
THEY SUDDENLY PUSH THE WATER UP.
THEY'VE DISPLACED A LARGE AMOUNT
OF WATER.
AND THEN WE HAVE A TSUNAMI.
SO AN EARTHQUAKE CAN TRIGGER A
TSUNAMI.
AN EARTHQUAKE CAN ALSO TRIGGER
AN UNDERWATER LANDSLIDE, WHICH
IN TURN TRIGGERS A TSUNAMI.
SO THE TSUNAMI JUST -- THERE'S
MANY, MANY THINGS THAT CAN
TRIGGER ONE, AS WE'VE SEEN.
SO HUMANS AND THEIR ENGINEERING
AND BUILDING, WE'VE NOW GOTTEN
TO THE POINT WHERE WE REALIZE
WHERE LANDSLIDE-PRONE AREAS ARE.
PEOPLE DIDN'T USED TO KNOW
EXACTLY WHERE THEY WERE.
AND, YOU KNOW, AS SCIENCE AND
TECHNOLOGY IMPROVES, WE'VE
LEARNED WHERE TO BUILD AND WHERE
NOT TO BUILD.
BUT WE STILL HAVE AREAS WHERE
WE'RE INHABITING WHERE THERE'S
RISK.
SO THEN COMES ALONG CONTROL AND
STABILIZATION.
SO THE FIRST -- THE FIRST WAY OF
TRYING TO MITIGATE THESE RISKS
IS SIMPLY DON'T BUILD IN RISKY
AREAS.
AND THEN WE ALSO HAVE IMPROVED
BUILDING CODES AND REGULATIONS,
ESPECIALLY FOR ROAD CUTS AND
BUILDING HIGHWAYS, SLOPE ANGLES,
GRADING.
AND OF COURSE WATER DRAINAGE AND
CONTROL.
BECAUSE WE'VE SEEN HOW WATER CAN
BE A TRIGGER FOR THESE.
IT CAN ALSO CAUSE THINGS TO MOVE
FASTER.
EXCAVATING AND SOMETIMES
RECONTOURING THE SIDE OF A
MOUNTAIN.
AND RETAINING DEVICES.
SO YOU CAN SEE IN THE PHOTOGRAPH
THAT THEY HAVE THIS MESH WIRE
OVER THE ROCK FACE.
AND THEN THEY HAVE THESE BOLTS
WITH PLATES AND NUTS ON THEM.
THAT IS ALMOST IDENTICAL TO WHAT
THEY DO IF YOUR HOUSE HAS
FOUNDATION ISSUES AND THEY COME
IN AND STABILIZE YOUR
FOUNDATION.
SO IT'S THE SAME CONCEPT,
THEY'RE JUST DOING IT ON A ROCK
FACE INSTEAD OF ON YOUR BASEMENT
WALL.
SO NOW WE'LL GO AHEAD AND LOOK
AT SOME HISTORIC LANDSLIDES.
SO THERE'S THE 1928 ST. FRANCIS
DAM IN LOS ANGELES.
THE 1963 LANDSLIDE IN THE
ITALIAN ALPS.
1970 IN PERU.
AND I EVEN FOUND ONE IN KANSAS,
IT WAS HARD TO FIND ONE, BUT
THERE WAS.
I DID FIND A LITTLE INFORMATION
ABOUT ONE.
LANDSLIDES DO OCCUR IN ALL 50
STATES, BUT THE GREATER THE
SLOPE AND ANGLES OF ELEVATION,
THE MORE LIKELY YOU ARE TO HAVE
ONE.
AND WE'RE QUITE FLAT HERE.
SO IT'S NOT A HUGE RISK.
BUT IT CAN HAPPEN.
AND THEN IN 2018, THERE WAS SOME
MAJOR MUD FLOWS IN SOUTHERN
CALIFORNIA.
IN 1928, AT THE ST. FRANCIS DAM
NEAR LOS ANGELES, THERE WAS A
MAJOR ROCKSLIDE.
SO IT BROKE THE DAM, JUST A YEAR
AFTER IT WAS BUILT.
IT KILLED 400 PEOPLE.
NOW, WHAT'S SO SAD ABOUT THIS
ONE IS IT WAS ENTIRELY CAUSED BY
DESIGN AND CONSTRUCTION
BLUNDERS.
THEY COMPLETELY IGNORED THE
GEOLOGIC PROBLEMS THAT WERE
THERE.
THEY COULD SEE THEM, THEY KNEW
THEY WERE THERE, BUT THAW
IGNORED THEM.
SO IT WAS BUILT ON AN AREA THAT
HAD PREVIOUS LANDSLIDES.
THERE WAS EVIDENCE OF LANDSLIDES
ALL OVER THIS AREA.
THE ROCK IN THE AREA WAS A
CONGLOMERATE.
A CONGLOMERATE IS A SEDIMENTARY
ROCK THAT HAS DIFFERENT SHAPED
LITTLE PIECES OF ROCKS THAT ARE
ALL CEMENTED TOGETHER.
YOU'VE PROBABLY ALL SEEN ONE AT
SOME POINT.
IT'S LIKE IF YOU TAKE LITTLE
RIVER ROCKS AND IT'S IN A MATRIX
AND IT JUST GETS SORT OF
LITHIFIED AND PUSHED TOGETHER
HARD.
SO IT'S NOT A VERY SOLID, STABLE
ROCK.
IT CAN BREAK APART PRETTY
EASILY.
AND THIS PARTICULAR
CONGLOMERATE, ANYTIME THEY WOULD
PUT A PIECE IN WATER, IT JUST
CAME APART.
SO THE MATRIX WAS VERY WATER
SOLUBLE.
SO NOT THE STABLE AREA TO BE
BUILDING A DAM.
AND THEN TO TOP IT OFF, IT WAS
BUILT ON A FAULT.
SO AS WE LEARNED BEFORE, THAT'S
A TRACKTURE WHERE THERE'S --
FRACTURE WHERE THERE'S EVIDENCE
OF MOVEMENT.
SO JUST A REALLY BAD THING.
AND IT WAS BUILT BY AN A TEXT
AND ENGINEER MULLHOLLAND, IT'S A
VERY FAMOUS NAME FROM
CALIFORNIA.
SO HERE'S A LITTLE PIECE ON IT.
>> THE LOS ANGELES AQUEDUCT
CONSTRUCTED FROM 1907 TO ITS
OFFICIAL OPENING IN 1913 BROUGHT
WATER FROM THE HIGH SIERRA
AQUIFER THROUGH A STRING OF
ARTIFICIAL RESERVOIRS CONNECTED
BY GIANT PIPES AND CANALS.
200 MILES ACROSS THE DESERT TO
LOS ANGELES.
IT ALLOWED THAT SMALL CITY ON
THE COAST TO GROW INTO A
MEGALOPOLIS, THE MASSIVE PROJECT
WAS BUILT AHEAD OF SCHEDULE AND
UNDER BUDGET BY A TEXT WILLIAM
MULLHOLAND.
WITHOUT THE AQUEDUCT THERE WOULD
BE NO LOS ANGELES AS WE KNOW IT
TODAY.
BUT THERE WAS A HUMAN PRICE TO
PAY FOR ALL THAT SPEED AND
ECONOMY.
PART OF THE AQUEDUCT PROJECT WAS
A DAM AND RESERVOIR SYSTEM,
INCLUDING AN ART FICTION LIKE
CREATED BY A GRAVITY DAM IN
SAN FRANCISCO -- SAN FRANCUSCITO
CANYON.
THE DAM HAD BEEN FULL FOR TWO
YEARS SERVING AS TERMINAL WATER
STORAGE FOR THE CITY OF
LOS ANGELES.
THOUGH IT WAS LEAKING BADLY, NO
WARNINGS WERE GIVEN.
AND JUST BEFORE MIDNIGHT ON
MARCH 12th, 1928, THE
ST. FRANCIS DAM BURST.
12 BILLION GALLONS OF WATER WERE
RELEASED INTO THE CANYON.
A WALL OF WATER, 125 FEET HIGH,
ROARED DOWNSTREAM AND 450 PEOPLE
BELOW THE DAM DROWNED IN THEIR
BEDS.
IT WAS THE WORST MAN-MADE
DISASTER IN CALIFORNIA HISTORY.
DOCUMENTED BY THIS HISTORICAL
RE-CREATION AND FOOTAGE FROM THE
DEPARTMENT OF WATER AND POWER.
>> THE DAM IS LOCATED AT OVER TO
MY LEFT HERE.
IT SPANNED FROM THE POINT I AM
AT, WHICH IS THE RIGHT ABUTMENT
OR WEST ABUTMENT, CROSSED THE
CANYON TO THE LEFT, WHICH WAS
THE LEFT ABUTMENT, OR EAST
ABUTMENT.
>> LITTLE REMAINS OF THE DAM IN
THIS CANYON TODAY.
NOTHING MARKS THE SPOT WHERE
CONCRETE ONCE STOOD 185 HIGH AND
AN ARTIFICIAL LAKE FLOODED THIS
ENTIRE VALLEY.
>> WHEN THE RESERVOIR STARTED TO
FILL, THE WATER WOULD PERCOLATE
INTO THE SIDES OF THE HILLS ON
EACH SIDE OF THE DAM.
AND IT BECAME SATURATED ALONG
THE OLD LANDSLIDE PLANES.
AND SO AT THE POINT IN TIME WHEN
THE -- IT WASN'T THERE, THEN IT
STARTED TO MOVE DOWN.
AND CAUSE THAT ABUTMENT TO GIVE
AWAY, CAUSING VENN,LY THE DAM.
SO IT WAS A SORT OF A SCONEBLE
OPERATION.
>>CYTICS SAY THE MASSIVE LOSS OF
LIFE WAS CAUSED NOT BY FLAWED
GEOLOGY, BUT BY MULLHOLLAND'S
PERSONALITY.
THE DAM HAD BEEN LEAKING BADLY,
WELL BEFORE IT COLLAPSED.
IN FACT, LOCALS WERE SO
CONCERNED, THEY BROUGHT THE
GREAT MAN UP THERE JUST ONE DAY
BEFORE THE FATAL DISASTER TO SEE
FOR HIMSELF.
>> MULLHOLLAND WAS CALLED OUT
THE THE DAM THE DAY BEFORE IT
FAILED TO INSPECT WHAT WAS
SIGNIFICANT LEAKING BEFORE THE
ACTUAL RELEASE OF THE DAM
OCCURRED.
AND HE ASSURED EVERYBODY THERE
THAT IT WAS FINE, THIS WAS
NORMAL LEAKAGE FOR A DAM, WHICH
OF COURSE IT WAS NOT.
>> THE ST. FRANCIS DAM COLLAPSE
FORCED A SET OF LAWS DESIGNED TO
PREVENT SUCH AN OCCURRENCE
AGAIN.
WILLIAM MULLHOLLAND HIMSELF WAS
DEVASTATED BY THE STRA TRAGEDY
AND SPENT THE REST OF HIS LIFE
IN S SECLUSION.
>> Heather: WITH SO MANY OF
THESE NATURAL DISASTERS YEARS
AGO, THEY WERE SO DEVASTATING
BECAUSE PEOPLE JUST IGNORED THE
SIGNS.
SO I THINK WE'RE IN A MUCH
BETTER SPOT TODAY.
WE'VE LEARNED TO BE MORE
CAUTIOUS AND TO TAKE A LOT OF
THESE THINGS INTO CONSIDERATION
AND TAKE THEM SERIOUSLY SO IN
1963 IN THE ITALIAN ALPS THERE
WAS A ROCK AVALANCHE.
SO THIS WAS VERY FAST-MOVING.
IT MOVED AT 100 KILOMETERS PER
HOUR.
AND IT DEPOSITED A ROCK PILE
THAT WAS OVER 140 METERS HIGH.
UNFORTUNATELY 2,500 PEOPLE WERE
KILLED.
AND IT DISPLACED AN ENTIRE
RESERVOIR.
IT JUST SCOOPED IT RIGHT OUT AND
MOVED THE WATER ON DOWN.
SO THIS IS A LITTLE BRITISH NEWS
PIECE FROM 1963.
AND THERE'S NO SOUND.
THIS ONE IS SILENT.
BUT IT TAKES YOU AROUND AND IT
SHOWS YOU THE DESTRUCTION.
AND THE PEOPLE EVACUATING.
AND THAT'S THE TRAIN TRACK.
IT LIFTED IT UP AND BENT IT
BACK.
AND IT JUST COMPLETELY DECIMATED
THE VILLAGE THAT WAS IN ITS
PATH.
IN 1970 IN PERU, THERE WAS AN
EARTHQUAKE.
BUT THIS EARTHQUAKE TRIGGERED A
DEBRIS AVALANCHE.
IN ADDITION TO THOUSANDS OF
ROCKSLIDES AND FALLS, AND TO TOP
IT OFF, IT DISLODGED A GLACIER.
SO IT WAS JUST ONE THING
TRIGGERING ANOTHER.
THE FIRST THING IT DID AS IT WAS
COMING DOWN IS IT BURIED A SMALL
VILLAGE.
IT JUST COMPLETELY COVERED 1800
PEOPLE.
AND THEN AS IT CONTINUED DOWN,
IT HIT THIS LITTLE CURVED AREA
AND IT JUST SHOT EVERYTHING UP
IN THE AIR.
AND THEN IT WAS ABLE TO CONTINUE
EVEN FARTHER DOWN AND IT COVERED
THE TOWN OF YUNGAY.
AND THERE IT KILLED 17,000
PEOPLE.
SO THIS WAS A HUGE TRAVESTY.
IT KILLED A LOT OF PEOPLE.
IT'S A CLASSIC MOVIE TONE NEWS.
>> DISASTER IN PERU WHEN A LAKE
HIGH IN THE ANDES WEAKENED BY A
SEVERE EARTHQUAKE BURST ITS
DEPTH.
THE TORRENTIAL SWEPT AWAY TWO
MOUNTAIN TOWNS AND SEVERAL
SMALLER COMMUNITIES.
THE PERUVIAN GOVERNMENT CALLED
FOR EIGHT DAYS OF NATIONAL
MOURNING FOR THE 50,000 PEOPLE
BELIEVED TO HAVE PERISHED.
THEY ALSO ALLOCATED
7 MILLION POUNDS FOR
RECONSTRUCTION AND THE
RESETTLEMENT OF 300,000 HOMES.
WRITTEN IS A -- BRITAIN IS AMONG
THE COUNTRIES SENDING FOOD,
SUPPLIES AND MEDICAL AID TO THE
STRICKEN AREA.
95% OF ALL BUILDINGS HAVE BEEN
DESTROYED AND AMID THE CHAOS THE
SURVIVORS PRESENT A PITIFUL
PICTURE AS THEY WAIT FOR FOOD,
CLOTHING AND SHELTER.
>> Heather: BECAUSE OF WHERE
PERU AND CHILE ARE SITTING,
THEY'RE SO TECTONICALLY ACTIVE,
THAT THEY HAVE ALL OF THESE
DISASTERS.
VOLCANOS, EARTHQUAKES,
LANDSLIDES.
UNFORTUNATELY THEY GET HIT WITH
A LOT OF THESE.
AND NOW HERE'S THE KANSAS
LANDSLIDE THAT I FOUND.
IT OCCURRED IN 1995.
AND IT DESTROYED ONE $400,000
HOME.
AND THIS IS AN ACTUAL PHOTOGRAPH
OF IT.
SO IT DIDN'T HURT ANYBODY,
DIDN'T KILL ANYBODY.
IT ALSO DAMAGED FOUR VACANT
LOTS.
UNFORTUNATELY, I COULD NOT FIND
ANYTHING EXPLAINING WHY THIS ONE
OCCURRED.
SO I'LL CONTINUE SEARCHING AND
HOPEFULLY I CAN FIND IT BY NEXT
WEEK AND SHARE IT WITH YOU GUYS.
BUT IT'S VERY INTERESTING.
YEAH, SO IT ONLY DESTROYED ONE
BUILDING.
SO IT WASN'T THE MOST EXCITING.
BUT...
IN 2018, IN SOUTHERN CALIFORNIA,
THERE WERE MASSIVE MUD FLOWS.
SO THESE FOLLOWED HORRIBLE
WILDFIRES.
SO THE WILDFIRES TOOK OUT THE
TREES, THE VEGETATION,
EVERYTHING THAT WAS HOLDING THAT
LOOSE SOIL DOWN.
AND THEN DIRECTLY AFTER THAT,
THEY WERE HIT WITH RAINS.
SO THE RAINS WERE GREAT AFTER A
FIRE.
YOU KNOW, HELPS PUT THE FIRE
OUT, PREVENT MORE FIRE.
BUT AT THE SAME TIME, YOU'VE NOW
REMOVED WHAT'S HOLDING THAT SOIL
DOWN, SO THE RAINS MIXED WITH
THE SOIL CREATES MUD AND IT
STARTS TO MOVE BECAUSE WE'RE IN
AN AREA WHERE THERE'S A LOT OF
SLOPES.
IT KILLED 23 PEOPLE.
AND IT CAUSED $177 MILLION IN
PROPERTY DAMAGE.
$7 MILLION IN EMERGENCY
RESPONSES.
AND $43 MILLION IN CLEAN-UP.
SO BESIDES THE DESTRUCTION THAT
THESE NATURAL DISASTERS CAUSE,
THEY'RE ALSO VERY, VERY
EXPENSIVE.
>> WE BEGIN WITH THOSE SCENES OF
DEAF STATION COMING IN NOW AFTER
THE WILD FIRES NOW STAGGERING
AMOUNTS OF RAIN TRIGGERING
DEADLY MUDSLIDES TONIGHT IN
CALIFORNIA.
MUD AND DEBRIS RUSHING
DOWNHILLS, ON TO MAJOR HIGHWAYS,
SHUTTING DOWN THE 101 IN
MONTECITO.
RAIN SLICK ACCIDENTS ON RAIN
SLICK ROADS.
POWERFUL OR THE RENTS OF MAIN
AND MUD RIPPING UP TRIPS AND
HOME, TRAPPING PEOPLE INSIDE.
IN FACT, A 14-YEAR-OLD GIRL
PULLED FROM THE MUD AND WRECKAGE
LIVE.
BUT NOT EVERYONE HAS BEEN SAVED
AND THE DEATH TOLL IS GROWING.
ABC LEADS US OFF FROM
CALIFORNIA.
>> TONIGHT RESCUERS TRUDGING
THROUGH CHEST-HIGH MUD IN THE
FRANTIC SEARCH FOR THE MISSING.
>> WE HAVE MULTIPLE REPORTS OF
PEOPLE TRAPPED.
>> UP TO 5 INCHES OF RAIN
SURGING THROUGH CREEK BEDS WITH
TITANIC FORCE.
>> IT'S OUR WORST FEAR COMING TO
LIFE FOR US RIGHT NOW.
AND OUR PEOPLE ARE OUT THERE
TRYING TO DO THE BEST WORK THEY
CAN AND PERFORM AS MANY RESCUES
AS THEY POSSIBLY CAN.
>> THE THOMAS FIRE, LARGEST IN
CALIFORNIA HISTORY, DILUTED THE
NEARBY HILLS OF VEGETATION AND
ANYTHING THAT WOULD ABSORB THE
WATER.
OVERNIGHT, THE FAMED 101 FREEWAY
OVERRUN.
>> WE'RE RETREATING HERE.
AND YOU CAN ACTUALLY FEEL DEBRIS
HITTING THE CAR RIGHT NOW.
CLOSED FOR 30 MILES IN BOTH
DIRECTIONS.
YOU CAN SEE HOW FAST THAT WATER
IS MOVING HERE!
I MEAN THAT IS A OR THE RENT OF
WATER.
 -- TORRENT OF WATER.
EIGHT KILLS AND TWO DOZEN
INJURED.
RESCUERS PILING IN OVERNIGHT
GINGERLY PULLING OUT THIS
14-YEAR-OLD GIRL SO MUD
SPATTERED IT'S HARD TO MAKE HER
OUT.
DOGS WERE SENT THROUGH THE DEEP
SLOP SKIRTING AROUND TREES THAT
HAD SNAGGED SIDING, CARS, AND
WHOLE CHUNKS OF HOMES.
FIREFIGHTERS ARE TELLING US THAT
THAT FOUNDATION RIGHT THERE, IT
HAD A HOUSE ON IT.
THAT HOUSE IS NOW OVER THERE
SMASHED UP AGAINST THOSE TREES.
THAT CREW ON THE ROOFTOP
SEARCHING FOR SIGNS OF LIFE.
DO YOU THINK SOMEONE IS IN
THERE?
>> WE HAVE A STRONG FEELING
SOMEONE IS IN THAT HOUSE.
>> SOME NEIGHBORHOODS UP
PASSABLE.
HELICOPTERS AND HIGH WATER
VEHICLES TAKING FAMILIES LIKE
BEN HYATT'S TO SAFETY.
>> I IMMEDIATELY RAN, WOKE UP
ZACH AND PUSHED HIM TO THE TOP
BUNK BED.
I WAS WORRIED IT WAS JUST GOING
TO KEEP COMING AND COMING.
I WOKE UP MY WIFE AND WE JUST
DID NOT KNOW WHAT TO DO BECAUSE
WE WERE SURROUNDED BY MUD.
>> THE DEBRIS FIELD WAS A MILE
LONG RIVERET OF MUD, BOULDERS
AND REMAINS OF PEOPLE'S HOMES.
ABOVE BURBANK, LOOK AT ALL THE
WATER THAT CAME DOWN THROUGH
THIS DAM, DESTROYED LOOKS LIKE
SEVERAL VEHICLES AND THAT RV
THERE.
>> THAT SLIDE ALSO CAUSING A GAS
LEAK AND BRINGING MANDATORY
EVACUATIONS.
>> REPORTING IN TONIGHT FROM
MONT SEDA.
WE KNOW JUST A DEVASTATING SCENE
THERE.
YOU'VE BEEN REPORTING ALL DAY ON
THIS AND THIS AREA WAS NOT UNDER
A MANDATORY EVACUATION?
>> THAT'S RIGHT, DAVID.
WE'VE LEARNED THAT SEVERAL OF
THE NEIGHBORHOODS WE'VE SEEN
HAVE BEEN SWALLOWED BY THESE
DEBRIS FLOWS WERE UNDER
VOLUNTARY EVACUATION ORDERS.
AND OFFICIALS SAY THAT MANY OF
THE RESIDENTS WHO LIVED IN THOSE
MANDATORY EVACUATION AREAS JUST
STAYED PUT.
AND WHEN YOU SEE THE KIND OF
CONCRETE-LIKE MUD THAT RESCUERS
AND FIRST RESPONDERS HAVE TO
DEAL, WITH YOU UNDERSTAND WHY
THEY FEAR THE WORST FOR THOSE
VICTIMS WHO ARE STILL MISSING.
DAVID.
- ALL RIGHT.
JUST INCREDIBLE SCENE TONIGHT.
MATT GUTMAN LEADING US OFF.
>> HI.
THANKS FOR CHECKING OUT THE ABC
NEWS YouTube CHANNEL.
>> Heather: OKAY.
THIS IS A GOOD STOPPING POINT
FOR US TO TAKE OUR 10-MINUTE
BREAK BEFORE WE MOVE ON TO
FLOODS.
>> Heather: AND FLOODS ARE
SOMETHING THAT WE'RE AT A MUCH
HIGHER RISK FOR THAN LANDSLIDES.
AND EVEN LAST YEAR THERE WAS
SOME MASS I FLOODING IN WICHITA.
IT'S SOMETHING WE SEE EVERY FEW
YEARS.
SO...
SO THE FIRST STEP IN
UNDERSTANDING FLOODS IS TO JUST
LEARN A LITTLE BIT OF BASIC
KNOWLEDGE ABOUT THE HYDROLOGIC
CYCLE AND HOW THE WATER IS
MOVING AROUND THE GLOBE FROM
ONE -- ONE SPHERE INTO THE
OTHER.
SO IT'S AN INTERCHANGE OF WATER
BETWEEN SEA, AIR, AND LAND.
SO WE'RE ALL FAMILIAR WITH
PRECIPITATION, AND WHEN THE RAIN
FALLS, SOME OF IT WILL TRICKLE
DOWN INTO THE GROUND, SOME CAN
GO INTO LAKES.
IT CAN RUN OFF INTO STREAMS AND
RIVERS.
SOME OF IT CAN FREEZE.
AND THEN ONCE GROUNDWATER AND
LAKES AND RIVERS AND WATER ON
THE GROUND, IT CAN ALL EVAPORATE
UP AND THEN IT CAN BECOME
CONDENSATION AND PLANTS GIVE OFF
WATER IN THE TRANSPIRATION, SAME
WAY HUMANS DO WHEN WE BREATHE,
WHEN WE RESPIRATE, WE'RE PUTTING
OUT A CERTAIN AMOUNT OF WATER.
WATER IS JUST, IT'S CALLED THE
CYCLE.
BUT FOR ME I THINK OF IT MORE
LIKE A WEB BECAUSE IT'S JUST
MOVING AND TRANSFERRING IN FORM
JUST OVER HERE, OVER THERE, BACK
AND FORTH.
IT'S JUST ALL OVER THE PLACE.
IT'S NOT REALLY PERFECTLY
CYCLICAL.
SO WHEN IT RAINS, SOME OF IT CAN
GO INTO THE GROUND.
SOME WILL FREEZE.
SOME WILL RESATURATE THE SOIL.
BUT THERE'S A CERTAIN PERCENTAGE
OF IT THAT HAS NOWHERE TO GO.
AND IT RUNS OFF.
AND IT WINDS UP IN STREAMS AND
THEN RIVERS.
SO THAT'S USUALLY ABOUT 15 TO
20% OF THE RAINFALL WINDS UP
AS RUNOFF.
IF YOU HAVE A PERIOD OF HEAVY
RAIN WHERE THE RAIN IS
CONTINUOUS AND IT JUST KEEPS
COMING AND YOU REACH THAT FULL
SATURATION POINT OF THE SOIL AND
THE GROUND AND THERE'S JUST
NOWHERE ELSE THE WATER CAN GO,
THERE'S NOTHING THAT WILL HOLD
IT ANYMORE, YOU GET TO A POINT
WHERE YOU'RE AT 100% RUNOFF.
SO FROM THAT POINT FORWARD, ALL
THE RAIN JUST RUNS RIGHT OFF AND
IT GOES INTO THE RIVERS.
THE RIVER CAN ONLY MOVE SO FAST.
IT CAN ONLY TAKE THAT WATER OUT
TO THE OCEAN AT A TOP RATE.
AND IT GETS TO A POINT WHERE IT
CAN'T -- IT CAN'T MOVE IT
AS FAST AS IT'S COMING IN.
AND SO IT STARTS TO FLOW OVER
THE BANKS OF THE RIVER AND THEN
ON TO THE FLOODPLAIN.
AND THAT'S WHEN FLOODING OCCURS.
IN GEOLOGY, WE DON'T USE THE
TERM RIVER.
WE USE THE TERM STREAM.
GENERALLY, AND TRADITIONALLY, WE
THINK OF A STREAM AS , YOU KNOW,
JUST A LITTLE TINY NICE GENTLE
STREAM.
WE USE THE TERM STREAM, CREEK,
RIVER TO DESIGNATE SIZE, THE
SIZE OF THE BODY OF MOVING
WATER.
IN GEOLOGY, THEY'RE ALL A
STREAM.
SIZE DOESN'T MATTER.
WE JUST USE THE TERM STREAM.
WHICH IS ANY BODY OF WATER --
RUNNING WATER THAT'S CONFINED TO
A CHANNEL AND MOVING DOWNWARD
DUE TO GRAVITY.
SO THAT CAN BE A SMALL TRICKLE,
IT COULD BE EVEN A LITTLE TINY
TRICK UNTIL YOUR YARD, THAT
WOULD BE A STREAM.
OR THE LARGEST RIVER, THE
MISSISSIPPI RIVER, THAT'S A
STREAM.
GEOLOGICALLY SPEAKING.
AND NOW I THREW A LITTLE WORD IN
HERE JUST FOR FUN, BECAUSE I
LIKE THE WORD QUITE A BIT AND
IT'S A GEOLOGY WORD, RIPARIAN.
IT'S A FANCY WORD.
YOU CAN IMPRESS PEOPLE WITH IT.
IT MEANS ANYTHING HAVING TO DO
WITH A RIVER.
SO YOU CAN TELL YOUR FRIENDS,
YOU KNOW, LET'S GO HAVE SOME
RIPARIAN ENTERTAINMENT THIS
AFTERNOON.
SOMETHING LIKE THAT.
THEY WON'T KNOW WHAT YOU'RE
TALKING ABOUT.
SO BUT IT JUST MEANS YOU'RE
GOING TO GO DO SOMETHING AT THE
RIVER.
THAT'S JUST A LITTLE BIT OF FUN
TRIVIA THERE FOR YOU.
SO A STREAM RUNS IN ITS CHANNEL.
SO A CHANNEL IS JUST A LONG,
NARROW DEPRESSION WHERE OVER
TIME WATER HAS FLOWED DOWNHILL
AND IT'S CARVED OUT AND PICKED
UP SEDIMENT AND JUST CARRIED IT
DOWN UNTIL IT'S DEPOSITED
ELSEWHERE.
AND THEN RIVER BANKS ARE ON THE
SIDE OF THE CHANNEL, AND YOU GO
A LITTLE FARTHER OUT AND YOU
REACH THE FLOODPLAINS ON THE
SIDES OF A STREAM.
THE BED OF A STREAM IS THE
BOTTOM.
AND HERE'S A LITTLE PROFILE
DIAGRAM OF THE DIFFERENT PARTS
OF A STREAM.
AND ALL STREAMS, ALL
SURFACEWATER EVENTUALLY WINDS UP
BEING DISCHARGED INTO THE OCEAN.
SO THIS IS A MAP OF THE UNITED
STATES.
BUT NO MATTER WHERE YOU ARE IN
THE WORLD, THERE'S DRAINAGE
BASINS.
SO IT'S THE INTERCONNECTEDNESS
OF ALL THESE DIFFERENT STREAMS
AND THEN THEY FLOW INTO A LARGER
STREAM AND A LARGER STREAM UNTIL
EVENTUALLY THEY MAKE IT SOUTH OR
ACTUALLY DOWNWARD SLOPE INTO AN
OCEAN WHERE THEY'RE DISCHARGED.
SO FOR WHERE WE ARE IN THE U.S.,
THE ARKANSAS OR ARKANSAS,
DEPENDING WHERE YOU'RE AT, RIVER
EVENTUALLY DRAINS TO THE
MISSISSIPPI AND WINDS UP IN THE
GULF OF MEXICO.
THIS IS WHY AGRICULTURAL RUNOFF
IS SUCH AN ISSUE IN THE MIDWEST.
IT EVENTUALLY ALL MAKES IT TO
THE MISSISSIPPI AND THE GULF OF
MEXICO, WHICH HAS BEEN CAUSING
SOME ANOXIC, OR LACK OF OXYGEN
CONDITIONS AND ALGAL BLOOMS.
SO WE'VE ALREADY COVERED
PRECIPITATION, WHICH IS THE MOST
COMMON CAUSE OF FLOODING, JUST
TOO MUCH WATER.
EXCUSE ME.
BUT THERE'S OTHER CAUSES OF
FLOODING AS WELL.
THE OTHER CAUSES ARE NOT VERY
COMMON, BUT THEY DO OCCUR.
ONE IS AN ICE JAM.
IN COLDER AREAS, UPSTREAM IN A
RIVER, THE WATER WILL FREEZE AND
THEN AS IT STARTS TO THAW A
LITTLE BIT IT WILL BREAK LOOSE
AND IT TRAVELS DOWNSTREAM.
AND IT CAN HIT AN AREA WHERE
IT'S JAMMED.
AND IT STARTS TO BUILD UP.
IT BUILDS UP TO A POINT WHERE
THE RIVER WATER STARTS TO BACK
UP AND EVENTUALLY COMES OVER THE
BANKS AND CREATES FLOODING.
IT'S A TEMPORARY FLOOD AND
AS SOON AS TEMPERATURES WARM UP
AND THE ICE MELTS, THE WATER
CONTINUES DOWN THE CHANNEL.
HURRICANES AND STORM SURGES CAN
CAUSE FLOODING, BRINGING MASSIVE
AMOUNTS AND MASSIVE WALLS OF
WATER ON TO LAND.
DAMS CAN FAIL, AS WE SAW AT THE
ST. FRANCIS DAM.
EARTHQUAKES CAN CAUSE TSUNAMIS
AND IN TURN THAT TSUNAMI CAN
CAUSE FLOODING.
SO YOU COULD SAY TSUNAMIS CAUSE
FLOODING.
YOU ALSO SAY EARTHQUAKES CAUSE
FLOODING.
AND THEN THERE'S ALSO LONG-TERM
CAUSES OF FLOODING.
ONE OF THOSE IS SEA LEVEL RISE.
THEY'RE NOT AS DESTRUCTIVE, AND
YOU DON'T NOTICE THEM.
SOME OF THEM MAY TAKE HUNDREDS
OF YEARS BEFORE AN AREA FLOODS.
BUT IF YOU LOOK AT MAPS OF
COUNTRIES AND DEPENDING ON WHAT
TIME IN HISTORY YOU'RE CHOOSING
THERE MIGHT BE A CITY THAT'S NO
LONGER THERE THAT'S NOW
UNDERWATER.
IF THE SEA CONTINUES TO RISE,
ONE OF THE FIRST PLACES FOR US
THAT'S GOING TO BECOME
UNDERWATER IS FLORIDA.
IF ALL THE ICECAPS MELT,
EVENTUALLY KANSAS COULD BE
SEA-FRONT PROPERTY.
SO IT'S A TYPE OF FLOODING, IT'S
JUST A VERY SLOW OCCURRING
FLOODING.
THEN WE ALSO HAVE SUBSIDENCE,
WHICH IS WHEN LAND JUST STARTS
TO SINK AND GET LOWER.
SO IF YOU'RE ALONG THE COASTLINE
AND YOU START TO SINK, YOU'RE
GOING TO BE LOWER THAN SEA LEVEL
AND THE WATER IS GOING TO COME
THIS.
SO THAT'S ANOTHER TYPE OF
LONG-TERM FLOODING.
FLOODING CAN ALSO BE CAUSED BY
MAN-MADE AC ACTIVITIES.
AND THE LITTLE INFOGRAPHIC
MENTIONED SOME OF THOSE.
INCREASED URBANIZATION.
SO WHEN IT RAINS, THE SOIL AND
THE GROUND ACTS LIKE A GIANT
SPONGE.
FOR EVERY PIECE OF LAND WHERE WE
HAVE A BUILDING, A HOUSE, A
DRIVEWAY, A ROAD, A PARKING LOT,
WE'VE COVERED THAT SOIL.
IT CAN'T ABSORB DIRECTLY
ANYMORE.
NOW, WHEN IT RAINS DOWN IN OTHER
AREAS, A CERTAIN AMOUNT OF THAT
SATURATION WILL WORK OVER AND BE
ABSORBED BY THAT.
BUT NOT ALL OF IT.
SO WHEN THE RAIN HITS PAVEMENT,
IT GOES INTO OUR DRAINAGEWAYS
AND GETS ROUTED TO THE RIVER.
A LOT OF THAT WATER, IF WE
DIDN'T HAVE A CITY HERE, WOULD
HAVE JUST WENT INTO THE GROUND
AND NEVER WOULD HAVE MADE ITS
WAY TO THE RIVER.
SO THAT'S A LARGE INCREASE IN
WATER THAT'S MAKING ITS WAY TO
THE RIVER, WHICH CAN INCREASE
THE RISKS OF FLOODING.
THEN THERE'S ALSO FARMING
PRACTICES.
IF A FARMER IS LEAVING A FIELD
COMPLETELY EMPTY, WATER WILL RUN
OFF IT MUCH FASTER AND EASIER
THAN IT WOULD IF THE LAND WAS
COVERED IN CROPS.
WHICH NOT ONLY SLOW THE MOVEMENT
OF THE WATER AND THE RUNOFF, BUT
THEY ALSO USE A LOT OF THAT
MOISTURE THAT'S IN THE GROUND.
AND THEN DEFORESTATION.
ONCE AGAIN, WHEN YOU REMOVE THE
PLANTS AND THE VEGETATION, THE
WATER RUNS OFF A LOT FASTER AND
IT'S NOT BEING USED UP BY THESE
PLANTS.
SO THE WATER -- SO THE WATER
RUNS OFF AT A MUCH FASTER RATE.
IF YOU THINK OF -- IF YOU HAVE A
SPOT IN YOUR YARD WHERE IT'S
JUST DIRT AND THEN YOU HAVE A
SPOT WHERE THERE'S GRASS, IF YOU
WERE TO TAKE YOUR HOSE AND PUT
IT ON THE AREA WITH DIRT, IT
WOULD RUN OFF REALLY FAST.
IF YOU PUT YOUR HOSE ON THE AREA
WITH THE GRASS, IT'S GOING TO
TAKE A LITTLE LONGER TO RUN OFF.
SO IT'S THAT TYPE OF A CONCEPT.
SO SIZE AND FREQUENCY.
THE USGS MONITORS WATER
ELEVATION AND DISCHARGE RATES OF
THE STREAMS IN THE UNITED
STATES.
AND FLOODS ARE BASED ON THEIR
RECURRENCE INTERVALS.
SO WE'VE ALL HEARD ABOUT A
20-YEAR FLOOD, A 100-YEAR FLOOD,
THAT SORT OF THING.
SO IF IT'S A 100-YEAR FLOOD,
IT'S THE LARGEST FLOOD THAT WE
COULD EXPECT TO OCCUR FROM THAT
PARTICULAR STREAM IN 100 YEARS.
SO IT MAKES IT SOUND AS THOUGH
IT WOULD ONLY OCCUR EVERY
HUNDRED YEARS.
THAT'S NOT EXACTLY RIGHT.
WHAT IT IS, IS THAT THERE'S ONLY
A 1% CHANCE EACH YEAR OF A FLOOD
OF THAT SIZE OCCURRING.
SO THAT'S WHY SOME PEOPLE TEND
TO WONDER IF THERE'S A BAD FLOOD
THIS YEAR AND THEN THERE'S
ANOTHER ONE AND THEY'RE BOTH
100-YEAR FLOODS, YOU KNOW, HOW
COULD THAT POSSIBLY HAPPEN?
HOW IT HAPPENS IS THAT EACH
YEAR, YOU HAVE A 1% CHANCE OF
HAVING A FLOOD OF THAT SIZE.
SO YOU COULD HAVE ONE THIS YEAR,
AND THEN YOU COULD HAVE ONE NEXT
YEAR, YOU COULD HAVE ONE THE
YEAR AFTER THAT, OR YOU COULD
HAVE ONE AND THEN NOT HAVE
ANOTHER ONE FOR 500 YEARS.
IT'S JUST THE CHANCE, OR THE
LEVEL OF RISK OF THAT SIZE OF A
FLOOD.
SO HOW DO THEY CALCULATE THAT?
THEY MEASURE AND TAKE THE
MAXIMUM DISCHARGES FROM THE
RIVER.
AND THEY USUALLY MEASURE IT FOR
ABOUT 100 YEARS, YOU KNOW, KEEP
RECORDS.
AND SO THESE NUMBERS ARE ALWAYS
CHANGING AS WELL.
AND THEN ONCE THEY HAVE THOSE
RECORDED, THEY RANK THEM
ACCORDING TO SIZE.
SO THE LARGEST DISCHARGE RATE IS
RANKED AS NUMBER ONE AND THEN
THE SECOND LARGEST AND SO THAT'S
USUALLY LIKE LET'S SAY 1 THROUGH
10 FOR THIS EXAMPLE.
SO YOU WOULD -- YOU RECORDED IT
FOR 10 YEARS, SO YOU'RE GOING TO
TAKE 10 AND THEN YOU'RE GOING TO
ADD ONE.
AND THEN YOU'RE GOING TO DIVIDE
THAT BY THE LARGEST DISCHARGE
RATE.
AND THEN THAT'S HOW YOU GET HOW
MANY YEARS IT WILL BE BEFORE
THAT FLOOD.
IT'S A LITTLE HARD OF A CONCEPT
TO GRASP WHEN YOU'RE JUST
LISTENING TO IT.
SO HERE'S A LITTLE PIECE THAT
EXPLAINS IT BETTER.
AND I TRIED TO FIND ONES WITH
AMERICAN ACCENTS.
THIS ONE IS FROM NEW ZEALAND, SO
IT WAS THE ONLY ONE SHORT ENOUGH
TO FIT IN, THOUGH, SO...
WHY WOULD IT SAY THAT?
OKAY.
WELL, LET'S...
LET'S TRY IT ONE MORE TIME.
OKAY.
APPARENTLY IT DOESN'T WANT TO
PLAY.
SO I'M SORRY.
BUT IT'S SIMILAR TO ROLLING
DICE.
YOU HAVE A CERTAIN CHANCE OF
ROLLING A 6, AND THAT DOESN'T
MEAN THAT YOU'RE NOT GOING TO
ROLL A 6 AGAIN FOR ANOTHER, YOU
KNOW, SIX ROLLS.
SO THERE'S A CHANCE THAT YOU
COULD HAVE A 100-YEAR FLOOD A
LOT MORE OFTEN THAN EVERY
HUNDRED YEARS, OR MUCH LESS
FREQUENTLY.
OKAY.
SO MITIGATION.
AND THIS IS WHERE WE'RE GOING TO
GET INTO WHAT I WAS SAYING
BEFORE ABOUT SOMETIMES WHEN WE
TRY TO MITIGATE LANDSLIDES OR
FLOODS, WE WIND UP CREATING THE
OTHER.
SO IN THE U.S., IN THE LOWER 48,
THERE'S MORE THAN 75,000 DAMS.
AND GENERALLY THE REASON FOR
BUILDING THESE WAS TO HELP
PREVENT FLOODING.
HOWEVER, WHEN A LANDSLIDE OCCURS
OR AN EARTHQUAKE, IF IT BREAKS
THE DAM, WE NOW HAVE MASSIVE
FLOODING.
SO IT'S TRYING TO PREVENT
FLOODING, BUT AT THE SAME TIME
IT CAN CREATE FLOODING.
THIS IS ONE OF THE REASONS WHY
SOME DAMS ARE BEING DISMANTLED.
THE RISK FROM FLOODING SHOULD
THEY BREAK IS TOO GREAT.
AND THE SAME THING WITH
ARTIFICIAL LEVEES ALONG
COASTLINES.
THEY'RE TRYING TO CONTAIN THE
FLOODWATERS, BUT IF THE LEVEE
BREAKS, THERE'S GREATER FLOODING
THAN THERE WOULD HAVE BEEN
WITHOUT THE LEVEE.
AND FOR PEOPLE WHO ARE ALREADY
LIVING IN FLOOD ZONES AND
FLOODPLAINS, THEY PASSED THE
FLOOD INSURANCE ACT OF 1968,
WHICH PROVIDES SUBSIDIZED FLOOD
INSURANCE TO PROPERTY OWNERS IN
THESE FLOOD-PRONE AREAS.
NOW, I DID READ SOMETHING, SO
I'M NOT POSITIVE ABOUT THIS, BUT
I DID READ SOMETHING THAT SAID
THAT IF YOU CURRENTLY BUILT IN
THESE FLOOD AREAS, YOU'RE NOT
GOING TO BE ABLE TO BE PROTECTED
BY FLOOD INSURANCE BECAUSE YOU
ALREADY KNOW THAT IT'S A
FLOOD -- HIGH FLOOD-PRONE AREA.
SO I BELIEVE IT'S ONLY FOR
PROPERTIES THAT HAVE BEEN
GRANDFATHERED THIS.
GRANDFATHERED IN.
AND THEN FLOOD-PROOFING.
THIS IS SOMETHING REALLY GREAT
AND HELPFUL FOR BUILDINGS THAT
ARE IN FLOOD AREAS OR EVEN ONES
THAT ARE NOT IN FLOOD AREAS.
RAISING THE STRUCTURE ABOVE THE
100-YEAR FLOOD LEVEL, THIS IS
ONE THAT'S -- IT SOUNDS REALLY
GOOD AND IT WOULD BE GREAT FOR
PREVENTING DAMAGE FROM FLOODS.
HOWEVER, AS WE SAW IN CALIFORNIA
EARLIER, A MAN-MADE MOUNTAIN IS
REALLY EASY TO WASH AWAY, AND IT
COULD POSSIBLY CAUSE MORE
PROBLEMS.
BUT IN THEORY, IT SOUNDS PRETTY
GOOD ON THE SURFACE FOR
FLOOD-PROOFING.
AND THEN BUILDING WALLS AND
LEVEES, AND AGAIN, THESE CAN BE
BENEFICIAL.
IT CAN ALSO BE WORSE IF DAMAGE
COMES TO THEM.
BUT USING WATER RESISTANT
MATERIALS, THIS -- THIS ONE IS
REALLY GREAT.
IT REALLY LESSENS THE DAMAGE IF
THERE IS A FLOOD.
SO THAT'S A GOOD ONE.
AND THEN FLOODPLAIN MANAGEMENT.
IN A CONGRESSIONAL REPORT AFTER
THE BIG FLOODS OF 1993, CONGRESS
STATED THAT FLOODS ARE AN ACT OF
GOD, BUT FLOOD DAMAGES RESULT
FROM ACTS OF MAN.
SO IF WE MANAGE THE FLOODPLAINS
BETTER, AND WE DON'T BUILD IN
THOSE AREAS, WE CAN REALLY
MITIGATE AND PREVENT A LOT OF
THE DAMAGES FROM THESE FLOODS.
OKAY.
NOW WE'RE GOING TO LOOK AT A FEW
HISTORIC FLOODS.
THERE'S THE 1889 JOHNSTOWN,
PENNSYLVANIA.
THIS IS ANOTHER SITUATION LIKE
WE HAD WITH MULHOLLAND IN
CALIFORNIA WHERE PEOPLE WERE
JUST DISREGARDING SIGNS AND NOT
DOING -- NOT DOING THE REPAIRS
THAT THEY SHOULD HAVE TO THE
DAM.
IN 1900 IN GALVESTON, TEXAS.
PEOPLE WERE COMPLETELY IGNORING
ALL THE WARNING SIGNS THAT CAME
BEFORE A LARGE HURRICANE.
AND IN 1928 IN LIKE OKEECHOBEE
IN -- IN LAKE OKEECHOBEE IN
FLORIDA, LARGE HURRICANE AND IT
ACTUALLY LIFTS AN ENTIRE LAKE UP
AND OUT OF ITS BASIN AND DUMPS
IT ON THE CITY.
1976, THE BIG THOMPSON RIVER IN
COLORADO HAD FLASH FLOODING.
AND THEN IN 1993 IN ST. LOUIS IN
THE MIDWEST THERE WAS MASSIVE
FLOODING.
SO WE'LL LOOK AT THOSE NOW.
SO IN 1889 IN JOHNSTOWN,
THATBALL, THE SOUTH FORK DAM
FAILED AND IT CAUSED A MASSIVE
FLOOD.
IT RELEASED SOME SAY
14 MILLION CUBIC METERS.
I'VE ALSO READ 20 MILLION CUBIC
METERS.
AND IT KILLED 2,200 PEOPLE AND
CAUSED $17 MILLION IN DAMAGE IN
1889.
THIS WAS THE FIRST TIME THAT
CLARA BARTON TOOK THE NEWLY
FORMED AMERICAN RED CROSS TO
HELP WITH A DISASTER AS WELL, SO
IT'S A VERY HISTORIC EVENT.
>> Heather: NOW WE'LL MOVE ON
TO 1900 IN GALVESTON, TEXAS.
THIS WAS THE DEADLIEST NATURAL
DISASTER IN U.S. HISTORY.
EVER.
EVEN TO DATE.
IT KILLED SOMEWHERE BETWEEN
6,000 AND 12,000 PEOPLE.
IT WAS CAUSED BY A GREAT
HURRICANE AND IT DAMAGED EVERY
DWELLING ON THE ISLAND.
AT THIS TIME IN GALVESTON, IT
WAS THEIR GILDED AGE, AND THEY
WERE VERY WEALTHY.
IT WAS BEING BUILT FAST.
IT WAS A BUSTLING, GROWING
ISLAND.
AND THEY STARTED HEARING THESE
REPORTS OF A BIG HURRICANE
COMING.
AND ESPECIALLY COMING IN FROM
CUBA AND THEY WERE SAYING WE
REALLY THINK IT'S GOING TO HIT
GALVESTON, YOU KNOW, YOU NEED TO
EVACUATE.
AND THEY THOUGHT, NO, NO, NO, IT
WILL HIT LAND SOMEWHERE ELSE.
YOU KNOW, IT'S NOT GOING TO HIT
US.
AND THEN IT STARTED HITTING
FLORIDA AND THEY WERE GETTING
MORE REPORTS, YOU KNOW, HEY, YOU
KNOW, IT'S REALLY BAD, IT'S
GOING TO BE EVEN WORSE FOR YOU.
AND ALONG THE COASTLINE, THEY
WERE GETTING THESE REPORTS IN.
OF COURSE BACK THEN, THEY DIDN'T
HAVE THE TECHNOLOGY OR REALLY
GOOD COMMUNICATION, LIKE WE DO
NOW, WHERE IT'S INSTANTANEOUS,
SO THEY WERE GETTING THESE
RESPONSES A LITTLE LATE.
BUT STILL, THEY STILL HAD TIME
TO EVACUATE.
FOR WHATEVER REASON, THEY JUST
INSISTED THAT IT WAS NOT GOING
TO HIT THE ISLAND, IT WAS GOING
TO HIT LAND SOMEWHERE ELSE.
THEY WERE FINE.
SO UNFORTUNATELY IT DID HIT
THEM, IT COVERED THE ISLAND, AND
IT WAS THE WORST AND DEADLIEST
NATURAL DISASTER IN U.S.
HISTORY.
IT JUST DECIMATED THE ISLAND.
I DON'T HAVE A LITTLE VIDEO CLIP
WITH THIS ONE.
BUT THAT'S A PHOTOGRAPH OF THE
ISLAND.
AND EVERY BUILDING WAS EITHER
DESTROYED, COMPLETELY, OR
DAMAGED.
AND AFTER THIS, GALVESTON
NEVER -- NEVER ACHIEVED THE
GREATNESS AND THE RATE OF
EXPANSION THAT THEY HAD AT THAT
TIME.
SO ALL THE MILLIONAIRES AND
MAGNETS AT THE TIME THAT WERE
BUILDING GALVESTON, THEY
ABANDONED IT AND THEY MOVED
INLAND TO HOUSTON, WHICH IS WHY
HOUSTON GREW TO ITS SIZE AND WHY
IT'S REALLY A LARGE CITY.
WAS BECAUSE OF THIS DEVASTATION
THAT OCCURRED.
NOW WE'RE UP TO 1928.
AND THERE WAS A LAKE IN FLORIDA,
LAKE OKEECHOBEE, AND, AGAIN, A
HURRICANE HIT.
SO THIS WAS CALLED THE IS AN
FELIPE SAGUNDO HURRICANE.
THE HURRICANE IN AND OF ITSELF
WOULD HAVE BEEN BAD.
BUT IT WOULD NOT HAVE CAUSED
FLOODING TO THIS DEGREE.
SO IT HIT THIS LIKE AND IT JUST
LIFTED THE WHOLE THING UP, JUST
TILTED IT ON ITS SIDE AND JUST
DUMPED THE WATER DIRECTLY OVER
THE TOWN.
THIS WAS THE SECOND DEADLIEST
NATURAL DISASTER IN U.S.
HISTORY.
AND IT KILLED 2,500 PEOPLE.
AND CAUSED $100 MILLION IN
DAMAGE.
HERE'S A LITTLE CLIP FROM THE
AMERICAN EXPEENS TALKING ABOUT
IT.
 -- THE AMERICAN EXPERIENCE
TALKING ABOUT IT.
[ MUSIC ]
>> Heather: SO THIS WAS
ANOTHER EXAMPLE OF A MAN-MADE
STRUCTURE WHOSE INTENT WAS TO
PREVENT FLOODING AND IT PROBABLY
DID IN SMALLER HURRICANES,
SMALLER EVENTS.
BUT WHEN ONE LARGE ENOUGH HITS
THAT CAN DESTROY THE MAN-MADE
DIKE, THE FLOODING IS MUCH, MUCH
WORSE.
IT'S SIMILAR TO WHAT OCCURRED IN
HURRICANE KATRINA.
SO YOU GOTTA WEIGH THE GOOD WITH
THE BAD, BUT SOMETIMES IT'S
ACTUALLY BETTER TO LET NATURE BE
NATURE.
AND NOT TRY TO CONTROL IT.
NOW WE'RE UP TO 1976 AND THE BIG
THOMPSON ROAR IN COLORADO.
 -- RIVER IN COLORADO.
THIS WAS A FLASH FLOOD THAT
OCCURRED ABOVE THE SOUTH PLATTE
RIVER.
SO A THUNDERSTORM CAME IN AND IT
JUST STAYED STATIONERY AND IT
DIDN'T MOVE OUT.
SO IT JUST KEPT DUMPING MORE AND
MORE WATER AND THEY HAD
12 INCHES OF RAIN IN 4 HOURS.
THAT'S JUST SIMPLY MORE THAN THE
SOIL COULD HANDLE.
SO A FLAG FLOOD CAME -- FLASH
FLOOD CAME DOWN THE CANYON AND
IT HAD A 20-FOOT WALL OF WATER.
IT KILLED 143 PEOPLE AND 5
PEOPLE WERE NEVER FOUND.
A FAST-FORWARD TO 2008.
THERE WAS A WOMAN STUDYING THIS
NATURAL DISASTER AND SHE WAS
TRYING TO LOCATE PEOPLE THAT MAY
HAVE BEEN INVOLVED IN IT AND GET
THEIR STORY OF WHAT HAPPENED.
WELL, SOMEHOW SHE FOUND ONE OF
THE PEOPLE WHO WAS THOUGHT TO
HAVE BEEN KILLED IN THE FLOOD.
AND HE WAS LIVING HAPPY AS CAN
BE IN OKLAHOMA.
WHAT HAD HAPPENED WAS THE
MORNING BEFORE THE FLOOD, HE
LEFT HIS CABIN EARLY.
HE DIDN'T TELL ANYBODY THAT HE
HAD GONE HOME.
SO EVERYBODY JUST THOUGHT THAT
HE WAS THERE AND THEN NOBODY
COULD FIND HIM AFTER THE FLOOD
AND THEY JUST ASSUMED THAT HE
HAD DIED.
SO INTERESTING FACT.
IT DESTROYED 400 CARS, HOUSES,
BUSINESSES, AND MOST OF ROUTE
34.
>> THE BIG THOMPSON FLOOD WAS A
PRODUCT OF BAD TIMING.
>> THE FACT THAT THE FLOOD HIT
AT NIGHT, THAT IT HAD A BUNCH OF
PEOPLE WHO WERE JUST HAVING A
PLEASANT DAY AND NO SIRENS, NO
SIGNALS.
>> THE ONLY WAY THAT PEOPLE
LEARNED ABOUT THE POTENTIAL OF
THE FLOOD WAS THROUGH WORD OF
MOUTH.
BUT THE WORD DID NOT MOVE FASTER
THAN THE FLOOD WATERS ITSELF IN
MANY CASES.
>> Heather: CONSIDERING THE
LACK OF WARNING AND THE FACT
THAT THERE WAS OVER 4,000 PEOPLE
CAMPING THERE, I THINK IT'S AN
AMAZING THING THAT IT ONLY
KILLED 143.
IT COULD HAVE BEEN A LOT WORSE.
SO NOW WE'LL LOOK AT A FEW
KANSAS AND WICHITA FLOODS.
THERE'S A LONG LIST OF THESE.
SO I ONLY PICKED OUT THREE.
IN 1903, THERE WAS A MAJOR FLOOD
THAT FLOODED ALL OF TOPEKA,
LAWRENCE, AND KANSAS CITY.
SO THAT WAS A MASSIVE ONE.
AND THEN 1923 IN WICHITA.
AND A 1951 FLOOD IN MANHATTAN.
IN 1903, IT WAS A VERY COLD
WINTER, BUT IT WAS A VERY WET
WINTER.
THERE WAS A LOT OF RAIN, A LOT
OF SLEET, A LOT OF SNOW.
SO THAT STARTS TO ADD UP WHEN IT
MELTS AND IT STARTS TO SATURATE
THINGS PRETTY GOOD.
AND THEN IN MAY, HEAVY RAINS
CAME.
SALINA ACTUALLY RECEIVED OVER 1.
SO THE FLOODING THAT OCCURRED
WAS SO BAD, THAT THE RAILROADS
HAD TO DISCONTINUE THEIR
SERVICE.
PEOPLE WERE STRANDED ALL OVER
THE THREE CITIES.
IT TOTALED 4,000 PEOPLE WHO HAD
TO LEAVE THEIR HOMES, 57 DIED IN
THE FLOOD.
AND BY JUNE, WHEN THE
FLOODWATERS CRESTED AND STARTED
TO RECEDE, THERE WERE DEAD
ANIMALS, DEAD LIVESTOCK, AND
STAGNANT BODIES OF WATER LEFT.
SO THERE WAS A LARGE PROBLEM
WITH DISEASE THAT CAME
AFTERWARDS.
>> THE DEADLIEST FLOOD IN
TOPEKA'S HISTORY CAME 115 YEARS
AGO THIS WEEK.
THIS IS TIM RIBBARD, THE HISTORY
GUY, TALKING ABOUT THE KANSAS
RIVER FLOOD OF 1903.
THAT FLOOD KILLED 57 PEOPLE,
INCLUDING 38 IN TOPEKA,
ACCORDING TO THE KANSAS STATE
HISTORICAL SOCIETY.
JOHN STRICKRA TOOK THE PHOTOS
SHOWN IN THIS VIDEO OF THE 1903
FLOOD IN TOPEKA.
THAT DISASTER BROUGHT TOPEKA'S
SECOND HIGHEST KANSAS RIVER
RECORD ON LEVEL ECLIPSED ONLY BY
THE FLOOD OF 1951.
THE 1903 FLOOD CAME AFTER A
MONTHLY RAINFALL OF NEARLY
9 INCHES.
AT A TIME WHEN TOPEKA HAD NO
DIKES TO STAVE OFF FLOODWATERS.
THE RIVER CRESTED ON MAY 30th,
1903, AND BECAME 2 TO 3 MILES
WIDE, FORCING 4,000 TO PECANS
FROM THEIR HOMES, MOSTLY IN
NORTH TOPEKA.
MEN IN BOATS RESCUED MANY FROM
THE ROOFTOP OF THEIR FLOODED
HOMES.
WATER DEPTHS REACHED 10 TO
12 FEET IN PARTS OF NORTH
TOPEKA, SHOWN HERE, WHERE
BUSINESS, RAILROAD, AND
INDUSTRIAL DISTRICTS WERE
HEAVILY DAMAGED.
WHEN FLOODWATERS REACHED THE
LINE STORED AT A LOCAL LUMBER
COMPANY SHOWN HERE, FIRE IGNITED
FROM COMBUSTION AND SPREAD TO
BURN THE LUMBERCREDIT CARD.
FLAMING TIMBERS THEN DRIFTED
INTO OTHER BUILDS SETTING THEM
ABLAZE.
THE TOPEKA DAILY CAPITOL
REPORTED THE CRIES OF THOSE
BELEAGUERED IN THE TREE TOPPS
AND ON THE ROOFS OF HOUSES ARE
AUDIBLE A MILE AWAY.
FOR NO BUILDING IS SAFE AGAINST
THE TERRIFIC FORCE OF THE
WATERS, AND MANY HOUSES ARE IN
THE DIRECT TRACK OF THE FIRES
THAT ARE RAGING.
BUT THE FLOODWATERS EVENTUALLY
SUBSIDED.
A DIKE WAS THEN PUT IN PLACE
AFTER NORTH TOPEKA SAW LESS
SERIOUS FLOODING IN 1908.
THIS IS THE HISTORY GUY FOR CJ
ONLINE.
>> Heather: YEAH, HE SAID THE
WATER IN TOPEKA WAS 10 TO
12 FEET HIGH AND WHEN IT CRESTED
THE RIVER WATER ITSELF WAS 2 TO
3 MILES WIDE.
THAT'S A MASSIVE AMOUNT OF
WATER.
AND AS GREAT AS IT WAS, THERE
WAS ONE THAT WAS EVEN WORSE IN
1951, WHICH WE'LL LOOK AT IN A
MINUTE.
SO 1923 IN WICHITA, THERE'S
MASSIVE FLOODING.
AND IT WAS CAUSED BY EXCESSIVE
PRECIPITATION AND RUNOFF.
CAUSED OVER A MILLION DOLLARS IN
DAMAGE AND, AGAIN, TRAIN SERVICE
HAD TO BE SUSPENDED.
DOUGLAS AVENUE ACTUALLY FLOODED
WITH 13.5 FEET OF WATER.
AND THIS IS AN ACTUAL PHOTOGRAPH
FROM THAT TIME WHEN THE WATER
WAS STARTING TO GO BACK DOWN.
I BELIEVE THIS IS THAT BUILDING
THAT'S ON MAIN STREET.
IT DIDN'T SPECIFY IN THE
PHOTOGRAPH.
BUT I BELIEVE THAT'S WHAT IT
LOOKS LIKE.
AND THEN A FLOOD ALMOST
IDENTICAL TO THIS OCCURRED AGAIN
IN 1944.
SO 1951 IN MANHATTAN WAS ONE OF
THE WORST FLOODS EVER.
THEY REFERRED TO IT AS BLACK
FRIDAY BECAUSE IT WAS SO BAD.
IT WAS ALSO ONE OF THE MOST
COSTLY FLOODS THE STATE HAD EVER
SEEN, COSTING $725 MILLION.
IT PRODUCED 18.5 INCHES OF RAIN
ABOVE THE BIG BLUE RIVER.
THE BUSINESS DISTRICT IN
MANHATTAN WAS COVERED IN 8 FEET
OF WATER.
IT DESTROYED 7,000 BUILDINGS,
85,000 PEOPLE HAD TO EVACUATE.
10,000 FARMS WERE DAMAGED.
AND 28 PEOPLE DIED.
IF YOU REMEMBER FROM LAST WEEK'S
LECTURE, WE COVERED THE TUTTLE
CREEK DAM NEAR MANHATTAN.
THIS FLOOD IS THE REASON THAT
THAT DAM WAS BUILT.
AND THAT'S THE DAM WHERE YOU CAN
GO AND THERE'S AN OVERLOOK AND
YOU CAN SEE AN ACTUAL FAULT THAT
THEY PRESERVED.
SO...
SO ONCE AGAIN, THE DAM WAS BUILT
DUE TO THIS FLOODING AND TO
PREVENT THIS TYPE OF FLOODING,
BUT THE TUTTLE CREEK DAM IS
SITTING NOT FAR FROM THE
HUMBOLDT FAULT ZONE.
AND IT'S AT LOW RISK OF ANY
MOVEMENT.
BUT IF IT STARTS TO MOVE AND WE
HAVE A BIG EARTHQUAKE, YOU KNOW,
WHAT DO YOU THINK IS GOING TO
HAPPEN WITH THIS DAM?
IT'S GOING TO BREAK THE DAM AND
THEN WE'RE GOING TO HAVE MASSIVE
FLOODING.
NOW, THIS IS A LITTLE VINTAGE
NEWS CLIP, AND I CHOSE IT
BECAUSE IT'S A BRITISH PIECE.
SO THIS FLOOD WAS SO BAD IN
1951, THAT IT WAS BEING COVERED
BY THE PRESS IN OTHER COUNTRIES.
[ SUSPENSIBLE MUSIC ]
- IN AMERICA'S MIDWEST,
INCREDIBLE DEVASTATION MARKS THE
PATH OF THE FLOOD.
90,000 PIECES OF ROLLING STOCK
HAVE BEEN SWAMPED, BRIDGES
WRECKED AND WHOLE COMMUNITIES
LAID WASTE.
AS THE WATERS SLOWLY RECEDE,
STORES OF TRAPPED CARS ARE
REVEALED.
41 DEATHS ARE SO FAR REPORTED
AND HALF A MILLION PEOPLE ARE
STILL DISPLACED, THEIR HOMES OR
WORKPLACES DAMAGED OR DESTROYED.
FROM WASHINGTON, PRESIDENT
TRUMAN FLIES OVER A MILLION AND
A HALF ACRES OF RUINED CROPS IN
HIS HOME STATE.
WITH HIS EXPERTS HE PLANS RELIEF
ON AN AREA OF 11,000 SQUARE
MILES.
WHILE THE PRESIDENT FLIES
OVERHEAD, SURVIVING LIVESTOCK
SURROUNDED UP, BUT THOUSANDS
MUST PERISH IF HELP CANNOT REACH
THEM IN TIME.
FLOODS PLAY STRANGE TRICKS IN
THEIR PASSAGE, FOR INSTANCE,
HERE'S A PIG ON TOP OF A CAR.
AND WASTE THROUGH THE TOWNS.
HERE'S THE RICH TOP SOIL SWEPT
AWAY BY THE FLOOD.
AS CONGRESS RUSHES THROUGH A
10 MILLION-POUND VOTE, LIVES
SLOWLY RESUMES.
BUT THE DANGER GROWS ELSEWHERE
AS THE FLOODING REACH THE
GREATEST HEIGHT IN A HUNDRED
YEARS.
>> Heather: AND NOW WE'RE UP
TO QUESTIONS.
SO IF ANYBODY HAS ANY QUESTIONS,
REMEMBER TO COME UP TO THE
MICROPHONE HERE.
YES.
>> I HAVE A COMMENT AND A
QUESTION.
I'M SURE THERE'S OTHER PEOPLE IN
THE ROOM THAT HAVE MAYBE LIVED
IN CALIFORNIA.
BUT I LIVED OUT THERE OFF AND ON
FOR 12 YEARS, AND THE MUD ALWAYS
SLIDES AND THE PEOPLE BUILD
THEIR HOUSES AND THEY PAY BIG
BUCKS TO BUILD THEIR HOUSES
THERE.
AND I NEVER COULD UNDERSTAND
WHY.
BUT THEN THEIR HOUSES SLIT DOWN
THE MOUNTAIN -- SLID DOWN THE
MOUNTAIN OR DOWN THE HILL.
MY OTHER QUESTION IS, YOU DID
NOT MENTION THE BIG DITCH HERE
IN WICHITA.
AND THE FACT THAT IT -- IT TAKES
CARE OF THE FLOODING.
AND I CAN REMEMBER AS A SMALL
CHILD AND I'M SURE EVERYBODY
HERE CAN, THAT MY GRANDFATHER
THOUGHT IT WASN'T GOING TO WORK.
YOU KNOW, IT'S WAY BIG WASTE OF
MONEY, IT'S NOT GOING TO WORK.
BUT IT ACTUALLY HAS.
AND I HAVE OLD PICTURES, FAMILY
PICTURES OF THE FLOOD -- OF
FLOODING OFF AND ON.
AND, YOU KNOW, IT USED TO FLOOD
RIVERSIDE AND ALL OF THAT, ALL
THE TIME, AND DOUGLAS.
AND I JUST THOUGHT IT WAS
INTERESTING YOU DIDN'T MENTION
THAT BECAUSE THAT FOR US
LOCALLY, THAT'S A BIG CONTROL,
FLOOD CONTROL.
>> Heather: YEAH.
YOU'RE ABSOLUTELY RIGHT.
THAT'S A PERFECT EXAMPLE OF
LOCAL FLOOD CONTROL AND THAT
PROJECT WAS DONE BY THE USGA
HERE AND THEY CONTINUE TO
MONITOR THAT AND THEY CONTINUE
TO ALTER IT AS WELL.
AND MY FIANCÉ, WHERE HE GREW UP
IN WICHITA IN THE WEST SIDE, HIS
BACKYARD SLOPED DOWN TO ONE OF
THE TRIBUTARIES AND HE
REMEMBERED AS A CHILD LIKE YOU
DID THEIR HOUSE WAS FLOODING
CONSTANTLY.
AND THEY'D HAVE TO KNOCK THE
WALLS OUT IN THE BASEMENT.
AND REBUILD.
AND THEY MADE SOME CHANGES TO
THAT FLOOD CONTROL, I THINK IT
WAS ABOUT 15 YEARS AGO.
AND IT'S HELPED FOR WHERE THEIR
HOUSE IS, IT'S HELPED.
IT HASN'T STOPPED IT 100%, BUT
IT HAS HELPED CONTROL IT.
BUT IF YOU'D LIKE TO BRING SOME
OF THOSE PHOTOS NEXT WEEK, I'D
LOVE TO SEE THEM.
OKAY.
BUT, YEAH, AND ALSO ABOUT THE
HOUSES IN CALIFORNIA, I'VE
WONDERED THAT, TOO, BECAUSE
THEY'RE EXTREMELY EXPENSIVE AND
THEY'RE BUILT IN PRECARIOUS
LOCATIONS, AND EVENTUALLY, YOU
KNOW, A LOT OF THEM DID, THEY
JUST SLID RIGHT ON DOWN.
AND VERY SAD.
[ OFF MIC ]
[ LAUGHTER ]
>> Heather: YEAH.
AND ALSO YOU WOULD THINK THAT
AS A HOME BUYER, KNOWING THAT
THAT RISK IS THERE, YOU'D BE
EXTRA CAREFUL WHERE YOU BUY.
[ OFF MIC ]
>> Heather: YEAH.
YEP.
ARE THERE ANY ONLINE QUESTIONS?
PAT?
OKAY.
ANYBODY ELSE HAVE ANY QUESTIONS
OR COMMENTS?
OKAY.
WELL, THEN I'LL SEE YOU NEXT
WEEK FOR HURRICANES AND
TORNADOES.
