Case Study on Lynmouth Flood 1952 IGCSE

1. LYNMOUTH FLOOD 1952

2. It happened in August of 1952 The size of the river suddenly grew It tossed and turned and ruined lives It killed husbands, children and wives The sun disappeared, the sky turned grey This was no longer an ordinary day The water rose to 40 feet high You could here all around the people cry In the months before there had been lots of rain The ground could no longer become a drain

3. The ground trembled, water came crashing Parents were running, children were splashing When the water came in there was no place to hide The river was loud, fast and wide It came thundering in and took over the land Destroying houses like a giant’s hand (Chloe – Year 8)

4. CAUSES

5. THE ORIGINAL RIVER HAD BEEN NARROWED AND DIVERTED FOR THE CONSTRUCTION OF BUILDINGS IN LYNMOUTH WHICH HAD REDUCED CHANNEL CAPACITY

7. EXMOOR (SOURCE OF RIVER) – GRANITE (IMPERMEABLE ROCK), RESULTING IN LARGE AMOUNTS OF SURFACE RUNOFF

9. LYNMOUTH MARKED WITH THE CONFLUENCE OF THE East AND West LYN RIVERS WITH LARGE AMOUNTS OF WATER MEETING FROM BOTH RIVERS AFTER THE HEAVY RAIN

10. DURING THE FLOOD THE RIVER REJOINED ITS ORIGINAL COURSE

11. A VERY WET AUGUST WITH 12 OUT OF THE FIRST 14 DAYS EXPERIENCING HEAVY RAINFALL RESULTING IN SATURATED GROUND IN EXMOOR.

13. RELATIVELY SMALL DRAINAGE BASIN WITH STEEP SIDES ENCOURAGING RAPID RUN OFF

15. TRIGGERED BY TORRENTIAL RAIN (230mm) IN A 14HOUR PERIOD – ONE OF THE 3 BIGGEST RAINFALLS EVER RECORDED IN THE UK.

17. EFFECTS

19. DEBRIS BUILT UP BEHIND BRIDGES RESULTING IN THE BUILD UP OF WATER...... 34 PEOPLE WERE KILLED IN THE DISASTER

24. 90 HOUSES AND HOTELS WERE DESTROYED

32. 130 CARS AND BOATS WERE ALSO LOST

38. WAKE UP WAKE UP

43. FLOOD MANAGEMENT

44. THE MOUTH OF THE EAST LYNN WAS WIDENED TO INCREASE CAPACITY AND ALLOW WATER TO QUICKLY PASS INTO THE BISTROL CHANNEL

45. WEST LYN HAS STRAIGHTENED TO INCREASE CHANNEL EFFICIENCY, IT HAS NOT BE REDIVERTED , INSTEAD ITS BEING ALLOWED TO FOLLOW ITS NATURAL COURSE

46. FLOODPLAIN ZONING WAS USED TO IDENTIFY AREAS AROUND THE RIVER MOST AT RISK FROM FLOODING. BUILDING RESTRICTIONS WERE PUT IN PLACE WITH AREAS CLOSE TO THE RIVER.

47. BRIDGES WERE MADE WIDER AND TALLER TO ALLOW FLOOD WATER TO TRAVEL QUICKLY BENEATH THEM.

48. EMBANKMENTS WERE BUILT BY THE RIVER TO INCREASE CHANNEL CAPACITY AND REDUCE THE LIKELIHOOD OF FLOODING

49. MORE TREES WERE PLANTED UPSTREAM IN THE SOURCE AREA TO TRY AND REDUCE INITIAL SURFACE RUNOFF THROUGH INTERCEPTION AND THE SOAKING UP OF WATER. TREE ROOTS ALSO HELP TO IMPROVE INFILTRATION BY OPENING UP THE SOIL AND SLOWING DOWN THE RATE OF WATER AT WHICH WATER REACHES THE GROUND.