Tuesday, 11 July 2017

Natural Disasters and Family Misfortunes 6: Floods

Natural events that will come to mind for most readers, and that many may have been affected by, are floods – whether of the rapid overnight or slow-developing over weeks type. Floods are normal things; they happen every year and in almost every river valley. Sometimes they are minor events; other times they are devastating – to people and communities. But they have been part of natural phenomena forever.

Historically most farming communities have benefited by river flooding that brought moisture and deposited rich new sediment across fields.

Seared into human memory, though, are the major, disastrous varieties, when infrastructure and human lives were lost on a grand scale. For family historians, again, such events may have ended up forcing people to migrate or left chaos among the lives of survivors.

In any year, as far back as records exist, one may find descriptions of floods that disrupted communities and took lives.

Naturally occurring floods are almost always a result of major storms. Exceptions are those that arrive as tsunamis (see blog post of 20 June 2017). Along shorelines floods may arise from sea surges, those also produced by storms in the open ocean. Every continent has had its share of large-scale flooding. Those with very extensive river systems or large collection areas may suffer through floods extending over vast areas.

In Europe the greatest disasters from flooding resulting from storm surges, coming ashore mostly from the North Sea. The 1287 St. Lucia flood is reported to have killed 50,000 to 80,000 people in the Netherlands and northern Germany. What had been a large fresh water lake surrounded by farming communities and fronted by barrier islands and peat swamps was turned into an extension of the North Sea – the Zuiderzee. There were undoubtedly many similar floods in the region as sea level rose following the last major ice age. There would be many more such storms in succeeding centuries, particularly during the Little Ice Age (AD 1315-1850), until residents learned to mostly control them with dams, dykes and surge barriers.

A major flood hit north-central England in November 1771. A storm broke over the highlands of the Pennines with heavy rain for several days combined with melting of snow in the highest reaches. All rivers flowing out of the region, to the north, south, east and west overflowed their banks, from the source areas to the tidal inlets, over 60 miles in the cases of the Tyne, Tees and Wear Rivers.

In many areas the water arrived in flash-floods with water levels rising over the eaves of houses within minutes. Buildings of all types, ships tied up along the wharves, goods left lying on quays, farm animals and implements and, of course, people were swept away in the raging currents. Bridges, including the 500-year old Tyne Bridge at Newcastle, were unable to withstand the onslaught of water and were destroyed. In some areas, water levels in the lower reaches were over 12 feet above normal, high spring tides.
Gaps through Pennine Mountains; Topographic Map of the UK; Mercator projection
Etching of Tyne Bridge at Newcastle after the 1771 flood; source – Newcastle Libraries
In North America, the Mississippi River and all of its major tributaries have consistently inundated lands adjacent to their water courses. They are not called floodplains for no reason!

The drainage area for the Mississippi encompasses 1,245,000 square miles. From its source in Minnesota, it takes on the flow from 10 major tributaries, eventually dumping millions of tons of sediment into its delta area in the Gulf of Mexico. During frequent floods it also delivers substantial volumes of new soil to surrounding farmland in all the river valleys.
Mississippi River tributaries, from USGS data
There have been dozens of major flood episodes in the Mississippi basin, from upriver storms, hurricanes arriving from the Gulf of Mexico or exceptional snow melt from the Rocky Mountains and runoff in the tributaries coming from there. The lower Mississippi always seemed to get the brunt of the excess water. The earliest report of a flood is from 1543 when Spanish explorer Hernando DeSoto arrived at the confluence of the Mississippi and Arkansas Rivers.

The most disastrous flood in recorded history in the United States happened in 1927 as exceptional amounts of rain fell along many of the major tributaries of the central part of the basin. Over 27,000 acres were covered with water, with depths up to 30 feet, primarily in the states of Arkansas, Mississippi and Louisiana. More than 700,000 people were left homeless; 500 people died. Many of the displaced, particularly those in the labouring class, gave up on the region and migrated to northern and Midwestern cities. Following this event, the US Congress passed the Flood Control Act of 1928, charging the US Army Corps of Engineers with the task of establishing controls on the flow and flooding of the river system.
1927 Mississippi River flooded areas - Records of the Coast and Geodetic Survey, RG; source – Public Domain
In China, major rivers have also experienced widespread flooding over the centuries. The best documented are, of course, the most recent. In 1931, a combination of melting of large snow accumulations in the western mountain ranges, exceptional and heavy rain in the central regions and cyclone activity from the eastern ocean saw substantial more volumes of water in the system than normal. In addition, “[e]xcessive deforestation, wetland reclamation, and the over-extension of river dyke networks transformed regular flood pulses, which were an integral feature of the fluvial ecosystem, into destructive inundations, which wrought chaos upon human communities.” (DisasterHistory.org)
Great flood at Gaoyou, Jingsu province; source - The Great Floods of 1931 at Gaoyou website
Rebuilding of dykes following the disastrous flooding in 1931; Sampans transport the soil to Gaoyou Dikes on the Grand Canal, Jiangsu Province. Source - The Great Floods of 1931 at Gaoyou website
The cumulative causes, both natural and manmade, resulted in a devastating event that affected 52 million people with two million deaths. Following the event many programs were initiated to build new and better dyke systems and institute flood control measures. These were built largely from manual labour of thousands of workers.

Such large-scale floods are not unique to modern times. No doubt all river systems have seen excessive precipitation that resulted in widespread inundation. Where no people were around
to witness the events, they would not be considered as disasters. Today most regions are highly populated meaning that even minor flooding can do significant damage and affect many communities.

Family historians may well find some of their ancestors were affected by floods. Such evidence can be found in newspapers of the day, written up in parish or estate accounts or detailed in many books and other publications.

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