The 1931 Yangtze River Flood

The process in which an overflow of water submerges land that is usually dry is termed flooding. The majority of river floods are relevant to the quantity and distribution of rainfall within the drainage basin, the speed at which rainfall infiltrates the earth, and how quickly surface runoff reaches the river (Keller, 259). In addition, the amount of water already absorbed by the drainage plays an important role in the probability of flooding, as soil can often act as a wet sponge. If a considerable amount of rain falls on an already saturated basin, the soil cannot hold any more moisture which causes flooding (Keller, 259). In mountainous regions such as the Yangtze River Basin, floods are more common during early spring and midwinter thaws (Keller, 259). At the most basic level, the 1931 Yangtze floods can be explained by the combination of excessive snow melting and an unpredictable amount of rain.

The Yangtze, or Chang Jiang River is the longest river that courses through Asia, and is the third longest river in the world, with a length of 3,915 miles (6,300 km). The name Yangtze is known mainly by people living in the West, deriving from the ancient fiefdom ruled by Yang (Muranov, 2020). Chang Jiang, the common name used to identify the Yangtze River by the Chinese people, translates to "Long River." Important cities along the Yangtze include Shanghai, Luzhou, Chongqing and Wuhan (Courtney, 2018). From the Yangtze's source at the Tibetan Plateau, the river travels south for hundreds of miles through steep mountains and valleys, where it emerges on the Yunnan-Guizhou (Yungi) Plateau. From the Yungi Plateau, the Yangtze River flows in a mostly eastward direction, where it empties into the East China Sea.

The Yangtze River Basin has been the heart of Chinese settlement for millenia. 45 million years ago, the Indian and Eurasian tectonic plates collided, raising the Himalayas and forming the Tibetan-Qinghai Plateau (Courtney, 2018). As water drained from the newly formed highlands, it carved the basins of many of China's rivers, including the Yangtze. Its basin extends 2,000 miles from west to east, and more than 600 miles from north to south, making the area ideal for settlement, agriculture, drinking water and commerce (Muranov, 2020).

Long before humans inhabited the Yangtze River Basin, the region already experienced natural flooding events. Much of the basin has large depressions set in mountainous valleys, which creates "bottlenecks" in the river's flow (Courtney, 2018). As a result, water accumulates easily in these areas and is slow to discharge. The streamflow of the Yangtze fluctuates with the seasons, and varies between the three main sections of the river: the upper Yangtze, middle Yangtze, and lower Yangtze. Two monsoon systems, the East Asian and South Asian monsoons influence the water level along the Yangtze. The middle portion of the Yangtze sits between these two systems; the South Asian monsoon affects the amount of precipitation in the upper Yangtze and the East Asian monsoon influences the level of rainfall within the entire basin (Courtney, 2018).

The basin experiences on average three annual surges of precipitation and high-water, one in the spring, summer and fall (Courtney, 2018). The water is at its lowest during the winter, when precipitation falls in the form of snow. This snow accumulates near the Tibetan Plateau and remains in these frozen reservoirs through winter, until they melt in the spring, "infusing rivers with large volumes of water at the same time that the region experiences the first of its three annual waves of precipitation" (Courtney, 2018). Heaviest rainfall occurs in the summer, when cold fronts collide with humid air from the subtropics, and is the when the Yangtze River Basin is most vulnerable to flooding (Courtney, 2018). The quantity of water stored in these frozen reservoirs to the northwest, combined with the amount of annual precipitation within the Yangtze River Basin, makes flooding a relatively normal event in south China.

The first inhabitants of the Yangtze River floodplain took advantage of seasonal flooding. Flooding helps with seed dispersal, because as water rises above the riverbank and throughout the floodplain, seeds can travel farther than their normal range. As a result, seasonal flooding boosts biodiversity and pushes out invasive species, making it an "essential recharge mechanism" for the Yangtze River Basin (Courtney, 2018). Early settlers of this area were drawn to a semi-aquatic grass known as wild rice, which soon became essential to the Chinese economy (Courtney, 2018). Cultivation of wild rice increased with settlement, and as farmers domesticated the plant to have an entire succession mature at the same rate, wild rice's root structure became less flood resistant. Early rice farmers "practiced flood-recession agriculture, planting their crops on mud banks after the annual inundation had abated," which allows crops to take advantage of water left behind after flooding, reducing the risk of crop failure (Courtney, 2018).

Overtime, management of the Yangtze changed. Rather than working with or around the region's natural flood patterns, settlers began to modify agriculture and settlement, interfering with the Yangtze's natural flood patterns. By 2500 B.C, rice farmers began planting rice on bonded terraces known as paddy fields, essentially creating artificial wetlands (Courtney, 2018). Rice paddies along the Yangtze soon supported the diet of nearly the entire Chinese population. Sedentary rice farming allows farmers to settle in one area, but also involves a greater investment and generates additional flood risk. During the era of flood recession agriculture, farmers could swiftly pack up their belongings and flee if their home was at risk of flooding (Courtney, 2018). Modern rice farmers who modify their landscape risk losing serious investments of time and money if they were to abandon their homes during a flood.

Nearly one third of the nation's population resided within the Yangtze River Basin in 1931; and as a result, forests and wetlands were destroyed, and land close to the river was overused (Justin, 2019). Being one of the most heavily populated areas of the world, many people took advantage of the river’s water access and created settlements and agricultural fields. The river's natural functions were inevitably exploited via installing dams, dredging and dumping pollutants along with other waste materials into the water (Li, 2019). Prior to these anthropogenic inputs, the Yangtze River was able to maintain its flow during periods of heavy rainfall (Li, 2019). However, as populations along the river increased, so did the area's vulnerability to flooding. As people continued to intervene with the river's flow, "floods were no longer determined solely by climate and hydrology but also by economics and politics" (Courtney, 2018).

The 1931 Yangtze River floods are considered to be one of the most extensive and damaging natural disasters of the twentieth century. As many as 50 million people were indirectly affected by the floods, and an estimated 2 million people died in the months that followed (Alejandrino, 2019). Temperatures during the winter of 1930 were particularly cold, causing large deposits of snow to accumulate in the highlands of western China (Courtney, 2018). As temperatures rose with the spring in 1931, these snow deposits melted, and as a result, the middle of the Yangtze was overwhelmed with water. In April of 1931, the basin along the Yangtze experienced an unusual increase in precipitation. Excessive snowmelt and unusually high levels of precipitation during the spring months rose the Yangtze River Basin's water table to an already dangerously high level (Courtney, 2018). Seven devastating storms swept down the valley rapidly throughout July; "as much rain fell in one month that would be expected in one and a half years" (Courtney, 2018). The Chinese people had a long and tumultuous journey ahead of them to restore the Yangtze plains.

The 1931 Yangtze floods inundated approximately 180,000 square kilometers, an area equal to the size of New York, New Jersey and Connecticut combined. The flood area extended as far south to Guangdong, as far north as Manchuria and as far west as Sichuan (Courtney, 2018). 8 out of China's 23 provinces were severely affected, including the Yellow River and Grand Canal. Directly after the floods, as much as a tenth of the Chinese population was displaces, their homes completely under water. As flood waves swept across the landscape, hundreds of thousands of people died from drowning. The dykes that surrounded the industrious city of Wuhan collapsed, causing the water being held back from the flood wall to pour into the city at alarming speeds (Courtney, 2018). The force of the floods tore down buildings and concrete structures, which also added to the number of casualties (Courtney, 2018).

On August 19th, 1931, water levels exceeded 16 meters, drowning 200,000 people (Justin, 2019). The immediate effects of the Yangtze floods transformed the plains of the Yangtze River Basin into an area resembling a Great Lake, with nothing but water as far as the eye can see. Streets turned into canals, and people were forced to squeeze onto any dry land available. Sampan fisherman began taxying local Wuhan refugees to safety for an expensive price; those who couldn't afford the fare used whatever buoyant debris they could find, including broken down doors and inverted coffins (Courtney, 2018). The floods caused entire cities to lose power, making nights completely black. Because the streets were so deeply filled with water, policing was proved to become continuously difficult. One morning, a large cargo vessel carrying debris sailed into the Texaco oil depository, "causing a huge fire that was too hot for the fire brigade to approach" (Courtney, 2018). These fires lasted for three days, and provided the only source of light during the night for refugees.

While the immediate effects of the floods were disastrous, the secondary impacts were devastating. The floods completed washed away the region's rice paddies and agricultural fields, making an already impoverished nation more at risk of famine (Courtney, 2018, 4) In addition, the severity of the flood made a winter harvest impossible, proving starvation to be inevitable. Airports were forced to close, along with telegraphs and telephones. Not all railways were flooded, but the mass amount of refugees that took shelter along their tracks prevented aid supplies from entering Wuhan (Courtney, 2018). As a result, millions of people were left without reliable access to food, clean water, shelter and transportation.

"Words can hardly depict the feelings of oppression and poignant agony which filled me when I witnessed with my own eyes the scenes of death and desolation, of the excruciating sufferings of the injured and famished, and of those living torn asunder from their friends and relatives." - Chiang Kai-shek

As the people of China and Wuhan starved, the immune system of refugees became increasingly vulnerable, leading to the greatest cause of death in relation to the floods: disease. Sewage systems empties their way into cities, forcing citizens into a critical health crisis (Alejandrino, 2019). The waters that flooded the streets of Wuhan served as transportation, shelter, a source of food, and a facility to use the restroom. Combining all these activities into one area, in addition to the damage done to both the people and the city, created an environment perfect for the spread of disease. Dysentery, cholera and other waterborne illnesses began to spread across dense refugee settlements as a result to sanitation failure and pollution (Courtney, 2018). "More people succumbed to disease than from drowning or starvation," especially the poor who could not afford any of the basic needs to survival (Alejandrino, 2019).

The Chinese people were not left helpless to this natural disaster. In business communities like Wuhan, the people raised a substantial amount of money to fund aid projects, including the wooden walkway pictured above, showing refugees traveling above the flooded streets on makeshift bridges (Courtney, 2018). Refugees fished within the city's flooded waters, risking food-borne diseases because of starvation. In addition, the people of Wuhan set up multiple rice porridge kitchens to feed the starving, distributed boiling water for clean drinking and sanitation as well as the Buddhist monks, who turned their temples into refugee camps (Courtney, 2018). In rural areas, where farmers lost their rice crop and were too far away from urban centers to receive federal aid, refugees foraged for whatever they could. Rice paddies were lost, but aquatic plants like lotus, water chestnuts and wild rice thrived (Courtney, 2018). While it seems like the majority of China's resources were destroyed, many of the Chinese people were able to share resources and survive.

In addition to the foragable aquatic plants that refugees survived from, a multitude of plant and animal species benefitted from the Yangtze floods. Reed grass is both a sturdy and flood-resistant plant species, and was found in abundance along the shoreline of flooded riverbanks (Courtney, 2018). Refugees heavily harvested this plant to create shelter, as pictured above. Species of mosquitoes and water snails took advantage of their newly expanded ecological niche, spreading disease carrying bacteria. As a result, thousands of refugees died from epidemics of malaria and schistosomiasis (Courtney, 2018). Survival of the Yangtze floods strongly corresponded to the fortune of resources available, along with avoiding natural enemies.

The Chinese government did not play as important of a role in immediate aid of the 1931 Yangtze Floods. The cause of the flood can be explained extensive rain and snowmelt in short period of time, yet is does not explain the poor disaster response. At the time when rains poured over the nation, the Chinese government was battling political instability due to multiple wars and rebellions (Justin, 2019). Government programs responsible for managing river use were no longer a priority, causing the wetlands and riverbanks to become overused. The dikes and dams built to protect settlements were also poorly constructed and managed, making a flooding event an inevitable natural disaster (Justin, 2019). It took months for the government to send wheat and vaccines to refugees resided within the cities (Courtney, 2020). In addition, the Chinese government did little to stop the tension forming between the poor, wealthy and military. Military officials declared martial law, executing any refugee suspected of looting or other suspicious activities (Courtney, 2020). While the rich sat in semi-spacious camps with a reliable access to food, they forced the poor to work in labor camps in order to receive daily rations.

Much of the damage caused by the 1931 Yangtze River floods could have been avoided if flood control measures were followed closely. At the time of the floods, most of China's resources were being put towards funding a civil war, therefore sediment built along the river's bank and the Yangtze was inevitably neglected (History, 2009). In response to the flood, the Chinese government created the National Flood Relief Commission. Charity poured in from across the world to help with flood relief, with countries in Southeast Asia being particularly generous (Wikipedia, 2021). Once Japan invaded Manchuria in north eastern China during the autumn of 1931, flood relief efforts became much more difficult. Eventually, China was able to secure a large loan of wheat and flour from the United States which helped with food shortages. The Chinese Civil War and war with Japan made flood mitigation along the Yangtze extremely difficult, and so the government only managed to construct smaller dams and levees along the river. These proved to be ineffective during the destructive floods of 1954 and 1998 (Muranov, 2020).

As China became more politically stable by the end of the 20th century, they began the construction of the Three Gorges Dam along the Yangtze near the city of Yichang in Hubei Province (Britannica, 2020). When the dam's construction began in 1994, it was the largest engineering project in China; when construction finished in 2006, the Three Gorges Dam was the largest dam structure in the world. In addition to mitigating immense amount of flood damage, the dam also produces a great amount of hydroelectric power with the support of 32 turbine generators (Britannica, 2020). Combined with two additional generators, the dam can generate up to 22,500 megawatts of electricity, making it the most productive dam in the world (Britannica, 2020). At the present, water levels within the Three Gorges Dam are nearing full capacity, making the dam's long term effects questionable. For now, however, the dam has proven to be effective in protecting settlements along the Yangtze and cities like Wuhan from extensive flood damage.

As rained poured across southern China for months, the resulting floods affected a tenth of the nation. Millions of people were left without homes, food, employment, proper sanitation and safety. An already divided nation became increasingly torn, resulting in the poor and elderly suffering the most. No city was worse affected than Wuhan, where life was practically shut down. The flood received a great amount of attention and international aid at the time of the event, yet the 1931 Yangtze Floods seem to have been forgotten in current academia.

References:

“1931 China Floods.” Wikipedia, Wikimedia Foundation, 10 May 2021, en.wikipedia.org/wiki/1931_China_floods#Government_reactions. 

Alejandrino, Clark L. “The Nature of Disaster in China: The 1931 Yangzi River Flood by Chris Courtney.” Twentieth-Century China, vol. 44, no. 1, 2019, doi:10.1353/tcc.2019.0008. 

Britannica, The Editors of Encyclopaedia. "Three Gorges Dam". Encyclopedia Britannica, 28 May. 2020, https://www.britannica.com/topic/Three-Gorges-Dam. Accessed 11 May 2021.

Courtney, Chris. “Picturing Disaster: The 1931 Wuhan Flood.” China Dialogue, 2 Nov. 2020, chinadialogue.net/en/cities/10811-picturing-disaster-the-1931-wuhan-flood/. 

Courtney, Chris. The Nature of Disaster in China: The 1931 Yangzi River Flood. Cambridge University Press, 2018. 

Justin. “The Chinese Floods of 1931.” Globalenergynewscom, 4 July 2019, globalenergy-news.com/the-chinese-floods-of-1931/. 

Keller, Edward A., et al. Natural Hazards: Earth's Processes as Hazards, Disasters, and Catastrophes. Routledge, 2019. 

Li, Lillian M. “The Nature of Disaster in China: The 1931 Yangzi River Flood. By Chris Courtney (New York, Cambridge University Press, 2018) 310 Pp. $99.99.” The Journal of Interdisciplinary History, vol. 50, no. 2, 2019, pp. 310–311., doi:10.1162/jinh_r_01437. 

Muranov, Aleksandr Pavlovich. “Yangtze River.” Encyclopædia Britannica, Encyclopædia Britannica, Inc., 10 Nov. 2020, www.britannica.com/place/Yangtze-River. 

“Yangtze River Peaks in China.” History.com, A&E Television Networks, 13 Nov. 2009, www.history.com/this-day-in-history/yangtze-river-peaks-in-china.