Less extreme and earlier outbursts of ice-dammed lakes since 1900.

Episodic failures of ice-dammed lakes have produced some of the largest floods in history, with disastrous consequences for communities in high mountains1-7. Yet, estimating changes in the activity of ice-dam failures through time remains controversial because of inconsistent regional flood databases. Here, by collating 1,569 ice-dam failures in six major mountain regions, we systematically assess trends in peak discharge, volume, annual timing and source elevation between 1900 and 2021. We show that extreme peak flows and volumes (10 per cent highest) have declined by about an order of magnitude over this period in five of the six regions, whereas median flood discharges have fallen less or have remained unchanged. Ice-dam floods worldwide today originate at higher elevations and happen about six weeks earlier in the year than in 1900. Individual ice-dammed lakes with repeated outbursts show similar negative trends in magnitude and earlier occurrence, although with only moderate correlation to glacier thinning8. We anticipate that ice dams will continue to fail in the near future, even as glaciers thin and recede. Yet widespread deglaciation, projected for nearly all regions by the end of the twenty-first century9, may bring most outburst activity to a halt.

Historic Yangtze flooding of 2020 tied to extreme Indian Ocean conditions.

Heavy monsoon rainfall ravaged a large swath of East Asia in summer 2020. Severe flooding of the Yangtze River displaced millions of residents in the midst of a historic public health crisis. This extreme rainy season was not anticipated from El Niño conditions. Using observations and model experiments, we show that the record strong Indian Ocean Dipole event in 2019 is an important contributor to the extreme Yangtze flooding of 2020. This Indian Ocean mode and a weak El Niño in the Pacific excite downwelling oceanic Rossby waves that propagate slowly westward south of the equator. At a mooring in the Southwest Indian Ocean, the thermocline deepens by a record 70 m in late 2019. The deepened thermocline helps sustain the Indian Ocean warming through the 2020 summer. The Indian Ocean warming forces an anomalous anticyclone in the lower troposphere over the Indo-Northwest Pacific region and intensifies the upper-level westerly jet over East Asia, leading to heavy summer rainfall in the Yangtze Basin. These coupled ocean-atmosphere processes beyond the equatorial Pacific provide predictability. Indeed, dynamic models initialized with observed ocean state predicted the heavy summer rainfall in the Yangtze Basin as early as April 2020.

Changing climate both increases and decreases European river floods.

Climate change has led to concerns about increasing river floods resulting from the greater water-holding capacity of a warmer atmosphere1. These concerns are reinforced by evidence of increasing economic losses associated with flooding in many parts of the world, including Europe2. Any changes in river floods would have lasting implications for the design of flood protection measures and flood risk zoning. However, existing studies have been unable to identify a consistent continental-scale climatic-change signal in flood discharge observations in Europe3, because of the limited spatial coverage and number of hydrometric stations. Here we demonstrate clear regional patterns of both increases and decreases in observed river flood discharges in the past five decades in Europe, which are manifestations of a changing climate. Our results-arising from the most complete database of European flooding so far-suggest that: increasing autumn and winter rainfall has resulted in increasing floods in northwestern Europe; decreasing precipitation and increasing evaporation have led to decreasing floods in medium and large catchments in southern Europe; and decreasing snow cover and snowmelt, resulting from warmer temperatures, have led to decreasing floods in eastern Europe. Regional flood discharge trends in Europe range from an increase of about 11 per cent per decade to a decrease of 23 per cent. Notwithstanding the spatial and temporal heterogeneity of the observational record, the flood changes identified here are broadly consistent with climate model projections for the next century4,5, suggesting that climate-driven changes are already happening and supporting calls for the consideration of climate change in flood risk management.

How long do floods throughout the millennium remain in the collective memory?

Is there some kind of historical memory and folk wisdom that ensures that a community remembers about very extreme phenomena, such as catastrophic floods, and learns to establish new settlements in safer locations? We tested a unique set of empirical data on 1293 settlements founded in the course of nine centuries, during which time seven extreme floods occurred. For a period of one generation after each flood, new settlements appeared in safer places. However, respect for floods waned in the second generation and new settlements were established closer to the river. We conclude that flood memory depends on living witnesses, and fades away already within two generations. Historical memory is not sufficient to protect human settlements from the consequences of rare catastrophic floods.

Nursing in the Midwestern Flood.

: Editor's note: From its first issue in 1900 through to the present day, AJN has unparalleled archives detailing nurses' work and lives over more than a century. These articles not only chronicle nursing's growth as a profession within the context of the events of the day, but they also reveal prevailing societal attitudes about women, health care, and human rights. Today's nursing school curricula rarely include nursing's history, but it's a history worth knowing. To this end, From the AJN Archives highlights articles selected to fit today's topics and times.This month's article appeared in the September 1943 issue, and reported on the spring flooding that had ravaged several midwestern states. Rebecca M. Pond of the Red Cross noted that during the floods, nurses worked in "hutments and barracks in [the] Army airport, unused factory buildings, college buildings, town and rural school houses, Boy Scout camps, abandoned CCC [Civilian Conservation Corps] camps, and an annex to a state hospital." The nursing care provided sounds like nursing in today's disaster shelters: providing health assessments, immunizations, and emergency care; maintaining isolation precautions where needed; monitoring prenatal women, infants, young children, and the elderly or ill; and supervising housekeeping and sanitation services.In recent years, the United States has experienced particularly severe flooding and other disasters precipitated by climate change. In this month's issue, Cara Cook and colleagues explore the many ways in which today's nurses can help to prevent (and not only ameliorate) the effects of a changing climate.

Fecal stanols show simultaneous flooding and seasonal precipitation change correlate with Cahokia's population decline.

A number of competing hypotheses, including hydroclimatic variations, environmental degradation and disturbance, and sociopolitical disintegration, have emerged to explain the dissolution of Cahokia, the largest prehistoric population center in the United States. Because it is likely that Cahokia's decline was precipitated by multiple factors, some environmental and some societal, a robust understanding of this phenomenon will require multiple lines of evidence along with a refined chronology. Here, we use fecal stanol data from Horseshoe Lake, Illinois, as a population proxy for Cahokia and the broader Horseshoe Lake watershed. We directly compare the fecal stanol data with oxygen stable-isotope and paleoenvironmental data from the same sediment cores to evaluate the role of flooding, drought, and environmental degradation in Cahokia's demographic decline and sociopolitical reorganization. We find that Mississippi River flooding and warm season droughts detrimental to agriculture occurred circa (ca.) 1150 CE and possibly generated significant stress for Cahokia's inhabitants. Our findings implicate climate change during the Medieval Climatic Anomaly to Little Ice Age transition as an important component of population and sociopolitical transformations at Cahokia, and demonstrate how climate transitions can simultaneously influence multiple environmental processes to produce significant challenges to society.

On the extraordinary winter flood episode over the North Atlantic Basin in 1936.

In this study, we analyze the linkage between atmosphere and ocean modes and winter flood variability over the 20th century based on long-term flow-discharge series, historical archives, and tree-ring records of past floods in the North Atlantic Basin (NAB). The most extreme winter floods occurred in 1936 and had strong impacts on either side of the Atlantic. We hypothesize that the joint effects of sea surface temperatures (SSTs) over the Atlantic and Pacific Oceans and the Arctic Oscillation (AO), which is closely related to the North Atlantic Oscillation, play a significant role when describing flood variability in North America and Europe since 1900. Statistical modeling supports the assumption that the response of flood anomalies over the NAB to AO phases is subsidiary of SST phases. Besides, we shed light on the extraordinarily winter flood of 1936 that was characterized by very high SSTs over both the Atlantic and Pacific (>98th percentile) and very low, negative values of AO (<1st percentile). This outstanding winter flood episode was most likely characterized by stratospheric polar vortex anomalies, which can usually be linked to an increased probability of storms in western and southwestern Europe and increased snowfall events in eastern North America. By assessing the flood anomalies over the NAB as a coupled AO and SST function, one could further the understanding of such large-scale events and presumably improve anticipation of future extreme flood occurrences.

Public Health Emergency Response Lessons Learned by Rapid Deployment Force 3, 2006-2016.

Following Hurricane Katrina, the uniformed US Public Health Service created an updated system through which its officers participated in emergency responses. The Rapid Deployment Force (RDF) concept, begun in 2006, involved five teams of officers with diverse clinical and public health skill sets organized into an incident command system led by a team commander. Each team can deploy within 12 hours, according to a defined but flexible schedule. The core RDF mission is to set up and provide care for up to 250 patients, primarily persons with chronic diseases or disabilities, in a temporary federal medical station. Between 2006 and 2016, the RDF 3 team deployed multiple times in response to natural disasters and public health emergencies. Notable responses included Hurricane Sandy in 2012, the unaccompanied children mission in 2014, and the Louisiana floods in 2016. Lessons learned from the RDF 3 experience include the need for both clinical and public health capacity, the value of having special mental health resources, the benefits of collaboration with other federal medical responders, and recognition of the large burden of chronic disease management issues following natural disasters.

Volcanic suppression of Nile summer flooding triggers revolt and constrains interstate conflict in ancient Egypt.

Volcanic eruptions provide tests of human and natural system sensitivity to abrupt shocks because their repeated occurrence allows the identification of systematic relationships in the presence of random variability. Here we show a suppression of Nile summer flooding via the radiative and dynamical impacts of explosive volcanism on the African monsoon, using climate model output, ice-core-based volcanic forcing data, Nilometer measurements, and ancient Egyptian writings. We then examine the response of Ptolemaic Egypt (305-30 BCE), one of the best-documented ancient superpowers, to volcanically induced Nile suppression. Eruptions are associated with revolt onset against elite rule, and the cessation of Ptolemaic state warfare with their great rival, the Seleukid Empire. Eruptions are also followed by socioeconomic stress with increased hereditary land sales, and the issuance of priestly decrees to reinforce elite authority. Ptolemaic vulnerability to volcanic eruptions offers a caution for all monsoon-dependent agricultural regions, presently including 70% of world population.The degree to which human societies have responded to past climatic changes remains unclear. Here, using a novel combination of approaches, the authors show how volcanically-induced suppression of Nile summer flooding led to societal unrest in Ptolemaic Egypt (305-30 BCE).

The social construction of disasters in the United States: A historical and cultural phenomenon.

INTRODUCTION: Societal risks from hazards are continually increasing. Each year, disasters cause thousands of deaths and cost billions of dollars. In the first half of 2011, the United States endured countless disasters-winter snowstorms in the Midwest and Northeast; severe tornadic weather in the Mississippi, Alabama, and Missouri; flash flooding in Nashville; flooding along the Mississippi River; an earthquake on the East Coast, wildfires in Texas, and Hurricane Irene. Fundamental disaster planning is regarded as an interdisciplinary approach to develop strategies and instituting policies concerned with phases of emergency management; as such, its needs are predicated on the identification of hazards and assessment of risks. PROBLEM: Even if the probability or intensity of risks to disasters remains fairly constant, population growth, alongside economic and infrastructural development, will unavoidably result in a concomitant increase of places prone to such events. One of the greatest barriers to emergency management efforts is the failure to fully grasp the socially and politically constructed meaning of disasters. PURPOSE: This article investigates the ways in which language has been used historically in the American lexicon to make sense of disasters in the United States in an effort to improve communal resiliency. Serving as both an idea and experience, the terminology used to convey our/the modern-day concept of disaster is a result of a cultural artifact, ie, a given time and specific place. METHODOLOGY: Tools such as Google Ngram Viewer and CASOS AutoMap are used to explore the penetration, duration, and change in disaster terminology among American English literature for more than 200 years, from 1800 to 2008, by quantifying written culture. FINDINGS: The language of disasters is an integral part of disaster response, as talking is the primary way that most people respond to and recover from disasters. The vast majority of people are not affected by any given disaster, and so it is through discussing a disaster that people make sense of it, respond, and react to it, and fit something that is overwhelming and beyond human control into the normal order of life.

Dispersion of radiocesium-contaminated bottom sediment caused by heavy rainfall in Joso City, Japan.

A large-scale heavy rainfall disaster occurred in Joso City, Japan, in September 2015, and one third of the city area (40 km2) was flooded by the Kinu River. Artificial radionuclides such as 134Cs and 137Cs were known to have accumulated in the river bottom sediment after their release in the 2011 Fukushima Dai-ichi Nuclear Power Plant accident. It was thought that these radionuclides might have been dispersed by the rainfall disaster. A car-borne survey of absorbed dose rate in air had been made by the authors in Joso City in August 2015. Then, the present study made a second car-borne survey in October 2015, to evaluate changes in the rate after the rainfall disaster. The absorbed dose rate in air and the standard deviation (range) measured in the flooded areas of Joso City after the disaster were 68 ± 9 nGy h-1 (39-98 nGy h-1), which was 10% higher than the rate before it. Additionally, higher dose rates (> 60 nGy h-1) were observed for the flooded areas after the disaster; furthermore, up to 886 Bq kg-1 of activity concentration from 134Cs and 137Cs was observed in these flooded areas, and this was 11 times higher than the activity concentration before the disaster. These results suggested the dispersion of artificial radionuclides accumulated in the bottom sediment of the Kinu River after the Fukushima Daiichi Nuclear Power Plant accident occurred by the heavy rainfall disaster.

Analysis of Risk and Burden of Dysentery Associated with Floods from 2004 to 2010 in Nanning, China.

This study aimed to examine the association between floods and the morbidity of dysentery and to quantify the burden of dysentery due to floods in Nanning, China. A generalized additive mixed model was conducted to assess the relationship between monthly morbidity of dysentery and floods from 2004 to 2010. The years lived with disability (YLDs) of dysentery attributable to floods were then estimated based on the WHO framework of the burden of disease study for calculating the potential impact fraction. The relative risk (RR) of floods on the morbidity of dysentery was 1.44 (95% confidence interval [CI] = 1.18-1.75). The models suggest that a potential 1-day rise in flood duration may lead to 8% (RR = 1.08, 95% CI = 1.04-1.12) increase in the morbidity of dysentery. The average attributable YLD per 1,000 of dysentery caused by floods were 0.013 in males, 0.005 in females, and 0.009 in persons. Our study confirms that floods have significantly increased the risk and the burden of dysentery in the study area. Public health action should be taken to prevent and control the potential risk of dysentery after floods. Vulnerable groups such as males and children should be paid more attention.

Leibniz's Observations on Hydrology: An Unpublished Letter on the Great Lombardy Flood of 1705.

Although the historical reputation of Gottfried Wilhelm Leibniz (1646-1716) largely rests on his philosophical and mathematical work, it is widely known that he made important contributions to many of the emerging but still inchoate branches of natural science of his day. Among the many scientific papers Leibniz published during his lifetime are ones on the nascent science we now know as hydrology. While Leibniz's other scientific work has become of increasing interest to scholars in recent years, his thinking about hydrology has been neglected, despite being relatively broad in extent, including as it does papers on the 'raising of vapours' and the formation of ice, as well as the separation of salt and fresh water. That list can now be extended still further following the discovery of a previously unpublished letter of Leibniz's on the causes of the devastating Lombardy flood of October and November 1705. This letter, which will be the focus of our paper, reveals the depth of Leibniz's understanding of key hydrological processes. In it, he considers various mechanisms for the flood, such as heavy rains on high ground, underwater earthquakes, and a mountain collapse. Over the course of the paper we examine each of these mechanisms in depth, and show that Leibniz was in the vanguard of hydrological thinking. We also show that the letter contains one of the first scholarly attempts to apply aspects of the still-forming notion of the hydrological cycle to account for a flood event.

Flooding and emergency room visits for gastrointestinal illness in Massachusetts: a case-crossover study.

INTRODUCTION: Floods and other severe weather events are anticipated to increase as a result of global climate change. Floods can lead to outbreaks of gastroenteritis and other infectious diseases due to disruption of sewage and water infrastructure and impacts on sanitation and hygiene. Floods have also been indirectly associated with outbreaks through population displacement and crowding. METHODS: We conducted a case-crossover study to investigate the association between flooding and emergency room visits for gastrointestinal illness (ER-GI) in Massachusetts for the years 2003 through 2007. We obtained ER-GI visits from the State of Massachusetts and records of floods from the National Oceanic and Atmospheric Association's Storm Events Database. ER-GI visits were considered exposed if a flood occurred in the town of residence within three hazard periods of the visit: 0-4 days; 5-9 days; and 10-14 days. A time-stratified bi-directional design was used for control selection, matching on day of the week with two weeks lead or lag time from the ER-GI visit. Fixed effect logistic regression models were used to estimate the risk of ER-GI visits following the flood. RESULTS AND CONCLUSIONS: A total of 270,457 ER-GI visits and 129 floods occurred in Massachusetts over the study period. Across all counties, flooding was associated with an increased risk for ER-GI in the 0-4 day period after flooding (Odds Ratio: 1.08; 95% Confidence Interval: 1.03-1.12); but not the 5-9 days (Odds Ratio: 0.995; 95% Confidence Interval: 0.955-1.04) or the 10-14 days after (Odds Ratio: 0.966, 95% Confidence Interval: 0.927-1.01). Similar results were observed for different definitions of ER-GI. The effect differed across counties, suggesting local differences in the risk and impact of flooding. Statewide, across the study period, an estimated 7% of ER-GI visits in the 0-4 days after a flood event were attributable to flooding.

Flooding and the framing of risk in British broadsheets, 1985-2010.

Our analysis of 2707 news stories explores the framing of flooding in Britain over the past quarter century and the displacement of a once dominant understanding of flooding as an agricultural problem of land drainage by the contemporary concern for its urban impacts, particularly to homes and property. We document dramatic changes in the volume and variety of reporting about flooding since 2000 as the risks of flooding have become more salient, the informal 'Gentlemen's Agreement' between government and private insurers has broken down, and flood management subjected to greater public scrutiny. While the historic reliance on private insurance remains largely unchallenged, we show that other aspects of flood hazard management are now topics of active political debate to which the looming threat of climate change adds both urgency and exculpatory excuses for poor performance. We conclude by reflecting on the significance of the case for grand theories of neoliberalisation and governmentality.