A 2000-year documentary record of levee breaches on the lower Yellow River and their relationship with climate changes and human activities

Abstract

The Yellow River floodplain represents a fertile landmass that contributes significantly to human welfare and thus has been colloquially known as the birthplace of Chinese civilization. The sediment-laden nature of the Yellow River gave rise to a super-elevated channel belt, which is prone to failure particularly in the summer months when excessive precipitation occurs, resulting in cataclysmic floods traditionally regarded as “China’s Sorrow.” Therefore, a deeper understanding of levee breach frequency in this area is especially important for the assessment of socio-economic risk of levee breaches associated with future climate changes. To better understand the nature, evolution, and driving mechanisms of levee breaches on the lower Yellow River, it is necessary to place the instrumental data within a longer time framework. Here, we retrieve past information about levee breaches on the lower Yellow River since AD 11 from various documentary sources such as official histories of China. We evaluated each line of descriptions and narratives about the location, timing, and nature of each event in these documents, ending up with a detailed timeline of levee breaches on the lower Yellow River during the last 2000 years on an annual time scale. Our results reveal remarkable variations in the frequency of levee breaches superimposed on a long-term increasing trend. In addition to climate changes, the iterative embankment-siltation-breaching process caused a feedback: more breaches result in much more channel siltation, which in turn leads to even more breaches. The enhanced farming in the Loess Plateau played a pivotal role in the formation and operation of this positive feedback. Our findings may not only help improve the assessment of socio-economic risk of levee breaches associated with future climate changes, but also provide consulting information for hydraulic engineering and infrastructural designs in the lower Yellow river area.

Spatio-temporal variations of the major meteorological disasters and its response to climate change in Henan Province during the past two millennia

“…After the end of the LIA, a warming trend occurred that lasted into the 20C WP, and within the 20C WP, the globally averaged surface temperatures over land and ocean showed a linear warming trend of 0.85 °C from 1880 to 2012 CE ( Intergovernmental Panel on Climate Change (IPCC), 2014 ; Zhou et al, 2021 ). According to previous studies, the increased frequency and severity of meteorological disasters can be found during the 20C WP ( Shi, Cui & Tian, 2020 ; Li et al, 2021b ; Li, Li & Zhang, 2020 ; Xing et al, 2020 ; Zhou et al, 2021 ), and our record also indicated the major meteorological disasters occurred frequently since 1911 CE ( Figs. 3 and 4B ).…”

“…4C ). Previous studies have shown that the temperature changes in the Henan Province were highly consistent with those in most regions of China, whether it is the warming trend in the 20th century or the century-scale warming and cooling phases in the past 2,000 years ( Ge et al, 2016 ; Zheng et al, 2014a ; Li et al, 2021b ). Among them: during the Han Dynasty (100 BCE–200 CE), Sun and Tang Dynasties (550–850 CE), Song and Yuan Dynasties (950–1300 CE) and the 20th century, the climate was relatively warm and other periods were relatively cold ( Figs.…”

“…2 and 3 ). Meanwhile, due to its location in the middle and lower of the Yellow River, the anthropogenic deforestation and agricultural expansion could also enhance the soil erosion and increase sedimentation rate in the channel, which can easily make the levee prone to breaching and cause widespread flooding ( Li, Li & Zhang, 2020 ; Li et al, 2021b ). Our results also proved the flood disaster occurred frequently over the past 2,000 years and increased significantly with the increase in population ( Fig.…”

“…Many scholars have studied the climate change in China over the past 2,000 years and found that the climate change has a great influence on the occurrence of the meteorological disasters in the millennia scale ( Wu et al, 2018a ; Lee et al, 2017 ; Zheng, Wen & Fang, 2020 ; Li, Li & Zhang, 2020 ; Ge et al, 2016 ; Gao, Yin & Li, 2019 ; Hao et al, 2017 ; Li et al, 2021b ). To better understand the impact of climate changes on meteorological disaster in the Henan Province, the major meteorological disaster record was compared with the reconstructed temperature anomaly in east China and North Hemisphere temperatures ( Figs.…”

“…Although the occurrence of the meteorological disasters was less in this period, it demonstrates variations on centennial time scales ( Figs. 3 and 4B ) and the timescale of this variability may be determined by patterns of climate ( Li et al, 2021b ). Before 950 CE, Northern Hemisphere temperature mainly experienced two periods: the Roman Warm Period and the Dark Ages Cold Period, but the temperature phases in east China showed opposite trends with northern hemisphere ( Figs.…”