Assessing Chinese flood protection and its social divergence

Abstract

Abstract. China is one of the most flood-prone countries, and development within floodplains is intensive. However, flood protection levels (FPL) across the country are unknown, hampering the present assertive efforts on flood risk management. Based on the flood-protection prescriptions contained in the national flood policies, this paper develops a FPL dataset of China and investigates how China should be protected accordingly and the divergent protections between demographic groups. The dataset agrees with local flood protection plans in 34 of archived 51 counties, validating the policy-based FPLs as a reliable proxy for actual FPLs. The FPLs are much higher than that in the previous global dataset, suggesting Chinese flood risk may have been overestimated. High FPLs (≥ 50-year return period) are seen in 282 or only 12.6 % of the evaluated counties, but with a majority (55.1 %) of the total exposed population. However, the low-FPL counties (

A global open-source database of flood-protection levees on river deltas (openDELvE)

“…Data on levees can help to better understand humanlandscape interactions (Werner and McNamara, 2007;Wang et al, 2021). One of these interactions is the so-called levee effect, defined by Gilbert White in 1947, whereby levee building creates an excessive sense of security, which leads to increased development and increased flood exposure (Hutton et al, 2019).…”

“…Levees have been constructed to mitigate flood risk and direct water flows throughout human civilization. Recorded building of levees along the River Nile in Egypt began around 4600 BP (Westermann, 1919), which indicates the innate link between the settlement of coastal populations and the development of levees. Modern materials and engineering concepts have altered the overall appearance and effectiveness of levees, but the basic principle has remained the same for millennia.…”