Mechanisms Controlling Water‐Level Variations in the Middle Yangtze River Following the Operation of the Three Gorges Dam

Abstract

Half a century ago, Leopold (1956) predicted that dams would someday become so numerous on American rivers that they would be the primary factor controlling the characteristics of river channels. His prediction is becoming true for river systems worldwide, with 𝐴𝐴 𝐴 45,000 large dams (height 𝐴𝐴 𝐴 15 m) distributed over 140 countries (Ma et al., 2022;Syvitski et al., 2022). Dams are often designed to generate hydropower and mitigate floods (Li et al., 2022;Ma et al., 2022), but they also disrupt river continuity and induce drastic temporal and spatial alterations in river flow and sediment regimes (

Dune Development Dominates Flow Resistance Increase in a Large Dammed River

“…Based on the local geographical setting and channel patterns, the MYR can be divided into nine sub‐reaches, with a total length of ∼955 km ranging from Yichang to Hukou, connected to the floodplain‐type Dongting and Poyang Lakes (Figure 1a). The MYR was confirmed to be a subcritical unidirectional large alluvial river with a width of 1,552 m, a depth of 14 m, and a water surface slope of 5 × 10 −5 in bank‐full discharge (Hu, Li, et al., 2022). Field photos are shown in Figures 1b–1f.…”

“…However, the application of previous resistance calculation methods in the MYR has yielded unsatisfactory results (Hu, Li, et al., 2022). These issues can be attributed to two major reasons.…”

“…Given its impact on water levels and sediment transport, understanding flow resistance is vital for river dynamics, yet its direct field quantification remains elusive (de Lange et al., 2021; Hu, Li, et al., 2022). Previous studies have investigated the flow resistance in large rivers mainly through calculation methods based on flume experiments (Huang et al., 2004; Peterson & Peterson, 1988), numerical experiments (Lefebvre & Winter, 2016), and small rivers (Ferguson, 2021).…”

“…Furthermore, quantifying dune resistance in natural rivers often lacks simplicity, typically requiring complex mathematical and physical derivations or detailed parameter measurements (Valance et al., 2023; Cho & Nelson, 2024a, 2024b). Thus, a refined geomorphologic‐informed resistance calculation method, capturing large alluvial river dune adjustments, is essential for analyzing channel resistance's spatiotemporal dynamics and flood risk assessment (Hu, Li, et al., 2022).…”

Surface Water–Groundwater Transformation Patterns in the Jianghan Plain after the Impoundment of the Three Gorges Project and the Opening of the Yangtze-to-Hanjiang Water Transfer Project

“…The Jianghan Plain, formed by the alluvial deposits of the Yangtze River's main stream and the Hanjiang River Basin, is celebrated for a land of fish and rice; it also serves as a crucial source of China's commodity grain [14]. Scholars have focused on nitrogen, phosphorus, and arsenic in the water chemistry characteristics of the Jianghan Plain [15][16][17][18][19], groundwater hydrodynamic issues [20,21], the relationship characteristics of the rainfall, water sand, flow, and runoff of rivers and lakes in the Jianghan Plain region under climate change [22][23][24][25][26][27]. And there are studies related to the Jianghan Plain cascade reservoirs and watershed reservoir complex [28][29][30][31].…”