Reproducibility package for "Damming the delta: cross-border attribution of coastal-delta sediment starvation for transboundary river governance"

Abstract

Reproducibility package for "Damming the delta: cross-border attribution of coastal-delta sediment starvation for transboundary river governance" (Yiran Li), revision 1 (R1) of the manuscript under review at the Journal of Hydrology: Regional Studies. This version supersedes version 1, which accompanied the original submission. The package contains the analysis code, the derived data tables and the figures underlying the paper, which presents a global source–receptor accounting of cross-border delta sediment starvation. Local sediment production is routed along the HydroBASINS river network; each dam's trapping is computed from its Brune efficiency and regulated-flow share; large natural lakes retain sediment with and without dams; natural loads are anchored to observed pre-dam values (39 rivers) or to the pristine loads of the Nienhuis et al. (2020) delta inventory; and each delta's dam-induced deficit is split into a domestic and a cross-border part and attributed to the upstream countries responsible. Key results (R1): dams withhold about 5,100 Mt yr⁻¹ of sediment from the world's inventoried deltas, of which about 1,130 Mt yr⁻¹ (22.1%) is withheld by dams in another country; 46 countries are net downstream bearers (25 of them bearing at least 1 Mt yr⁻¹); about 156 million people live on national delta parts that have lost at least a tenth of their sediment supply, mostly to foreign dams, 87% of them in Bangladesh and Egypt. Leading upstream sources: India, the United States, China, Ethiopia and Brazil. Contents: the analysis scripts (sediment_routing.py and the revision scripts run by run_all_r1.sh), the builders of the manuscript, Supplementary Material and response letter (build_all.sh), all derived CSV and JSON tables, Figures 1–5 and the graphical abstract. README_R1.md documents the input data, the run order, the method and all changes from version 1. A clean-room run from the public raw inputs (HydroBASINS, BasinATLAS, Global Dam Watch, the GlobalDeltaData of Nienhuis et al., the delta extents of Edmonds et al., the WorldPop 2020 grid, Natural Earth and World Bank GDP) reproduces every derived table byte for byte. The reviewer reports are confidential and are not included. No generative-AI tools were used to produce any figure or graphical artwork; all figures are data plots generated by the included code.