Data and R Code for "Beyond Peak-Centered Sampling: Hydrograph-Phase Diagnosis Improves Storm-Event Methylmercury Monitoring"

This deposit contains the event-scale mercury data and R code supporting the article “Beyond Peak-Centered Sampling: Hydrograph-Phase Diagnosis Improves Storm-Event Methylmercury Monitoring.” The consolidated workbook includes Sandaogou monthly and storm-event measurements; curated, analysis-ready records from six U.S. river datasets; a source registry with URLs, retrieval dates, and checksums; a variable dictionary; analytical quality-assurance information; and sampling-design definitions. The R scripts reproduce the cross-system hydrograph-phase comparisons, THg–MeHg surrogate tests, Bayesian event models, event-level sensitivity analyses, fixed-budget sampling evaluation, and main Figures 1–4. Reused public records remain attributable to the original USGS repositories and the Water Quality Portal listed in the Source Registry worksheet.