Multi-Criteria evaluation and ranking of 28 precipitation products over China

Multi-source precipitation products exhibit strong regional differences across China’s complex monsoon climates and pronounced topographic gradients, making single-metric evaluations insufficient for product selection. This study evaluates 28 widely used precipitation products over China from four categories: gauge-based, satellite-derived, reanalysis, and multi-source merged products. Product performance is assessed at both grid and seven major climate-zone scales using conventional error statistics, consistency metrics, ETCCDI (Expert Team on Climate Change Detection and Indices) extreme precipitation indices, precipitation detection skill, and SAL (Structure–Amplitude–Location) diagnostics for the intensity, structure, and location of heavy-rainfall events. These indicators are further synthesized within an ensemble multi-criteria decision-making framework to derive national and regional rankings. The results show that most products capture daily precipitation variability reasonably well, but intense rainfall events remain associated with widespread amplitude underestimation and enlarged errors, while extremes also exhibit notable structural distortion and location bias. At the national scale, multi-source merged generally show greater overall robustness. Regional rankings further reveal strong spatial heterogeneity: arid zones and some humid regions tend to favor reanalysis-type products, whereas plateau regions show higher sensitivity to satellite products and greater ranking uncertainty. Overall, this study provides a transparent and application-oriented framework for integrated precipitation product evaluation and ranking over China. The resulting national and climate-zone-specific rankings offer practical guidance for precipitation product selection, candidate-pool construction for multi-source merging, and hydrometeorological risk analyses.