A Multi-Product Robustness Audit of Long-Term Soil-Moisture Trends on the Chinese Loess Plateau
Year: 2026
Type: article
Abstract: Long-term soil-moisture trends on the Chinese Loess Plateau are inferred from gridded products, but product choice can alter whether change is read as drying or wetting. We audited trends from the Global Land Data Assimilation System (GLDAS), ECMWF Reanalysis v5 Land (ERA5-Land), Soil Moisture of China by in situ data (SMCI), and Global Land Evaporation Amsterdam Model root-zone soil moisture (GLEAM SMrz) for 2001–2022, with an endpoint-extension test to 2025. We compared product-specific trends, spatial agreement, core-product medians, product-set bridge and leave-one-out sensitivities, and associations with precipitation, vapor pressure deficit, forest–shrub–grass cover change, and a potential-storage proxy. The core products shared substantial detrended interannual variability, yet their regional trend point estimates did not converge in sign. GLDAS gave a positive regional Sen-slope estimate, whereas ERA5-Land, SMCI, and GLEAM SMrz gave negative estimates. The core-product median was negative over 72.7% of the study area, but unanimous decline occurred over only 24.9%, and 63.5% showed mixed product signs. Only 36.9% of the area retained direction across all five robustness checks, and no environmental variable achieved repeatable same-direction support across all core products. Hydrologically, these results indicate that apparent Loess Plateau wetting or drying should be interpreted as product-dependent evidence of soil-water availability rather than as a universally robust soil-moisture trend or direct environmental response.
Source: Water
DOI: 10.3390/w18172104
Authors: Rongqi Li, Huerxidaimu Adili, Yuanhe Bai, Ruixuan Lan, Fei Wang
Language: English
Subfield: Environmental Engineering
Field: Environmental Science
Domain: Physical Sciences
SDGs: Climate action, Life on land
Open Access status: gold
Estimated APC paid: $3,137
OpenAlex ID: W7204230087