Spatial and Temporal Dynamics of Water Use Efficiency and Climate Influence in The Central Highlands of Vietnam via Satellite Time Series

Abstract

This study investigates the spatial and temporal patterns of water use efficiency (WUE) anomalies across the Central Highlands of Vietnam from 2001–2024 via MODIS time series data, with a focus on seasonal differences and climatic drivers. The results revealed pronounced interannual and spatial variability in the WUE, with significant improvements observed during 2004, 2015, and 2021–2024 and substantial declines during 2005–2008, 2010–2013, and 2016–2017, which coincided with major drought events in the region. Seasonal analysis indicated that WUE was lower during the early dry season and peaked during the postmonsoon months (October–November), reflecting the interplay between water availability and vegetation productivity. Land cover-specific trends revealed greater variability in rainfed croplands than in forests. Additionally, spatial trend analysis revealed widespread positive WUE trends during the dry and rainy seasons, accounting for nearly 35% of the study area. Correlation analysis demonstrated that WUE was more sensitive to climate variables during the dry season, particularly showing positive associations with solar radiation and negative associations with soil moisture and rainfall. During the rainy season, the WUE responses were weaker and more stable. These findings highlight the vulnerability of WUE to climatic variability during the dry season and emphasize the importance of adaptive land and water management strategies to increase ecosystem resilience under future climate change scenarios.