Spatiotemporal evolution and driving mechanisms of agricultural drought across different spatial scales in Northeast China

Northeast China (NEC), one of the world’s four major black soil regions and a key grain-producing area in China, spans a pronounced hydro-climatic gradient from humid to semi-arid conditions under a temperate continental monsoon climate. This study constructed the temperature vegetation dryness index (TVDI) for NEC during 2000–2022 to characterize agricultural drought at multiple spatial scales. The spatiotemporal patterns of drought were examined for NEC as a whole and across 12 divisions defined by geographic subregions, climate zones, and ecosystem types. In addition, the optimal parameter geographical detector (OPGD) was applied to quantify the factors controlling drought distribution and its spatiotemporal evolution. From 2000–2022, TVDI decreased at a rate of −2.20 × 10 −3 yr −1 , indicating an overall alleviation of agricultural drought in NEC. However, drought severity showed marked spatial heterogeneity, with the Liao River Plain experiencing the most severe drought. Drought intensified from humid to semi-humid to semi-arid zones, while the wetting trend weakened accordingly. Forest ecosystems showed stronger drought resistance than grasslands and croplands. PET, land use/land cover, and temperature primarily controlled the spatial distribution of drought, whereas temperature, PET, and precipitation dominated its spatiotemporal evolution. These findings provide new hydrological evidence that agricultural drought in NEC is jointly regulated by atmospheric water demand, water supply conditions, and land surface characteristics. • Agricultural drought weakened overall but remained highly heterogeneous in NEC. • Drought patterns varied across geographic, climatic, and ecosystem divisions. • PET, LUCC, and temperature controlled drought spatial patterns. • Temperature, PET, and precipitation drove drought spatiotemporal evolution.