The historical distribution and future expansion of paddy rice fields in Asian highlands

Abstract

Urbanization and population growth are shrinking lowland rice areas, compelling exploration of Asia’s under‑studied highlands for future food security. Using earth observation data from 2000 to 2020 and machine learning method, we analyzed the distribution of paddy (irrigated) rice fields and their driving factors in Asian highlands (>1000 ma.s.l.). Highlands currently host 1.489 ± 0.176 millionha of rice, concentrated in the Tianshan–Tarim Basin, Hetao Plain along the Yellow River, and Yunnan–Guizhou Plateau. Altitude is the dominant constraint; additional precipitation is associated with reduced rice extent in the highlands, whereas population density and economic growth are associated with expansion. Our scenario modelling projects ~60% expansion and northward shift of high‑altitude paddies by 2035, yielding more nutrient‑rich, low‑contaminant grain and aiding saline–alkali reclamation. These findings highlight substantial, climate‑resilient capacity in Asian uplands to bolster sustainable rice supply and regional food security. This integrated assessment fills a critical knowledge gap regarding high‑elevation agroecosystems. (Figure presented.)