Evolution of Urban–Agricultural–Ecological Spatial Structure Driven by Irrigation and Drainage Projects and Water–Heat–Vegetation Response

Urban Farm DB summary

Based on multitemporal remote-sensing data from 1985 to 2015, this study examined the evolution of urban-agricultural-ecological spatial structure and water-heat-vegetation responses driven by large-scale irrigation and drainage projects in the Inner Mongolia Hetao Plain, an arid/semi-arid region of China. It built a "multifunctionality-dynamic evolution" dual-principle classification system, combining maximum-likelihood classification of individual land types with conflict-pixel-resolution merging to achieve 90.82% classification accuracy, and used a land-use transfer matrix, a standard deviation ellipse model, land surface temperature (LST) inversion, and vegetation fractional coverage (VFC) analysis. The results showed: (1) spatial structure followed a path of short-term intense disturbance followed by long-term stable optimization, with agricultural space stability increasing 4.8%, ecological core area retention exceeding 90%, and urban space expansion shifting from external encroachment to internal filling; (2) VFC increased steadily in the central area (0.8% annual growth), fluctuated with recovery in the eastern area (±12% cyclic amplitude), and improved locally in the western area (key patches up 18%); (3) the LST-VFC relationship showed spatiotemporal misalignment, with 0.8-1.2°C anomalous cooling in the central region during construction despite a 15% VFC decrease, driven by irrigation water's thermal inertia, and a disrupted linear correlation after completion due to changes in crop phenology and plastic film mulching; and (4) the irrigation and drainage projects optimized water resource allocation, constructing a hub regulation model integrated with the Water-Energy-Food (WEF) Nexus.