| Name | Explanation | |
|---|---|---|
| B1 | Steady agricultural irrigation development | Characterized by moderate water stress and balanced contributions from climate efficiency and yield factors. |
| B2 | Agricultural expansion- intensification group | Dominated by large-scale cultivated area expansion and yield-driven irrigation demand. |
| B3 | Agricultural contraction- intensification group | Features significant reduction in cultivated area but heightened yield-induced water pressure. |
| B4 | Specialty agriculture development group | Exhibits low water stress with efficiency gains offset by structural adjustments. |
| B5 | Agricultural water-stressed development group | Combines severe water stress with conflicting drivers of efficiency gains and scale-driven demand. |
Figure 6 Spatiotemporal variation characteristics of irrigation water demand driving zones in the Yellow River Basin: (a) Irrigation water demand driving characteristics of each zone; (b) spatial distribution of each zone during the periods 2000-2010 and 2010-2019; (c) change trajectories of city zones within the two periods
Figure 7 Annual average sown area (a), annual average irrigation water demand for wheat and maize (b), annual average sown area after optimization (c), annual average irrigation water demand for wheat and maize after optimization (d) in key agricultural water-saving zone (prefecture-level cities of the upper Yellow River Basin transition from B2 to B5 and persistent B5 classification)