| 09 Mar 2026
A 500-m crop water requirement and irrigation water demand dataset for 25 crop types in the Yellow River Basin (2000–2020): Revealing significant underestimation from incomplete crop coverage
Abstract. Accurate estimation of irrigation water demand (IWD) is fundamental for sustainable water resources management in water-scarce agricultural regions. However, existing IWD assessments typically consider only a limited number of major crops, potentially leading to systematic underestimation of basin-scale water demand. This study develops a comprehensive high-resolution (500 m) dataset of crop water requirement (CWR, equivalent to the net irrigation water requirement, i.e., crop evapotranspiration minus effective precipitation) and IWD (CWR divided by irrigation water use efficiency) for the Yellow River Basin (YRB) covering 25 crop types from 2000 to 2020. We first evaluated eight remote sensing-based cropland datasets against statistical records from 135 administrative units, identifying the Global Land Analysis and Discovery (GLAD) dataset as optimal. CWR and IWD were estimated using the FAO Penman-Monteith approach with spatially explicit crop coefficients and spatiotemporally dynamic irrigation water use efficiency coefficients. The dataset provides two complementary versions: a sown area-based version reflecting the full theoretical agricultural water gap (multi-year average CWR and IWD of 548.3 × 108 m3 and 1086.8 × 108 m3, respectively), and an irrigated area-based version constrained by actual irrigation extent (258.6 × 108 m3 and 508.4 × 108 m3), broadly consistent with independent estimates of actual irrigation water consumption. Our results reveal that considering only five major crops would underestimate CWR and IWD by approximately 33 % and 34 %, respectively, with the largest underestimation in the upper reach (approximately 45 %). More importantly, incomplete crop coverage not only causes quantitative bias but also misrepresents temporal dynamics, yielding opposite trend directions in some sub-basins. Sensitivity analysis indicates that 12–15 crop types are required to capture over 90–95 % of basin-scale water demand, with vegetables and tubers ranking among the top six contributors despite being frequently omitted in previous studies. The dataset (Tang and Zhang, 2026) is publicly available at https://doi.org/10.5281/zenodo.18628324.
