Exploring the spatiotemporal variation in vegetation phenology in the Yellow River basin has significant scientific significance for ecological governance, protection, and construction in the region. In this study, the GOSIF and GOSIF_GPP remote sensing products from 2001 to 2020 were selected, and the double logistic curve fitting and dynamic threshold method were used to obtain three vegetation phenology parameters: start of season (SOS), end of season (EOS), and length of season (LOS) in the growing season of the Yellow River basin over 20 years. The results showed the following: (1) The vegetation phenology in the Yellow River basin exhibited an obvious zonal distribution pattern from east to west and from south to north. The SOS was mainly concentrated in March-April, and 33.83% of the regions showed a significant advance. The EOS mainly ended in October-November, 7.46% of the region showed a significant delay. The LOS was approximately 150-200 days, with 28.20% showing significant prolongation. (2) SOS showed a gradual delay from east to west and from south to north, while EOS showed a gradual advance from east to west and from south to north. (3) The correlation between SOS and temperature and precipitation is not strong, and the influence of temperature and precipitation on SOS is not strong; EOS is highly correlated with temperature (69.76%), but not with precipitation (94.39%). Temperature is the dominant factor in EOS variation. In conclusion, temperature is the main factor affecting the interannual phenological changes in the Yellow River Basin.

Using technological advancements and analyzing urban water consumption patterns, this article employs GRACE satellite data and statistical records to conduct a comprehensive assessment and evaluation of water resource utilization efficiency across 34 prefecture-level cities in China’s three northeastern provinces—Liaoning, Jilin, and Heilongjiang—over the period spanning from 2003 to 2020. By utilizing the sophisticated Super-SBM model, the study delves into the spatial and temporal variations in terrestrial water reserves and green water usage efficiency. Additionally, the Tobit model is introduced to investigate the influencing factors of water resource utilization efficiency. The primary findings of the study are outlined below: The spatial distribution of terrestrial water resources in the three northeastern provinces reveals a clear north-south gradient, with abundant resources in the northern regions and scarcity in the southern parts. Seasonal fluctuations, albeit present, are relatively modest, with higher water storage levels typically observed in spring and summer, and lower levels in autumn and winter. Regarding the static water use efficiency among the 34 prefecture-level cities, Panjin stands out with the highest efficiency, whereas Qiqihar ranks lowest. Notably, 91.18% of the cities exhibit medium to high efficiency levels, reflecting commendable performance in water utilization throughout the region. Almost half of the cities have experienced an improvement in their water use efficiency compared to the previous year, signaling a gradual enhancement in water utilization capabilities. The average total factor productivity across the three northeastern provinces stands at 1.012, representing an annual growth rate of 1.2%. The efficiency of water resource utilization in these provinces is intricately linked to the technological progress index. To enhance water resource utilization efficiency, it is imperative to introduce advanced technologies, increase research investments, and foster technological advancements.

Rising vapor pressure deficit (VPD) suppresses crop photosynthesis, but whether antecedent deep-layer wetness systematically moderates this constraint remains unresolved in irrigated agricultural regions. We assembled a monthly 0.1° panel for 2019–2024 across the North China Plain by integrating gross primary production (GPP), satellite solar-induced chlorophyll fluorescence (SIF), ERA5-Land hydroclimate, cropland fractions, and irrigation information. The primary sample contained 163,002 observations from 3,881 grid cells. Pixel and year–month fixed-effects models separated VPD into temperature-linked and humidity-deficit components and tested their interactions with a standardized antecedent deep-layer wetness index. Robustness was evaluated across cropland thresholds, irrigation formulations, extreme-VPD metrics, sample years, and placebo specifications. The temperature-linked VPD component was negatively associated with SIF (β = -0.123, 95% CI: -0.198 to -0.049) and GPP (β = -0.158, 95% CI: -0.226 to -0.090), whereas the humidity-deficit component was negative but less precisely estimated. Interactions of antecedent deep-layer wetness with both VPD components were small and uncertain for SIF and GPP, with all principal confidence intervals spanning zero. Cumulative extreme-VPD exposure was also negatively associated with GPP, but its moderation by antecedent deep-layer wetness remained uncertain. These patterns persisted across cropland and irrigation specifications. Equivalence tests did not establish negligible interactions; the evidence therefore indicates no reproducible regional moderation rather than proof of no effect. Antecedent deep-layer wetness may retain local agronomic value, but it did not systematically offset atmospheric-dryness constraints at the regional scale. Distinguishing persistent atmospheric demand from context-specific apparent buffering is important for evaluating climate resilience in intensively managed croplands.

Gridded evapotranspiration (ET) and gross primary productivity (GPP) products describe agricultural water and carbon relationships. Interpreting their fitted boundaries requires evidence of empirical support and reproducibility. We assessed an ET-conditioned vapour pressure deficit (VPD) boundary in Hetao croplands using PML-V2.2a and ERA5-Land for 2019–2024. The frozen sample represented 193 native PML cells and 21,491 cell–date ET/GPP units. Three procedures separated baseline reproduction, strict extraction from the unchanged surface and refitting on identical records. A local boundary persisted after inverse-multiplicity weighting and single-record reconstruction, covering 32.3–35.4% of qualified ET columns. Boundary occurrence was repeatable, but post-turn slope intervals from both ERA5 and PML cell×year block schemes included zero. The primary deep-layer wetness subgroup displacement was undefined on common support, and turning eligibility depended on the side-count rule in a post-hoc sensitivity. Historical MOD16/MYD16 ET–VPM GPP comparisons did not recover a comparable continuous branch, although periods, products and support changed together. These findings distinguish a recurring local product association from stable turning geometry. The assessment provides an auditable sequence for checking native source units, support, connectivity and uncertainty before interpreting ET–VPD–GPP boundaries for agricultural water management. Independent crop and water-supply observations are needed to test management interpretations.

Using both GRACE satellite data and statistical records, we apply the advanced Super-SBM model in this study to evaluate the efficiency of water resource utilization in 34 prefecture-level cities across three provinces in Northeast China from 2003 to 2020. Furthermore, we employ the Tobit model to examine the factors influencing efficiency. Our findings suggest that while spatial clustering is moderately low, the efficiency of water resource utilization in the Northeast Region is praiseworthy and significantly correlates with the level of technological advancement. Four distinct categories can be identified among the prefecture-level cities based on the scale and technological efficiency of water resource utilization. To promote enhanced utilization of water resources, different regions should implement measures that are specifically tailored to their unique circumstances.