Resource-based cities face numerous sustainability challenges, making the coupled and coordinated relationship between urbanization and the eco-environment critical for sustainable development strategies. The Loess Plateau is an essential energy base and ecologically fragile area in China, holding unique and significant research value. This research employed the Remote Sensing Ecological Index (RSEI) and the Compound Night Light Index (CNLI), based on MODIS and night light data, to investigate the socio-economic development and eco-environmental changes across 25 resource-based cities on the Loess Plateau (LP) in China over the past 20 years. The Coupling Coordination Degree Model (CCDM) and Multi-Scale Geographically Weighted Regression (MGWR) were utilized to assess the relationship between urbanization and ecological factors. The average RSEI values for these cities ranged from 0.4524 to 0.4892 over the 20 years, reflecting an upward trend with a growth rate of 8.13%. Simultaneously, the average CNLI values ranged from 1.5700 to 6.0864, with a change of 4.5164. Over the past two decades, all cities in the study area experienced rapid urbanization and ecological development. The correlation between urbanization and ecological factors strengthened, alongside an increasing spatial heterogeneity. While the coupling coordination relationship in most cities showed improvement, many remained within the low to middle grades. These findings enhance the understanding of the intricate relationships between urbanization and ecology, offering valuable insights for policy-making aimed at creating sustainable and livable resource-based cities.

The agro-pastoral ecotone of northern China (APENC), a typical semi-arid and ecologically vulnerable zone, has experienced considerable shifts in eco-environmental quality (EEQ) over the past two decades under the combined pressures of climate change and human activities. However, systematic understanding of the spatiotemporal evolution and driving mechanisms of EEQ in this region remains limited. Based on multi-source remote sensing data from 2000 to 2020, this study constructed an ecological quality assessment index (EQAI) using principal component analysis (PCA) and quantitatively identified driving factors through geographical detector modeling. The results reveal a consistent improvement in EEQ over the study period, characterized by a marked expansion of higher-quality areas and a contraction of degraded zones, though spatial heterogeneity remained evident. Global and local spatial autocorrelation analyses (Moran’s I) confirmed a distinct clustering pattern, with persistent low-value clusters in the northwest and high-value clusters in the southeast and north. Notably, the most pronounced EEQ enhancement occurred between 2000 and 2005. Overall, 90.24% of the region exhibited an improving trend, while only 9.76% showed degradation. Hurst exponent analysis further indicated that this improving trend is likely to continue in the future across most areas. Factor detection identified meteorological drivers (precipitation) as the strongest influencer on EEQ, followed by land use type. Socioeconomic factors demonstrated relatively minor impact. These findings provide a scientific basis for ecological restoration policy-making and sustainable land management in the APENC and other ecologically fragile transitional regions.

Xerophytic vegetation re-regulates and allocates water resources through canopy interception, root water uptake and transpiration, and changes the water budget among precipitation, runoff, interception and infiltration, thus having a significant impact on the processes of the hydrological cycle. In this study, we investigated the effect of xerophytic shrub-Salix on soil water redistribution and water budget through an in situ monitoring experiment combined with two-dimensional vegetation water consumption modeling. The results showed that, due to the interception effect of root water uptake, it was difficult for precipitation infiltration to recharge deep soil water and groundwater. The measured data of soil moisture content, hydraulic head and precipitation were used to verify and calibrate the performance of the soil water flow model in the vadose zone by HYDRUS-2D. The effect of roots system on soil water was simulated, and the appropriate spacing of Salix replanting was estimated. Combined with the relationship between the transverse roots system and the crown width obtained by the investigation, it was determined that the spacing between the Salix should be greater than five times the crown width, so that the balance between the water consumption of Salix and the water supply of deep soil by precipitation could be considered. The results of this study are important for estimating groundwater recharge in arid areas and provide practical vegetation replanting options for similar regions.

The water consumption processes of vegetation play an important role in water resource management in semiarid regions, while the difference in water consumption between native and exotic species is unclear. In this study, the exotic Pinus sylvestris L. var. mongholica Litv. (Pinus) and the native Salix psammophila (Salix) in Mu Us Sandy Land were selected as the research objects, and their water consumption characteristics were studied via in situ experiment and stable isotopes (δ²H and δ¹⁸O). Results revealed that vegetation water consumption caused spatial variation in soil moisture, allowing the soil profile to be divided into active, stable, capillary support and saturated zones. Pinus primarily used water from the active and stable zones, whereas Salix relied more on the capillary support and saturated zones. Water consumption patterns also varied seasonally, for example, at the beginning of growth (May–June), Salix and Pinus mainly use shallow soil water and begin to use deep soil water and groundwater with growth. During July–September, they absorb soil water mainly in the active zone and stable zone. Both Salix and Pinus can freely switch water sources between deep and shallow layers according to water demand. The seasonal fluctuations in precipitation and groundwater level were the main factors driving the seasonal changes in the water consumption of the two vegetation types. Pinus has better strategies to adapt to droughts than Salix, but its water consumption is higher than that of Salix. Therefore, proper management is needed to control the reasonable density of Pinus plantation to balance the water consumption of vegetation and groundwater recharge. The results can provide a scientific basis for the reasonable vegetation reconstruction in the Mu Us Sandy Land.