The Tabu catchment, a typical-desertified steppe in China, was selected as the study area to qualitatively analyze the interaction between surface water (SW) and groundwater (GW), and an integration of hydrochemical analysis and isotopic techniques was applied. The results show that the ion contents in SW and GW increased from upstream to downstream, and the hydrochemical evolutions were both controlled by rock weathering and influenced by evaporation. The δD–δ¹⁸O lines of SW and GW were δD = 5.14δ¹⁸O − 24.68 and δD = 6.89δ¹⁸O − 5.81, respectively. Along the I–I′ profile, the contents of most indices, δD and δ¹⁸O in SW and GW both showed increasing tendencies. All of the similarities in the hydrochemical characteristics and isotopic techniques indicated that SW was recharged by GW. The δD–δ¹⁸O inconsistency in SW and GW samples from midstream and downstream areas indicated that SW did not recharge to GW in these areas and was consumed by evaporation or replenished the moisture in the vadose zones. The runoff decreased, which was mainly caused by excessive exploitation of GW and a decline in the GW level. This study deepens the understanding of the hydrological cycle and provides guidance for the optimal combined utilization of SW and GW.

Groundwater is the main clean water resource in northern China, and its quality is critical for both human health and social sustainable development. Due to complex anthropogenic and/or geogenic processes, the sources of groundwater contaminants are not easy to determine. The Tabu River Basin, located in northern China, is an agriculture and pasture interlaced area in which phreatic groundwater is the predominant water resource for domestic and agricultural purposes. Groundwater with abnormally high levels of NO₃⁻, F⁻, and TDS was observed here based on 87 groundwater samples collected from the phreatic aquifer in 2022. In this study, hydrogeochemical and isotopic methods were used to trace groundwater contaminants in the phreatic aquifer, and a risk assessment was conducted to analyze their threat to human health. The results indicated that NO₃⁻ in the phreatic groundwater primarily originated from manure, the high concentration of TDS was highly associated with irrigation, and the enrichment of F⁻ was mainly controlled by geogenic factors, including alkaline condition, competitive adsorption, the dissolution of fluorine-bearing minerals, and cation exchange. A principal component analysis (PCA) showed that both anthropogenic (PC1, 50.7%) and geogenic (PC2, 19.9%) factors determined the quality of the phreatic groundwater in the study area. The human health risk assessment demonstrated that 98.9%, 92.0%, and 80.5% of the groundwater samples exceeded the permissible limit of the total noncarcinogenic risk for children, adult females, and adult males, respectively. The monitoring results from 2022 to 2023 suggested that phreatic groundwater contamination could not be mitigated through natural attenuation under the existing external pressures. Measures need to be taken to decrease the contamination of phreatic groundwater and enhance the groundwater sustainability in the Tabu River Basin. The findings of this study can provide a reference for sustainable groundwater development in the Tabu River Basin and other arid and semi-arid regions worldwide.

The Tabu River Basin (TRB) is one of the most ecologically fragile areas in the arid regions of northern China; it is a key component of the desert steppe north of the Yinshan Mountains. The fractional vegetation coverage (FVC) represents a vital indicator of ecological health in the TRB. In this study, we explored the impacts of climate change and human activities on vegetation growth and utilized Landsat data (30 m) from the Google Earth Engine to generate a long-term FVC dataset (1986–2023) in the TRB. Furthermore, we established a framework for quantitatively identifying the effects of climate change and anthropogenic activities on the FVC in desert steppe regions. The results revealed that: (1) the FVC exhibits considerable spatial heterogeneity, with higher values observed in the southeastern and southwestern areas and lower values in the northern part; (2) over the past 38 years, the annual average FVC has shown fluctuations, with a slight declining trend, while the Hurst exponent indicates a reverse persistence pattern in the FVC across the TRB; and (3) the correlation between the FVC and the temperature is marginally stronger than that with precipitation, and the influence of climate change on promoting the FVC outweighs the role of human activities. These results offer valuable insights for ecological restoration and sustainable development efforts and provide scientific support for monitoring vegetation in the region.

Duolun County, located in the Xilingol League, is a typical agro-pastoral ecotone in the north and is also the source of the Luan River system. Whether the development and utilization of regional water resources are reasonable and whether the water ecological environment is sustainable are the key issues that local government departments cannot ignore. By investigating the current situation of water resource development and utilization in Duolun County, this study revealed that the per capita water usage and the water usage per ten thousand yuan of GDP in Duolun County in 2020 were lower than the average level in the Inner Mongolia, and the level of water usage was relatively better. By using the nine-scale method and the analytic hierarchy process to construct an evaluation model of the water ecological environment of Duolun County, the comprehensive score of Duolun County was 8.35 (total score is 10), indicating that the water ecological environment in the study area was currently in a good state. The evaluation model has reference value for the future management of the water ecological environment in Duolun County and for continuous related research.

The huge pit formed after open-pit mining can partially change the local water system. Taking a typical open-pit coal mine in Wuhai City as an example, this study used survey data, hydrological analysis technology and a Rainfall-Run model to analyze the changes in the water system and runoff. The results indicate that the water system in the coal mining site has changed in the confluence path because of the mining pits and dumps formed by coal mining operations. Taking the local conditions into account, a water system restoration scheme using the pit for floodwater storage is proposed, that is, using the pit to retain upstream flood on the basis of an unobstructed downstream river flow. This scheme has several benefits. First, it can reduce the pressure of downstream flood control. Second, the sediment brought by the flood will be stored in the pit, which is conducive to reducing soil erosion. Third, it is conducive to the conservation of regional groundwater. Fourth, the retained water can be used for irrigation, which is conducive to the improvement of the surrounding ecology. The results of this study can provide references for the restoration and management of mining areas and ecological restoration in the arid desert area of Northwest China.