Jilin Province, an important commodity grain base in China, relies on groundwater resources for its agricultural development. The implementation of a series of policies, including agricultural subsidies and food security policies, has led to a rapid expansion of the sowing area in recent decades, resulting in an increase in agricultural water demand. This has had a significant impact on the groundwater system. It is therefore imperative to understand the dynamics of the groundwater to ensure the security of water resources, ecological security, and food security. An evaluation of the sustainability of groundwater resources in Jilin Province was conducted through a quantitative analysis of the reliability, resilience, and vulnerability of groundwater. This analysis was informed by the inversion of changes in groundwater reserves over a period of 249 months, commencing from 2002-04 to 2022-12. The inversion process utilized data from the Gravity Recovery and Climate Experiment (GRACE) gravity satellite and Global Land Data Assimilation System (GLDAS), offering a comprehensive view of the temporal dynamics of groundwater reserves in the region. The results indicated the following: (1) Groundwater storage (total amount of water below the surface) in Jilin Province exhibited an overall decreasing trend, with the highest groundwater level recorded in June and the lowest in September on a monthly basis. (2) Prior to September 2010, groundwater reserves were in surplus most of the time. From October 2010 to August 2018, however, they began to fluctuate between surplus and deficit states. Since September 2018, the reserves have been in a long-term deficit, showing an overall downward trend. (3) Prior to 2005, the groundwater system was at a high/extremely high level of sustainability. However, following 2011, it fell to a very low level of sustainability and has continued to deteriorate. (4) The maximum information coefficient and correlation analysis indicate that the sown area is the most significant factor contributing to the decline in the sustainability of the groundwater system. This study reveals the spatial and temporal distribution pattern and evolution trend of groundwater resources sustainability in Jilin Province, and provides theoretical and data support for regional groundwater resources protection and management.

Existing assessments of geothermal water extraction suitability in sedimentary basins are often limited by subjective indicator selection, insufficient consideration of inter-indicator relationships, and weak adaptability to low- to medium-temperature geothermal systems. Taking Lindian County, a representative geothermal field in the northern Songnen Plain, as a case study, this work develops a process-based assessment framework integrating spatial zoning, key-factor identification, indicator quantification, and weighted evaluation. The study area was divided into 16 sub-regions using dominant-factor zoning and GIS-based overlay analysis. Five core driving indicators were then identified from 20 candidate indicators using DEMATEL, and their weights were determined using AHP after passing the consistency test. A four-level scoring scheme was established, and the linear weighted-sum method was used to generate quantitative suitability scores and spatial zoning maps. The results indicate that Lindian County has generally favorable conditions for geothermal water extraction, although clear spatial heterogeneity exists among the sub-regions. Overall, 87.5% of the sub-regions were classified as having good or relatively good suitability. WAI and WDI were identified as the optimal zones, whereas KAII and BEII showed relatively poor suitability. The spatial pattern supports the interpretation that geological structure controls both reservoir development and geothermal fluid occurrence, with hydrochemical properties and reservoir water-richness acting as secondary controlling factors. The proposed framework improves the transparency of indicator selection and provides a practical basis for zoning-based geothermal water extraction planning in similar sedimentary basins.

The Integrated Valuation of Ecosystem Services and Trade-Offs (InVEST) model with the distributed hydrological model Soil and Water Assessment Tool (SWAT) were implemented. The SWAT model quantifies and visualizes water production and groundwater reserves in the Mudanjiang River Basin, employing the groundwater runoff modulus method to calculate groundwater recharge in the basin. This study aims to assess the model’s applicability in cold basins and subsequently analyze groundwater distribution characteristics, water reserves, and the exploitable volume. It serves as a reference for the judicious allocation of groundwater resources and the preservation of the local aquatic ecosystem. The study indicates the following: (1) Utilizing the monthly runoff data from the Mudan River hydrologic station, SWAT simulation and calibration were conducted, yielding a determination coefficient (R²) of 0.75 and a Nash–Sutcliffe efficiency coefficient (NS) of 0.77, thereby satisfying fundamental scientific research criteria. The water yield predicted by the InVEST model aligns closely with the water resources bulletin of the research region. (2) The data from the water production module of the InVEST model indicate that the average annual water production during the research period was 6.725 billion m³, with an average annual water production depth of 148 mm. In 2018, characterized by ample water supply, the water output was at its peak, with a depth of 242 mm. In 2014, the water depth recorded was merely 16 mm. (3) Throughout the study period, the average annual flow of the Mudan River was 4.2 billion m³, whereas the groundwater reserve was 24.13 (10⁸ m³·a⁻¹). In 2013, the maximum groundwater reserve was 38.42 (10⁸ m³·a⁻¹), while the minimum reserve in 2014 was 2.36 (10⁸ m³·a⁻¹), suggesting that the region was predominantly experiencing sustainable exploitation. (4) The mean groundwater runoff modulus is 0.28 L/(s·km²), with a peak annual recharge of 15.4 (10⁸ m³·a⁻¹) in 2013 and a lowest recharge of just 3.2 (10⁸ m³·a⁻¹) in 2011.

The current study reveals a deficiency in knowledge regarding the assessment of the breadth of prohibitions and restrictions on water withdrawal for the development and utilization of geothermal resource projects involving water withdrawal. To resolve this matter, this report outlines the extent of water withdrawal prohibitions and restrictions for geothermal energy development and use projects, with a particular focus on Lindian County’s medium- and low-temperature geothermal resources of the sedimentary basin type. A comprehensive consideration of geological, hydrological, and other factors was made in light of the need for global energy transformation and the benefits and drawbacks of geothermal energy. The study first divided Lindian County into 17 zones using the zoning method of dominant sign and superposition method, which was then combined with the hierarchical analysis method. The evaluation indexes were then quantitatively graded and evaluated in the 17 zones using the linear weighted sum method, and each zone’s suitability for water abstraction was ultimately determined. The limited and banned water withdrawal range of the Lindian County geothermal energy development and utilization project is defined based on the water withdrawal characteristics of the 17 subareas. The rational development of geothermal energy, the preservation of the natural environment, and the advancement of the geothermal industry in Lindian County are all greatly impacted by this study, which offers a more sophisticated methodology for the assessment of water withdrawal type projects of sedimentary basin-type medium- and low-temperature geothermal resources.