Early warning and formation mechanism analysis of groundwater environment in irrigation area, Guanzhong Basin

Long-term intensive human activities in irrigation areas seriously threaten their groundwater environment. In this study, the early warning status of the groundwater environment and the possible influencing factors were analyzed based on 63 samples using the BP neural network and gray relational analysis. For groundwater depth, the upper limits of blue and red warnings were set at 5 m and 2 m, respectively. The prediction results show that the maximum value of the water table in the study area exhibits a downward trend, whereas the minimum value exhibits an upward trend. Only blue and yellow warnings occur in 2025, implying that the early warning state of the groundwater level, will improve in the later stage. The early warning grades of groundwater salinity in 2025 were also analyzed and the results show that orange warning is dominant, accounting for 53.97%, with a distribution area of about 552.811 km², followed by yellow warning and blue warning, without any red warning. The early warning grade of salt content in the highest in the hinterland of the study area. This is because the middle area has a shallow groundwater level with strong evaporation. By analyzing the factors affecting groundwater level and salinity, evaporation was found to be the strongest factor influencing groundwater level and salinity, followed by precipitation and irrigation infiltration. Furthermore, on the basis of the aforementioned results, six targeted countermeasures are put forward. The findings will contribute toward the protection of the local livelihood and achieving sustainable development of water resources.