京津冀地区是我国水资源承载压力最大、水生态系统受损最严重的区域之一，面向地区未来发展需求，系统研判水安全风险并提出针对性的应对策略，是实现京津冀协同发展和世界级城市群建设目标的科技保障。本文较为系统地梳理了有关京津冀地区的国家重大政策、经济社会发展态势、生态保护要求，分析了京津冀地区水安全现状、面临的形势以及有关重大科学问题。研究表明，①水资源供需矛盾是京津冀地区水安全保障的首要问题，未来区域水资源大概率将持续衰减1×10⁹ ~2×10⁹ m³，南水北调后续工程需调水量为3.9×10⁹~6×10⁹ m³以保障区域水系统安全；②针对区域河湖萎缩干涸、地下水超采严重的水生态现状，提出了河湖生态保护修复布局建议，明确了分区“健康地下水位”，即在恢复地下水埋深方面，山前平原区为8~20 m、中部平原区为3~5 m、城市区为6~10 m、东部沿海区为2~3 m；③针对防洪达标率低、蓄滞洪区启用难度大等地区防洪体系的薄弱环节，可加强常态与应急统筹管理，提前布局超标洪水等应对措施。相关研究立足京津冀地区新发展方位，着力形成前瞻且可操作的对策建议，以期为京津冀地区一系列重大国家战略任务的推进实施提供基础性参考。

The Beijing‒Tianjin‒Hebei region suffers from a high bearing pressure of water resources and its water ecosystem is severely damaged. For future development, it is necessary to analyze the water security risks and propose targeted countermeasures,thus to ensure the coordinated development of the Beijing‒Tianjin‒Hebei region and build this region into a world-class urban agglomeration. In this study, we summarize the key national policies, socio-economic development trends, and ecological protection requirements of the region. In addition, we analyze the water security status and relevant major scientific issues. Our findings are as follows. (1) The contradiction between supply and demand of water resources is the primary problem that threatens water security in the Beijing‒Tianjin‒Hebei region, and water resources in the region will probably continue to decay by 1‒2 billion m³. Therefore, to guarantee the security of the regional water system, 3.9‒6 billion m³ of water needs to be transferred into this region via the South-to-North Water Diversion Project. (2) To address the shrinkage and drying of regional rivers and lakes, groundwater overexploitation, and other severe water ecological problems, we propose a layout for the ecological protection and restoration of rivers and lakes and clarify the healthy groundwater levels for different areas: 8‒20 m in piedmont plains, 3‒5 m in central plains, 6‒10 m in urban areas, and 2‒3 m in the eastern coastal area. (3) To improve the weak links of the flood control system in the region such as a low pass rate of flood control standards and the difficulty in activating flood detention areas, this region needs to strengthen the routine‒emergency integrated management and prepare countermeasures for over-level floods.