植被覆盖与水平衡要素的演变及交互关系对提升水资源和林草保护的匹配性、促进高质量发展具有重大意义。本文以1982—2019年的归一化植被指数、降水量、实际蒸散发量和产水量为关键指标，以1 km×1 km栅格为基本分析单元，在气候分区、植被分区、三级流域、一级流域等不同分区范围，解析了植被覆盖与水平衡要素的时空演变规律和空间交互关系，识别出“植被增加 ‒ 产水降低”矛盾突出的区域，并揭示了植被 ‒ 产水的空间交互关系的复杂性，在此基础上明晰了“水绿统筹”原则下林草科学保护和恢复面临的主要挑战。研究表明，全国平均降水、实际蒸散发、产水量的多年平均值整体变化不显著，但在气候分区、植被分区、流域分级分析时显著性凸显；不同气候分区、植被分区和分级流域中“植被增加 ‒ 产水降低”矛盾空间差异显著，如暖温带半湿润地区、暖温带落叶阔叶林区域、温带荒漠区域、温带草原区域等区域，淮河、海河、辽河、黄河流域等一级流域以及35.7%的三级流域矛盾尤为突出。研究发现，“三北”防护林工程、退耕还林还草工程的主要实施区域（如西北诸河、黄河流域等）和识别出的“植被增加 ‒ 产水降低”矛盾突出区域具有高度重合性，需警惕重大工程实施区的植被生态需水保障风险。研究建议，提升林草保护与恢复决策的科学性，目标分解需考虑天然径流下降风险，加大重大工程生态需水保障，以推动未来林草科学保护和水资源管理。

The interactions between vegetation and water balance elements play a crucial role in enhancing the compatibility of water resources and forest-grassland conservation, thereby promoting high-quality development. This study employs key indicators, including the Normalized Difference Vegetation Index (NDVI), precipitation, actual evapotranspiration, and water yield, spanning the years 1982 to 2019, with a 1 km × 1 km grid as the fundamental analytical unit. It examines the spatiotemporal evolution patterns and interrelationships between vegetation and water balance elements across various spatial scales, such as climatic zones, vegetation zones, tertiary watersheds, and primary watersheds. It identifies regions and watersheds with pronounced conflicts between vegetation increase and water yield reduction, and reveals the spatial interactions between vegetation and water yield. Based on these findings, the study outlines the key challenges and recommendations for scientifically restoring and conserving forests and grasslands under the principle of "coordinated water and vegetation management". While national averages for precipitation, actual evapotranspiration, and water yield exhibit no significant trends, notable spatial patterns emerge at specific scales. Significant conflicts between vegetation increase and water yield reduction are observed in regions such as the warm temperate semi-humid zone, warm temperate deciduous broadleaf forest zone, temperate desert zone, and temperate grassland zone, as well as in major watersheds such as the Huaihe, Haihe, Liaohe, and Yellow Rivers, and in 35.7% of tertiary watersheds. Additionally, the main implementation areas of major ecological projects like the Three-North Shelterbelt Program and the Grain for Green Program (e.g., Northwest Rivers and the Yellow River basin) overlap significantly with the identified conflict-prone areas, raising concerns about the ecological water needs of vegetation in these areas. The study recommends enhancing decision-making scientificity, accounting for natural runoff reduction risks in target setting, and strengthening ecological water supply assurance for major projects, thereby providing valuable insights for the future scientific conservation of forests and grasslands.