Groundwater sustainability initiatives, including sustainable yield and watershed policy protection policies, are growing globally in response to increasing demand for groundwater, coupled with concerns about the effects of climate and land-cover change on groundwater supply. Improved understanding of the impacts of watershed management on groundwater yields and management costs—particularly in the broader context of climate and land-cover change—is critical to inform these initiatives and facilitate integrated land and water management. This study develops a novel, spatially explicit groundwater hydrologic ecosystem services framework, which combines stakeholder-defined land-cover scenarios, sustainable yield estimation using a groundwater simulation optimization approach, and economic valuation, and applies it in the most heavily utilized aquifer Hawai‘i (USA). Sustainable yield estimates and resulting differences in replacement costs are estimated for six land-cover scenarios (with varying levels of urban development and watershed management) crossed with two water demand scenarios in a context of a dry future climate (Representative Concentration Pathway [RCP] 8.5 mid-century). Land-cover change is found to be an important, though less significant drive of changes in groundwater recharge than climate change. The degree of watershed protection, through preventing the spread of high-water-use, invasive plant species, is projected to be a much stronger land-cover signal than urban development. Specifically, full forest protection increases sustainable yield by 7–11% (30–45 million liters per day) and substantially decreases treatment costs compared with no forest protection. Collectively, this study demonstrates the hydrologic and economic value of watershed protection in a context of a dry future climate, providing insights for integrated land and water policy and management in Hawai‘i and other regions, particularly where species invasions threaten source watersheds.

地下水可持续性倡议，包括可持续产量和流域政策保护政策，正在全球范围内发展，以应对不断增长的地下水需求，以及对气候和土地覆盖变化对地下水供应的影响的担忧。更好地了解流域管理对地下水产量和管理成本的影响——尤其是在更广泛的气候和土地覆盖变化背景下——对于为这些举措提供信息并促进综合土地和水资源管理至关重要。本研究开发了一种新颖的、空间明确的地下水水文生态系统服务框架，该框架结合了利益相关者定义的土地覆盖场景、使用地下水模拟优化方法的可持续产量估计以及经济估值，并将其应用于使用率最高的含水层夏威夷（美国）。在未来干旱气候（代表性浓度路径 [RCP] 8.5）与两种需水情景交叉的六种土地覆盖情景（具有不同的城市发展和流域管理水平）中，对可持续产量估算和由此产生的重置成本差异进行了估算世纪中叶）。发现土地覆盖变化是地下水补给变化的一个重要驱动因素，但其影响不如气候变化。通过防止高用水量入侵植物物种的传播，流域保护程度预计将成为比城市发展更强的土地覆盖信号。具体来说，与没有森林保护相比，全面的森林保护可将可持续产量提高 7-11%（每天 30-4500 万升）并大幅降低处理成本。总的来说，这项研究证明了在未来干旱气候背景下流域保护的水文和经济价值，为夏威夷和其他地区的综合土地和水资源政策和管理提供了见解，特别是在物种入侵威胁源流域的地方。