AI 中文总结
本研究提出基于网络的径流变化指数SAI，结合OLRRP v2与643个变化源，实现安大略省次流域尺度径流变化制图，经验证可作为大区域水文应用的客观筛选工具。
AI 中文摘要
水坝、水库和水力设施支撑着区域水资源管理，但可能通过连通的河网对下游远区的径流产生改变，使水文建模和水生生态系统评估变得复杂。现有指标通常仅在离散位置量化径流变化，限制了对潜在基础设施影响的空间连续制图。我们提出了径流变化指数（Streamflow Alteration Index, SAI），这是一种基于网络的筛选指标，可通过汇流网络将点源变化信号向下游传播。该框架包含成对的指数：SAI_I和SAI_II（取值范围0-100%），分别代表已确认（I级）和潜在（II级）变化源的影响。我们利用加拿大安大略省的安大略湖河网汇流产品第2版（Ontario Lake and River Routing Product Version 2, OLRRP v2）以及从省级数据集汇编的643个变化信号源清单，对SAI进行了应用。生成的SAI v1.0数据库在有水文监测和无水文监测的网络节点处，提供了无缝、高分辨率的次流域尺度制图与估算。我们通过将有水文监测的次流域分类为自然、条件性或变化类，并将这些分类与两个独立参考（参考水文流域网络（Reference Hydrometric Basin Network, RHBN）监测站和加拿大水文调查局（Water Survey of Canada, WSC）的自然与调节标签）进行比较，对SAI进行了验证。SAI将86%的RHBN自然监测站和86%的WSC自然监测站归类为自然类；在WSC调节监测站中，74%被归类为条件性或自然类。因此，SAI v1.0为大区域水文和水生应用提供了客观的筛选产品，无需详细的水坝运行信息，并为从国家到全球尺度的潜在径流变化制图提供了可扩展的基础。
英文摘要
Dams, reservoirs, and waterpower facilities support regional water management but can alter streamflow far downstream through connected river networks, complicating hydrologic modeling and aquatic ecosystem assessment. Existing indicators typically quantify alteration only at discrete locations, limiting spatially continuous mapping of potential infrastructure influence. We propose the Streamflow Alteration Index (SAI), a network-based screening metric that propagates point-based alteration signals downstream through a routing network. The framework includes paired indices, SAI_I and SAI_II (0-100%), representing influence from confirmed (Level I) and potential (Level II) alteration sources. We implemented SAI for Ontario, Canada, using the Ontario Lake and River Routing Product Version 2 (OLRRP v2) and an inventory of 643 alteration signal sources compiled from provincial datasets. The resulting SAI v1.0 database provides seamless, high-resolution, subbasin-scale mapping and estimates at gauged and ungauged network nodes. We validated SAI by classifying gauged subbasins as natural, conditional, or altered and comparing these classes with two independent references: Reference Hydrometric Basin Network gauges and Water Survey of Canada (WSC) Natural and Regulated labels. SAI classified 86% of RHBN natural gauges and 86% of WSC-natural gauges as natural. Among WSC-regulated gauges, 74% were classified as conditional or natural. SAI v1.0 therefore provides an objective screening product for large-domain hydrologic and aquatic applications without requiring detailed dam operating information and offers a scalable basis for national- to global-scale mapping of potential streamflow alteration.
CommentsThis manuscript is also available as a discussion preprint in Earth System Science Data Discussions, https://doi.org/10.5194/essd-2026-286
