Ariano Sarah, Ali Geneviève
Department of Earth Sciences, University of Toronto, 27 King's College Circle, Toronto, ON, M5S 1A1, Canada.
Department of Earth and Planetary Sciences, McGill University, 3450 University Street, Montreal, QC, H3A 0E8, Canada.
Sci Rep. 2025 May 14;15(1):16743. doi: 10.1038/s41598-025-00244-7.
Zonal classifications, such as those based on biomes and ecozones, are commonly used to contextualize short-term dynamics and long-term environmental change. One challenge in hydrology is the lack of zonal classifications that explicitly incorporate flow statistics. To date, few studies have evaluated whether non-hydrological zonal classifications can serve as proxies for flow dynamics across large, heterogenous regions. Taking Canada as an example, the focus was on 2531 hydrometric stations for which select streamflow signatures were computed. Those signatures, coupled with catchment characteristics, were used to distinguish flow regimes based on their degree of temporal variability-categorizing them as erratic or persistent-and their main water sources-either shallow subsurface flow or groundwater. Results show that catchments with higher cropland and urban cover and higher percentages of clay soils were associated with erratic regimes fed by shallow subsurface flow. Conversely, catchments with higher forest and semi-permanent water features were associated with persistent regimes. The high degree of intra-region and inter-region hydrologic heterogeneity was typically not well captured by non-hydrological zonal classifications. Caution is therefore warranted when using existing non-hydrological zonal classifications for regional water policy planning, as they may lead to a mischaracterization of spatial differences in streamflow patterns.
区域分类，例如基于生物群落和生态区的分类，通常用于将短期动态和长期环境变化置于背景之中。水文学面临的一个挑战是缺乏明确纳入流量统计数据的区域分类。迄今为止，很少有研究评估非水文区域分类是否可以作为大型异质区域流量动态的替代指标。以加拿大为例，重点关注了2531个水文测量站，计算了这些站点的选定径流特征。这些特征与流域特征相结合，用于根据时间变化程度区分径流状态——将它们分类为不稳定或持续——以及它们的主要水源——浅层地下径流或地下水。结果表明，农田和城市覆盖率较高以及粘土比例较高的流域与由浅层地下径流供给的不稳定径流状态相关。相反，森林和半永久性水体特征较高的流域与持续径流状态相关。非水文区域分类通常不能很好地捕捉区域内和区域间高度的水文异质性。因此，在将现有的非水文区域分类用于区域水资源政策规划时要谨慎，因为它们可能会导致对径流模式空间差异的错误描述。
