Evaluating Noah-MP simulated runoff and snowpack in heavily burned Pacific-Northwest snow-dominated catchments

These data support results presented in the manuscript by Abolafia-Rosenzweig et al., "Evaluating Noah-MP simulated runoff and snowpack in heavily burned Pacific-Northwest snow-dominated catchments" Abstract Terrestrial hydrology is altered by fires, particularly in snow-dominated catchments. However, fire impacts on catchment hydrology are often neglected from land surface model (LSM) simulations. Western U.S. wildfire activity has been increasing in recent decades, and is projected to continue increasing over at least the next three decades, and thus it is important to evaluate if neglecting fire impacts in operational LSMs is a significant error source that has a noticeable signal among other sources of uncertainty. We evaluate a widely-used state-of-the-art LSM (Noah-MP) in runoff and snowpack simulations at two representative fire-affected snow-dominated catchments in the Pacific Northwest: Andrew’s Creek in Washington and Johnson Creek in Idaho. These two catchments are selected across all western U.S. fire-affected catchments because they are snow-dominated and experienced more than 50% burning in a single fire event with minimal burning outside of this event, which allows analyses of distinct pre- and post-fire periods. There are statistically significant shifts in model skills from pre- to post-fire years in simulating runoff and snowpack. At both study catchments, simulations miss enhancements in early-spring runoff and annual runoff efficiency during post-fire years, resulting in persistent underestimates of annual runoff anomalies throughout the 12-year post-fire analysis periods. Enhanced post-fire snow accumulation and melt contributes to observed but unmodeled increases of spring runoff and annual runoff efficiency at these catchments. Informing simulations with satellite observed land cover classifications, leaf area index, and vegetation fraction do not consistently improve the model ability to simulate hydrologic responses to fire disturbances.

本数据集支撑Abolafia-Rosenzweig等人发表于论文《在受严重焚烧的太平洋西北地区积雪主导流域中评估Noah-MP模拟径流与积雪覆盖》（Evaluating Noah-MP simulated runoff and snowpack in heavily burned Pacific-Northwest snow-dominated catchments）的研究结果。摘要：野火会改变陆地水文过程，在积雪主导流域中这一效应尤为显著。然而，陆面模型（Land Surface Model, LSM）的模拟往往未考虑野火对流域水文的影响。近数十年来，美国西部野火活动愈发频繁，且预计未来至少30年内仍将持续加剧。因此，评估业务化陆面模型中忽略野火影响是否会成为显著的误差来源，且该误差在诸多不确定性因素中具备可识别的信号，具备重要研究价值。本研究针对太平洋西北地区两处受野火影响的典型积雪主导流域——华盛顿州的安德鲁溪（Andrew’s Creek）与爱达荷州的约翰逊溪（Johnson Creek），评估了当前广泛应用的先进陆面模型Noah-MP的径流与积雪覆盖模拟效果。从全美西部受野火影响的流域中遴选这两处研究对象，是由于其均为积雪主导流域，且在单次野火事件中过火面积占比超过50%，事件外几乎无额外过火，这为区分野火前后两个时段的对比分析提供了理想条件。在模拟径流与积雪覆盖的过程中，模型性能在野火前后年份间出现了具有统计学意义的显著变化。在两处研究流域中，野火后年份的早春径流与年径流效率均出现提升，但模型未能复现这一变化，导致在长达12年的野火后分析时段中，模型持续低估了年径流异常值。野火后积雪蓄积与融雪过程的增强，是观测到的春季径流与年径流效率提升的成因，但这一过程并未被当前模型所刻画。通过卫星观测的土地覆盖分类、叶面积指数与植被占比对模拟进行约束，未能持续提升模型模拟野火扰动下水文响应的能力。