该研究组展示了从20世纪60年代到21世纪初，这些冰冻圈供养的河流的季节性沉积物输运变化，其特征分别为冰川、河流、河流和混合模式。春季由于融雪减少和侵蚀性降雨增多，沉积物运输转向以雨水为主。夏季的特点是冰川融水脉冲加剧，雨洪事件特别增加了沉积物通量。
他们的研究强调，极端水文气候和冰冻圈退化的增加，导致河流通量变异性的放大和夏季沉积物峰值的升高，这可能威胁下游河流基础设施安全和生态系统，并加剧冰川/洪积洪水。研究人员进一步提供了一个月尺度的沉积物可利用性运输模型，该模型可以再现这种状态变化，并有助于在未来气候和水文变化的情况下，在更广泛的冰冻圈区域促进可持续的水库运行和河流管理。
研究人员表示，气候变化影响冰冻圈供养的河流，改变季节性泥沙动态，影响周期性河流物质供应和下游社区全年的水-食物-能源供应。
附：英文原文
Title: Shifted sediment-transport regimes by climate change and amplified hydrological variability in cryosphere-fed rivers
Author: Ting Zhang, Dongfeng Li, Amy E. East, Albert J. Kettner, Jim Best, Jinren Ni, Xixi Lu
Issue&Volume: 2023-11-10
Abstract: Climate change affects cryosphere-fed rivers and alters seasonal sediment dynamics, affecting cyclical fluvial material supply and year-round water-food-energy provisions to downstream communities. Here, we demonstrate seasonal sediment-transport regime shifts from the 1960s to 2000s in four cryosphere-fed rivers characterized by glacial, nival, pluvial, and mixed regimes, respectively. Spring sees a shift toward pluvial-dominated sediment transport due to less snowmelt and more erosive rainfall. Summer is characterized by intensified glacier meltwater pulses and pluvial events that exceptionally increase sediment fluxes. Our study highlights that the increases in hydroclimatic extremes and cryosphere degradation lead to amplified variability in fluvial fluxes and higher summer sediment peaks, which can threaten downstream river infrastructure safety and ecosystems and worsen glacial/pluvial floods. We further offer a monthly-scale sediment-availability-transport model that can reproduce such regime shifts and thus help facilitate sustainable reservoir operation and river management in wider cryospheric regions under future climate and hydrological change.
DOI: adi5019
Source: https://www.science.org/doi/10.1126/sciadv.adi5019