Accelerated glacier-snow-permafrost erosion due to global warming amplifies the sediment availability in cold environments and affects the time-varying suspended sediment concentration (SSC) and discharge (Q) relationship. Here, the sediment-availability-transport (SAT) model is proposed to simulate dynamic SSC-Q relationships by integrating the sediment availability coupled by thermal processes, fluvial processes and long-term storage exhaustion into a sediment rating curve (SSC = a × Q^b with a and b as fitting parameters). In the SAT-model, increased sediment sources from glacier-snow-permafrost erosion are captured by changes in basin temperature, showing an exponential amplification of SSC when basin temperature increases. Enhanced fluvial erosion by the elevated water supply from rainfall and meltwater is captured by the factor of runoff surge, which results in a linear amplification of SSC. The SAT-model is validated for the permafrost-dominated Tuotuohe basin on Tibetan Plateau utilizing multi-decadal daily SSC/Q in-situ observations (1985–2017). Results show that sediment rating curves for Tuotuohe display significant inter-annual variations. The higher parameter-b in a warmer and wetter climate confirms the increased sediment availability due to the expanded erodible landscapes and gullying-enhanced connectivity between channels and slopes. Through capturing such time-varying sediment availability, the SAT-model can robustly reproduce the long-term evolution, seasonality, and various event-scale hysteresis of SSC, including clockwise, counter-clockwise, figure-eight, counter-figure-eight, and more complex hysteresis loops. Overall, the SAT-model can explain over 75% of long-term SSC variance with stable performance under hydroclimate abrupt changes, outperforming the conventional and static sediment rating curve approach by 20%. The SAT-model not only advances understanding of sediment transport mechanisms by integrating thermal- and fluvial-erosion processes, but also provides a model framework to simulate and project future sediment loads in other cold basins.

中文翻译：

---

在寒冷环境中约束动态沉积物-排放关系：沉积物-可用性-运输 (SAT) 模型

全球变暖导致的冰川-雪-永久冻土侵蚀加速，会放大寒冷环境中的沉积物可用性，并影响随时间变化的悬浮泥沙浓度 (SSC) 和流量 ( Q ) 关系。在此，沉淀物可用性传输（SAT）模型，提出了以模拟动态SSC- Q通过集成耦合由热过程，河流过程和长期存储耗尽成沉积物评级曲线沉积物可用性（SSC =关系 一个× Q ^b与a和b作为拟合参数）。在 SAT 模型中，冰川-雪-永久冻土侵蚀增加的沉积物来源被盆地温度的变化捕获，表明当盆地温度升高时 SSC 呈指数放大。降雨和融水的供水量增加导致的河流侵蚀增强被径流浪涌因子捕获，从而导致 SSC 的线性放大。利用多年的每日 SSC/ Q原位观测（1985-2017）验证了 SAT 模型对于青藏高原上以多年冻土为主的沱沱河盆地。结果表明，沱沱河的泥沙分级曲线显示出显着的年际变化。较高的参数-b在温暖和潮湿的气候中，由于可侵蚀景观的扩大以及沟渠和斜坡之间的沟壑增强的连通性，沉积物的可用性增加。通过捕获这种随时间变化的沉积物可用性，SAT 模型可以稳健地再现 SSC 的长期演变、季节性和各种事件尺度滞后，包括顺时针、逆时针、八字形、反八字形、以及更复杂的磁滞回线。总体而言，SAT 模型可以解释超过 75% 的长期 SSC 方差，并在水文气候突然变化下表现稳定，比传统和静态沉积物评级曲线方法高出 20%。SAT 模型不仅通过整合热侵蚀和河流侵蚀过程促进了对沉积物输送机制的理解，