Runoff erosion response associated with sediment transport as influenced by erosive energy variability is a highly scale‐dependent process. Identifying the spatial scale effect on erosive runoff energy is important to understand the spatial pattern of sediment flow behavior across various sites. This issue was resolved by establishing thresholds for erosive runoff based on frequency analysis, which considered four selected threshold parameters: runoff duration (T), stream power (ω), stream energy factor (SE), and area‐specific sediment yield (SSY). Based on these thresholds, 77 erosive events were identified and separated from nonerosive events for further analysis of energy–sediment relationships. The threshold for T was roughly constant at hillslopes but rapidly increased at the entire slope. Thresholds for ω and SE exhibited positive linear relationships with the plot area, whereas the threshold for SSY showed a general increasing trend along the downslope direction. The R2 values of erosive energy–sediment relationships at inter‐ and intra‐event time scales were generally higher for erosive events than for nonerosive events. The sediment delivery capacity (Cd) for erosive runoff ranged from 0.075 to 0.115 kg·m·J−1. It demonstrated an initial increase followed by a subsequent decrease from the upper hillslope to the entire slope. Conversely, Cd for nonerosive runoff increased with the rise in plot area, and it ranged from 0.053 to 0.083 kg·m·J−1. The sediment‐increasing capacity (Ci) for erosive runoff ranged from 0.43 to 4.47 kg·m−2·W−1, whereas Ci for nonerosive runoff varied from 3.39 to 17.6 kg·m−2·W−1. The sediment reduction benefit by regulation unit stream energy factor varied from 5% at the entire slope to 65% at the upper hillslope. Therefore, anti‐erosion measures should be implemented at the upper hillslope to prevent nonerosive runoff from becoming erosive runoff.

中文翻译：

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空间尺度对黄土斜坡侵蚀径流和沉积物流动行为的影响：侵蚀能量基础


受侵蚀能量变化影响的与沉积物输送相关的径流侵蚀反应是一个高度依赖于尺度的过程。确定空间尺度对侵蚀径流能量的影响对于了解不同地点沉积物流动行为的空间模式非常重要。这个问题是通过基于频率分析建立侵蚀径流阈值来解决的，该分析考虑了四个选定的阈值参数：径流持续时间 （T）、溪流功率 （ω）、溪流能量因子 （SE） 和特定面积沉积物产量 （SSY）。根据这些阈值，确定了 77 个侵蚀事件并将其与非侵蚀事件分开，以进一步分析能量-沉积物关系。T 的阈值在山坡上大致恒定，但在整个斜坡上迅速增加。ω 和 SE 的阈值与绘图区呈正线性关系，而 SSY 的阈值沿下坡方向呈总体增加趋势。侵蚀事件在事件间和事件内时间尺度上的侵蚀能量-沉积物关系的 R2 值通常高于非侵蚀事件。侵蚀径流的沉积物输送能力 （Cd） 范围为 0.075 至 0.115 kg·m·J−1。它表现出最初的增加，然后随后从上部山坡下降到整个斜坡。相反，非侵蚀性径流的 Cd 随着地块面积的增加而增加，范围为 0.053 至 0.083 kg·m·J−1。侵蚀径流的沉积物增加能力 （Ci） 范围为 0.43 至 4.47 kg·m−2·W−1，而非侵蚀性径流的 Ci 在 3.39 到 17.6 kg·m−2·W−1.调节单位流能量因子减少沉积物的好处从整个斜坡的 5% 到上部山坡的 65% 不等。 因此，应在上部山坡实施防侵蚀措施，以防止非侵蚀性径流变成侵蚀性径流。