水电能源科学

山坡壤中流过程是流域水文循环的重要组成,其响应特征受关键带结构的显著调控。为深入揭示不同山坡结构特征下壤中流及其流量过程的响应规律,基于山坡蓄量运动波方程,构建了不同坡度、剖面形状、平面形状的24种理想山坡,系统分析不同降雨强度下山坡壤中流水深剖面分布及流量过程。结果表明,坡度是控制系统稳定时间的主导因素,陡坡稳定时间约为缓坡的60%;剖面形状显著影响壤中流空间分布,凹形剖面的稳定水深整体高于直形与凸形,凸形剖面排水能力最强;平面形状主要调控坡脚水文响应,收敛型与高斯型山坡坡脚稳定水深约为发散型和平行型的2倍,而发散型山坡对坡脚流量过程变化最为敏感。研究结果揭示了山坡关键带结构特征对山坡壤中流及流量过程的调控机制,为深化复杂山坡产流机理认知及无资料区水文模拟提供了理论支撑。

Hillslope subsurface flow processes constitute a vital component of watershed hydrological cycles, and their response characteristics are significantly regulated by critical zone structures. To further reveal the response laws of subsurface flow and its discharge processes under varying hillslope structural features, this study established 24 idealized hillslopes with different gradients, profile shapes and planar shapes based on the hillslope storage kinematic wave equation. The distribution of water depth profiles and discharge processes of hillslope subsurface flow under diverse rainfall intensities were systematically analyzed. The results indicate that the slope gradient serves as the dominant factor controlling the system stabilization time, and the stabilization time of steep slopes is approximately 60% of that of gentle slopes; Profile shape exerts a remarkable influence on the spatial distribution of subsurface flow. The steady water depth of concave profiles is generally higher than that of straight and convex profiles, and convex profiles possess the strongest drainage capacity; Planar shape primarily regulates the hydrological response at the hillslope toe. The steady water depth at the toe of convergent and Gaussianshaped hillslopes is nearly twice that of divergent and parallel hillslopes, while divergent hillslopes are most sensitive to the variations in discharge processes at the slope toe. This study clarifies the regulatory mechanisms of hillslope critical zone structural characteristics on hillslope subsurface flow and discharge processes, providing theoretical support for deepening the understanding of runoff generation mechanisms on complex hillslopes and hydrological simulation in ungauged basins.