Channel hydraulics data and grain sizes of the seven studied rivers in the Qilian Shan.docx

From the fan apex to the distal end, our field investigations included measurements of channel geometry, channel gradient, sediment grain size, and geomorphic characteristics along the channel. The channel gradient for each channel was calculated from the longitudinal profiles obtained from the SRTM DEM (30-m resolution). The depths were obtained by averaging the values measured at 1-m intervals across the bank-full channels. Grain sizes were measured by pebble counting (Wolman, 1954), based on 100 stochastically selected pebbles on the active channel bed.从扇顶至远端，本次野外调查涵盖沿河道的河道几何形态、河道坡度、沉积物粒度及河道地貌特征的测量工作。各河道的坡度通过基于航天飞机雷达地形测绘任务数字高程模型（SRTM DEM，30米分辨率）获取的纵剖面计算得到。河道水深通过对满岸河道内以1米间隔采集的测量值取平均获得。沉积物粒度采用砾石计数法（Wolman, 1954）测定，采样样本为活动河道床面上随机选取的100颗砾石。