Planform geometry characteristics of typical meandering rivers in Yellow River Source

The Baihe and Heihe rivers are tributaries in the Yellow River source region in the north-eastern part of the Qinghai-Tibet Plateau.The rivers are meandering with extremely high sinuosity and numerous oxbow lakes.Digital Elevation Model and Google Earth satellite images are used for analyzing the characteristics of the rivers,meanders and oxbow lakes.River networks and longitudinal bed profiles of the Baihe and Heihe rivers are extracted by using GIS model.Channel width,sinuosity,valley width and number of oxbow lakes are calculated with AutoCAD software.Average sinuosity of the Heihe River is 2.46,which is much greater than that of the Baihe River(1.68).It is found that the sinuosity of the Heihe river is greater than the Baihe River and the main causes for the big difference are their different average flow discharges and average channel gradients.The Heihe River has much higher density of oxbow lakes than the Baihe River.The density of oxbow lakes of the Heihe River is more uniform along the course which keeps a higher frequency of cutoffs.The density of oxbow lakes reduces along the course of the Baihe River because the channel width and average flow discharge increase along the course.