Abstract:
[Objective] To study the evolution of river patterns in the distributive fluvial system, establish a database of corresponding parameters, and provide a data basis for predicting the distribution of sedimentary systems within the forecast basin, [Methods] Using modern geographic information software such as Google Earth and Global Mapper, the channel sinuosity was measured according to the grid of equal proportions, analyzes the variation of the channel sinuosity along the course, and establishes the depositional mode of the evolution of the Golmud fluvial fan. [Results and Discussions] A total of 2989 channel sinuosity data were measured, and according to the characteristics of the sinuosity of the Golmud fluvial fan, the Golmud fluvial fan can be divided into four parts: "braided river section", "braided-meander coexistence section", "large high-sinuosity meandering river section" and "small low-sinuosity meandering river section": 1) The slope of the braid river section was 0.7%, the development of the straight river and the braided river with low sinuosity, the braided belt width was large, the channel sinuosity was 1.01-1.43, the average sinuosity was 1.08, and the microfacies such as braided river, abandoned river and flood plain were mainly developed; 2) The slope of the braided-meander coexistence section was 0.63%, which developed both braided river and meandering river, and the development degree and river sinuosity of braided river and meandering river in different positions were different, the channel sinuosity was 1.08-5, and the average sinuosity was 1.52, and microfacies such as braided river, meandering river, abandoned river, crevasse splay, sand dunes and flood plain were mainly developed; 3) The slope of the large high-sinuosity meandering river section was 0.29%, mainly developed large meandering river, the channel was wide, the river bend swing was large, the channel sinuosity was 1.12-5, the average sinuosity was 1.83, and the microfacies such as meandering river, abandoned river, sand dunes and flood plain were mainly developed; 4) The slope of the small low-sinuosity meandering river section was 0.08%, mainly developed small bifurcated meandering river, narrow channel, small river bend swing, the channel sinuosity was 1.07-3.13, the average sinuosity was 1.51, and microfacies such as meandering river, abandoned river, crevasse splay, sand dunes and flood plain were mainly developed. [Conclusions] The depositional model of river-type evolution of macroDFS was established, which provided new knowledge base information for the prediction of the distribution of underground sedimentary systems.