Multi-tree coupling method of high resolution drainage network extraction on large-scale basin

The construction of large-scale distributed hydrological model is an important tool to reveal the global water cycle movement mechanism and the drainage network topological information is one of the most important basic inputs for it. However, it is hard to extract high resolution drainage network for the large-scale basin by each kind of software nowadays. A multi-tree coupling approach was put forward to solve the problem through the way of decomposition first and latter integration, which can acquire high resolution drainage network of the large-scale basin very effectively. The approach has high applicability and is not restricted by the basin scale and original data precision, and also, the corresponding drainage network extraction process could take full advantage of current various software platforms without any change. The multi-tree coupling approach was applied in the Lhasa River basin with area of 32000 km2 in Tibet, and realized a disposable integration of 9 sub-block drainage networks and achieved 147994 hill slope units with the average area of 0.22 km2. It demonstrated the technical feasibility of the multi-tree coupling approach and provided an important technical support for the continuous large-scale hydrological simulation.