黄河源流域单元概念及其提取方法研究

针对黄河源高寒草地生态系统保护的流域属性与差异性，本研究提出了一种准确便捷的流域单元识别方法。以国产高分辨率遥感影像所提取水系矢量数据作为标准参照系，基于数字高程数据（Digital elevation model，DEM）汇流累积计算量阈值设置为30 000时所获取的水系信息与黄河源实际水系状况较为相近。通过合并集水区获取黄河源流域单元878个，其中干流单元1个，一级支流单元219个，二级支流单元420个，三级支流单元194个，四级支流单元21个，断流河流单元23个。受地形地貌影响黄河源流域单元中河流长度与流域面积差距较大。本研究完善了黄河源水系及流域单元特征信息，为黄河源生态治理工作提供参考。

The Study on the Concept and Extraction Method of the River Basin Units in the Source Region of Yellow River

This research proposed an accurate and convenient method for identifying the river basin unit in view of the basin attributes and differences of ecological protection on basis of the river basin unit in the source region of yellow river. The obtained water system information was similar to the actual water system condition of the source region of yellow river,when the threshold value of the confluence accumulation was set to 30 000 based on DEM data with the resolution better than 30 m,grounding on the water system vector data obtained from domestic high-resolution remote sensing images as the standard reference system. 878 units data in the source region of yellow river were obtained by merging catchment areas. Besides,there were 1 main stream unit,219 first-level tributary units,420 second-level tributary units,194 third-level tributary units,21 fourth-level tributary units,and 23 dry-flow river units. There were large differences in river length and basin area among different basin units due to the influence of topography and geomorphology. This research could improve the information on the water system and river basin units in the source region of yellow river. It could also provide references on ecological management for source region of yellow river.