中文摘要：

针对现有水系高程提取方法存在效率低、精度不高以及高程逻辑错误等问题，提出了一种基于等高线的水系高程提取方法。该方法通过构建水系与等高线的协同空间关系提高求交效率，采用河流分段趋势面插值方法提高水系高程精度，并建立水系树结构以避免高程逻辑错误。通过与现有方法的对比分析与试验验证，结果表明，该方法能兼顾精度与效率，且不存在高程逻辑错误，比现有方法更优。

英文摘要：

Considering the existing problems in methods of water system elevation extraction such as low efficiency, low accuracy, elevation logic errors and other issues, this paper proposes a method of water system elevation extraction based on contour line. Firstly, the cooperative spatial relationship between the water system and contour is constructed to improve the intersection efficiency in the method. Secondly, the accuracy of water system elevation can be improved and river flow logical error can be avoided by using the method of interpolation of trend surface of the river section. And then, a tree structure of water system is established to avoid river confluence reaches logical error of water system. In the last, there are many experiments about contrast among algorithm efficiency, elevation accuracy and elevation logical error between this method and other two conventional methods. The result of experiments shows that both accuracy and efficiency can be improved and there is no logical error of elevation by using this method.