Horizontal displacement monitoring is an important item of dam safety monitoring, which has many monitoring methods. The current specification of dam monitoring has a general regulation on the deformation direction of horizontal displacement. In practice, the observation coordinates used in different methods for horizontal displacement monitoring are quite different, which often causes inconvenience, even errors, in the comparative analysis of horizontal displacement. The paper discusses the method and principle of the unification of observation coordinates for horizontal displacement monitoring projects of dams and slopes in Yalong river basin. By popularizing and applying in the basin, the efficiency of dam safety monitoring data analysis has been greatly improved, which provides reference for the revision of relevant specifications and the practices of other electric power enterprises. As well, it promotes the standardized and refined dam safety management.

horizontal displacement monitoring, coordinate unification, conversion angle, arch dam, slope

水平位移监测是大坝安全监测重要项目之一，监测方法众多。现行大坝监测规范对水平位移变形方向规定较笼统，在实际应用中，不同水平位移监测手段采用的观测坐标差异较大，往往给水平位移对比分析造成诸多不便，甚至错误。笔者探讨了雅砻江流域大坝及边坡水平位移监测项目观测坐标统一的方法和原则，通过在流域推广应用，极大地提高了流域统筹大坝安全监测资料分析工作的效率，为后续相关规范修编及其他电力企业应用提供借鉴和参考，促进运行单位大坝安全管理工作的规范化、精细化。

水平位移监测, 坐标统一, 转换角度, 拱坝, 边坡