Abstract: The accuracy of height measurement and control in hydraulic physical model is one of the key factors that directly affect the reliability of test results, the model height accuracy must satisfy the requirement of related code and the experimental task. Sometimes it is difficult to control accuracy in measuring height system of large - scale model by means of level instrument measurement method. According to the connecting pipe principle, the connection of the water level station and the height control point by connecting pipe and ancillary devices in the model will form a static level measurement system, meanwhile according to definite observation procedure and calculation method will increase the measurement accuracy. Through applying to the daily regulation model of the Three Gorges-Gezhouba project, the system has been proved to be characteristic of high precision, simple structure, convenient operation and maintenance, the method provides also a simple and reliable means for precision measurement in related domain.

Key words:  hydraulic model  ,   height measurement  ,   hydrostatic leveling system  ,   connecting pipe ,    settlement observation