Abstract:Baihetan Hydroelectric Power Station is located in the canyon area of the lower reaches of the Jinsha River, with frequent northerly strong wind weather in the dry season. Objectively identifying the circulation system that affects the strong winds of the hydroelectric power station is beneficial for revealing the formation mechanism of strong winds in special areas. Based on 139 cases of northerly strong wind weather in the dry season in the canyon area from November to April of 2018-2020, this paper analyzes the circulation situation of strong wind weather, and establishes objective identification conditions with reference to the Lamb-Jenkinson (L-J) method. Moreover, the identification conditions are tested and corrected. The results show that 15 cases of typical northerly strong winds at the hydropower station are selected. According to the analysis of the characteristics of circulation situation, the upper-air circulation affecting strong winds is summarized as southern branch trough, plateau trough and transverse trough. In the 15 cases, the first two types appeared 6 times each and the transverse trough type appeared 3 times. Based on the analysis of circulation characteristic parameters by L-J method, the key areas and preliminary identification conditions of strong wind circulation in dry season are determined. The identification conditions of the southern branch trough and plateau trough types are that the zonal component u of the geostrophic wind in the key area is greater than 10 dagpm/10°longitude-1, and its difference from the meridional component v is greater than 10 dagpm/10°longitude-1. At the same time, the vorticity of the geostrophic wind is greater than 0 dagpm/10°longitude-1. The identification condition of transverse trough type is that the critical area u is less than 20 dagpm/10°longitude-1, and it is required to be greater than u. In addition, 14 cases of strong winds in the dry season of 2021 are selected to test the above circulation identification conditions. It is found that from 11 of the 14 cases, the circulation types are identified accurately. According to the reason that the circulation type is not recognized, the thresholds of u and the difference between u and v are corrected. The results show that the corrected discrimination conditions are accurate and feasible. The objective identification method of circulation situation could provide a reference for strong wind warning at the Baihetan Hydroelectric Power Station.