基于高分辨率再分析资料的西南地区风资源特征分析

Analysis of Wind Resources in Southwest China based on High-resolution Reanalysis Data

为评估高分辨率再分析近地层风速资料在西南地区的适用性,得到西南地区风资源基本时空分布特征,采用2015-2019年欧洲中期数值天气预报中心ERA5再分析资料和西南地区42个气象台站逐日10 m风速观测资料,利用幂律推导、误差分析和双参数Weibull概率分布等方法对ERA5再分析资料在西南地区的适用性以及西南地区风能资源时空分布特征进行分析。结果表明:尽管ERA5再分析资料整体上对西南地区近地面风速有所低估,但区域平均偏差仅为0.27 m/s,多数地区再分析资料与气象台站实测10 m风速之间存在较好的相关性,风速概率拟合也具有较好的一致性,表明ERA5再分析资料可用于西南地区风资源分析。西南地区风速概率分布也存在明显的地域差异,其中四川盆地与周边山地交界地区弱风累积概率明显高于四川盆地、贵州大部、川西高原西北部和云南中东部。同时,西南地区大部分区域风资源较为匮乏,但云南中部和川西北高原属风资源可利用区,其平均风速、最大概率风速、风能最大风速、风功率密度和年有效风时数等风能指标相对其他区域更优。

In order to evaluate the applicability of high-resolution reanalysis near-ground wind speed data in Southwest China and obtain the basic temporal and spatial distribution characteristics of wind resources in Southwest China,based on the ERA5 reanalysis data of European medium-range numerical Weather Forecast Center from 2015 to 2019 and the daily wind speed observation data of 42 meteorological stations in Southwest China,it is studied by means of power law derivation,error analysis and two-parameter Weibull probability distribution.In response to the problem that reanalysis data is rarely applied in wind resource assessment in the southwest China.The characteristics of the 100 m wind resources of southwest China were assessed using power-lawerror analysis,and two-parameter Weibull probability distribution based on ERA5 hourly reanalysis and daily observed wind speed of meteorological stations.The results show that although the ERA5 reanalysis data underestimate the near-surface wind speed in southwest China as a whole,the regional average deviation is only 0.27 m/s.There is a good correlation between the reanalysis data of most areas and the wind speed of 10 m measured by meteorological stations,and the probability fiing of wind speed is also in good agreement,indicating that the ERA5 reanalysis data can be used to analyze the wind resources in southwest China.the regional average deviation between ERA5 and the measured wind speed of meteorological stations is only 0.273m/s,the correlation coefficient exceeds 0.4 in more than 67.7%between the observation and ERA5,and the RMSE is small at most stations.On the other hand,the wind speed probability distribution is good agreement between the reanalysis data and observation,ERA5 can be used for southwest wind resource assesment.The spatial distribution of Weibull shape and scale indicate the probability distribution of wind speed is significant differences in southwest China,the cumulative probability of small wind speed in Sichuan Basin to high-altitude transition area is larger than that in Sichuan Basin,most area of Guizhou,Hengduan Mountain and central and eastern Yunnan.In addition,the average wind speed,maximum probable wind speed,the speed of maximum wind energy,wind power density and annual effective hours of wind speed show that wind resources are scarce in most areas of southwest China,but the Yunnan-Guizhou Plateau and the northwestern part of the Sichuan-Western Plateau are wind resource-available areas.