An Observational Study on the Local Climate Effect of the Shangyi Wind Farm in Hebei Province

Abstract

Zhangjiakou is an important wind power base in Hebei Province, China. The impact of its wind farms on the local climate is controversial. Based on long-term meteorological data from 1981 to 2018, we investigated the effects of the Shangyi Wind Farm (SWF) in Zhangjiakou on air temperature, wind speed, relative humidity, and precipitation using the anomaly or ratio method between the impacted weather station and the non-impacted background weather station. The influence of the SWF on land surface temperature (LST) and evapotranspiration (ET) using MODIS satellite data from 2003 to 2018 was also explored. The results showed that the SWF had an atmospheric warming effect at night especially in summer and autumn (up to 0.95°C). The daytime air temperature changes were marginal, and their signs were varying depending on the season. The annual mean wind speed decreased by 6%, mainly noted in spring and winter (up to 14%). The precipitation and relative humidity were not affected by the SWF. There was no increase in LST in the SWF perhaps due to the increased vegetation coverage unrelated to the wind farms, which canceled out the wind farm-induced land surface warming and also resulted in an increase in ET. The results showed that the impact of wind farms on the local climate was significant, while their impact on the regional climate was slight.

摘 要

河北张家口地区作为中国重要的风电基地, 关于其风电场对局地气候的影响尚存在诸多争议. 本研究利用张家口地区的尚义风电场及周边地区 1981–2018 年国家气象站观测资料和 2003–2018 年 MODIS 陆表温度 (LST)、 陆表蒸散 (ET) 和归一化植被指数 NDVI 等卫星观测数据, 分别采用背景气象站对比法、 区域距平法、 影响区-非影响区差值法开展了尚义风电场的局地气候效应 (气温、 风速、 相对湿度、 降水量、 LST 和 ET) 研究. 研究结果显示: 风电场具有增暖效应, 其中年均气温和年最低气温分别增加 0.37 °C 和 0.81 °C, 增暖主要发生在夜晚, 秋季夜晚和夏季夜晚分别增温 0.95 °C 和 0.93 °C; 而白天没有明显增温现象; 年均风速降低 6%, 且主要发生在春季和冬季, 分别降低 14% 和 8%. 风电场对降水量没有明显影响; 相对湿度和 ET 的增加很可能是由于风电场所在区域 NDVI 增加造成; LST 并没有表现增暖现象, 这很可能是由于 NDVI 增加导致 LST 降低、 从而抵消了风电场对 LST 的增暖效应. 本文研究结果确认了张家口风电场的局地增暖和风速降低效应, 同时分析也表明风电场对区域气候并没有明显影响, 这对未来该地风电发展具有参考意义.