基于GridMet模型的浙江省温湿指数空间分布及地形影响分析

温湿指数是气候舒适度评价模型之一,通过温度与湿度的组合反映人体与周围环境的热量交换,本文利用2003-2018年浙江省及其周边71个气象站点月平均气温、地面水汽压数据,以及MODIS水汽产品,基于GridMet模型模拟了浙江省各月温湿指数空间分布（100 m×100 m）,分析了浙江省温湿指数随地形因子（海拔、坡度、坡向）变化的特征;讨论了各地形因子对温湿指数空间分布的影响程度。结果表明：① 海拔、坡度、坡向3个地形因子中,1月温湿指数随坡向的变化最大,7月最小;② 同坡向上,坡度变化对1月温湿指数影响较大,而海拔变化则是对7月影响最大;③ 南坡1月温湿指数随海拔和坡度增加均略为增加,南坡其他月份及北坡各月均为随海拔和坡度增加温湿指数减小;④ 北坡相对于南坡而言,海拔和坡度对温湿指数的影响更为明显。浙江大部分山区由于地形影响,夏季较为“舒适”,适宜建立避暑消夏的旅游项目。

Spatial Distribution of THI in Zhejiang Province based on the GridMet Model

The temperature and humidity index is one of the climate comfort evaluation models, which reflects the heat exchange between human body and the surrounding environment through the combination of temperature and humidity.Based on the GridMet model, the spatial distribution of temperature and humidity indices(THI)in ZhejiangProvince(100 m×100 m)weresimulated by using monthly average air temperature, relative humidity from 71 meteorological stations, and MODIS 05over Zhejiang and surrounding areas during 2003-2018. Furthermore, we analyzed the distribution characteristics of THI in Zhejiang with the terrain factors (elevation, gradient, slope direction). The influence of terrain factors on the spatial distribution of the THIwas discussed. The results show that most montane areas in Zhejiang were more comfortable in summer due to the topographic influence, and thus, are suitable for establishing summer tourism projects. Specifically, among the three topographic factors of elevation, slope, and aspect, the THI in January changed the most with the slope direction and the least in July.On the same slope, the change of slope degree had a greater impact on the THI in January, while the change of altitude had the greatest impact in July. The THI in January on the south slope increased slightly with the increase of elevation and slope degree, while in other months on the south slope and on the north slopeTHI increased slightly with the elevation, and the sum of the THI decreased with the increase of slope gradient. Compared with the south slope, the influences of elevation and slope gradient on THIwere more obvious on the north slope.