Spatio-temporal variations in dew and its relevance to drought in the Beijing-Tianjin-Hebei region of China

Abstract

ABSTRACT The long-term trend and its spatio-temporal characteristics of dew formation over the Beijing-Tianjin-Hebei (BTH) region are still poorly understood. We examined dew and its climatic controls in BTH from 2008 to 2021 over China with the aid of model estimation based on the atmospheric data from the China Meteorological Administration Land Data Assimilation System (CLDAS). Besides, the relevance of dew to drought was also examined. Dew amount showed a decreasing tendency from northwest to southeast over BTH for the 14 years. The average monthly accumulative dew amount ranged from 0.56 mm to 15.87 mm. The annual dew amount was highest in Bashang and lowest in Plain area. Precipitation(P), air temperature (Ta) and relative humidity (RH) all showed positive correlation with dew over the three ecoregions, and among these, RH showed the most significant correlation with dew. The BTH showed a drier trend over the study period and dew exhibited higher over the dry area. Our study can not only provide a novel understanding of dew characteristics in the BTH, but also have an important potential effect on the water resources management in the context of climate change exacerbation.