How urbanization affects pan evaporation in China?

Pan evaporation (Epan) is widely considered as an important indicator of climate change. Previous studies have mainly focused on the influence of climate change on Epan. In recent 30 years, China has experienced rapid urbanization. However, the effects of urbanization on Epan have not been well understood. In this study, we used the PenPan model to reconstruct the Epan at meteoro-logical stations in China from 1985 to 2017. We compared the differences in Epan at the urban station and adjacent rural station in 29 pairs. The results suggest that urbanization increased annual Epan at urban stations by approximately 50-200 mm compared with rural stations. It also suggests that urbanization tended to enhance the trend in Epan at meteorological stations in the rapid urbanization period. The increase in vapor pressure deficit and air temperature caused by urbanization dominated the differences in Epan between the urban and rural stations. The results of this study highlight the importance for considering the impact of urbanization on Epan when investigating the atmosphere water demand or driving hydrological models using Epan at mete-orological stations in China.

Automated summary

This study reconstructed the Epan at meteorological stations in China from 1985 to 2017 using the PenPan model, and compared the differences in Epan between urban and adjacent rural stations. The results showed that urbanization increased the annual Epan at urban stations by approximately 50-200 mm compared with rural stations. Urbanization also tended to enhance the trend in Epan during the rapid urbanization period. The increase in vapor pressure deficit and air temperature caused by urbanization was the main reason for the differences in Epan between urban and rural stations.