Analysis of Evaporation Characteristics in Nanjing City during 1985-2010

[Objective] The characteristics of the changes of evaporation in Nanjing City from 1985 to 2010 were expounded.[Method] By dint of the evaporation data of the E601B evaporator of Nanjing during 1985-2010,an investigation was performed to analyze the variation characteristics of Nanjing evaporation and the reasons based on linear regression,tendency analysis and anomaly analysis methods.[Result] Results showed that the annual and seasonal evaporation in Nanjing was increasing,especially the evaporation in spring,and followed by that in summer and autumn.The increasing evaporation tendency was indistinct in winter.And the annual evaporation variation was mainly caused by the changes of seasonal evaporation in spring and summer.The influential factors of evaporation variation included temperature,ground temperature,sunshine time,average wind speed,relative humidity,air pressure,precipitation,and so on.By means of the correlation analysis on the impact factors and evaporation,the evaporation was in positive relation with relevant humidity,temperature,and pressure and ground temperature.It had small relation with precipitation,sunshine hours and wind speed.Evaporation was the comprehensive effect of all kinds of meteorological elements.The relevance between evaporation and relevant humidity was the best.[Conclusion] The study provided theoretical basis for the analysis of water resources evaluation and climate changes.