Impact Analysis of Urbanization on Wind Speed and Relative Humidity in Xianning Area

Cheng Jiao; Ren Yongjian; Zhang Yan; Xu Yuanyuan

doi:10.16765/j.cnki.1673-7148.2017.04.008

Abstract：Annual and seasonal variation characteristics of relative humidity and wind speed in Xianning area are analyzed,and urbanization effects on wind speed and relative humidity are quantitative analyzed by UMR (Urban Minus Rural) and OMR (Observation Minus Reanalysis) methods,by using surface observation data and NCEP/NCAR reanalysis data in 1981-2014,and using satellite data to realize classification of urban and suburb stations,selecting Chibi as urban station and Chongyang as suburban station.The results show as follows.In recent 34 years,the wind speed in urban and suburban are decreasing in speed of-0.18 m · s-1/10a and-0.05 m · s-1/10a,the variation trend of UMR value (Urban Minus Rural anomaly difference) is-0.13 m · s-1/10a,corresponding urbanization contribution rate is 75％,while the impact of urbanization is the most obvious in summer,the contribution rate is 100％.In recent 34 years,the relative humidity in urban and suburban are decreasing in speed of -1.34％/10a and-2.49％/10a,while the decreasing trend in suburban is greater than in urban.In recent 10 years,the relative humidity in urban is beginning to excess that in suburban,the impact of urbanization on relative humidity transforms from "dry island effect" to" moisture island effect",and the " moisture island effect" is the most significant in summer.The variation trend of wind speed and relative humidity calculated by UMR method are in consistent with those by OMR method,but the result calculated by UMR method shows that the impact of urbanization on wind speed decreasing and relative humidity increasing are more obvious,which can reflect the impact of urbanization on wind speed and relative humidity in Xianning area better.