Welcome to Chinese Journal of Applied Ecology! Today is Share:

Chinese Journal of Applied Ecology ›› 2017, Vol. 28 ›› Issue (8): 2563-2568.doi: 10.13287/j.1001-9332.201708.015

• CONTENTS • Previous Articles     Next Articles

Dew condensation time and frequency in the loess hilly region of Ansai County, northern Shaanxi Province, China

WANG Hao1,2, JIA Zhi-feng1,2,3, LU Yu-dong1,2, HE Zi-li4, WANG You-ke4,5, CHEN Yun-ming5, WANG Zhi1,2,3,4,6*   

  1. 1College of Environmental Science and Engineering, Chang’an University, Xi’an 710054, China
    2 Ministry of Education Key Laboratory of Subsurface Hydrology and Ecological Effects in Arid Region, Xi’an 710054, China
    3Research Institute of Water and Development, Chang’an University, Xi’an 710054, China
    4College of Water Resources and Architectural Engineering, Northwest A&F University, Yangling 712100, Shaanxi, China
    5Soil and Water Conservation and Ecological Environment Research Center, Chinese Academy of Sciences and Ministry of Water Resources, Yangling 712100, Shaanxi, China
    6Department of Earth and Environmental Sciences, California State University, Fresno, California 93740, USA.
  • Received:2016-12-26 Published:2017-08-18
  • Contact: * E-mail: zwang@csufresno.edu
  • Supported by:
    This work was supported by the“111”Intellectual Importation Project (B08039),the Fundamental Research Funds for the Central Universities (310829161003) and the Houji Scholar Special Funds from Northwest A&F University (Z111021003)

PDF (PC)

141

Abstract: Dew condensation time and frequency are basic parameters for exploring the vapor phase of water resources. According to an in-situ monitoring of near-surface dew occurrence between 2015 and 2016 in a typical loess hilly region of Ansai County, Shaanxi Province, the dew condensation time, frequency and their atmospheric influencing factors were analyzed. Results showed that the dew condensation time was long and occurred in cyclic patterns. Over the daily cycle, dew manifested a typical “night-time show and day-time no-show” pattern, and it mainly occurred between 21: 00 and 8: 00 while the most frequently condensed dew period was between 4:00 and 6:00. Over the seasonal cycle, summer and fall had the higher frequency, whereas spring and winter had the lower frequency. Over the annual cycle, the most frequent dew period was from June to November. Compared to rainfall, dewfall had characteristics of higher frequency and stronger stability. A variety of substrate and meteorological factors contributed to the formation of dew, e.g. dew occurred more frequently when the atmospheric relative humidity was greater than 80%, air temperature-dew point difference was between 1 and 3 ℃, and wind speed was between 0 and 1 m·s-1. In Ansai, wind directions ranging among 120°-150° and 240°-300° were more favorable to dew condensation.