DAI Minghong1, LI Yutao2, WANG Lachun1, ZENG Chunfen1, CHEN Hongyuan3
(1.School of Geographic and Oceanographic Sciences, Nanjing University, Nanjing 210023, China;
2. Jiangsu Meteorological Information Center, Nanjing 210028, China;
3. Puding Comprehensive Experiment station of Karst, Puding 562100, China)
Abstract: Water shortage problem is very serious in karst areas of the Southwestern China. Agricultural ecological environment is fragile and agricultural water is difficult to guarantee. Taking Guizhou Province as an example, based on the FAO-56 Penman-Monteith equation and meteorological data, the reference crop evapotranspiration (ETO) from 1961 to 2014 in Guizhou Province was estimated. The reference crop evapotranspiration was interpolated in the whole province by using IDW method and temporal and spatial variation of ETO were analyzed. Besides, the main factors influencing ETO in Guizhou Province were analyzed by using multiple regression analysis method. Results show that ETO in the west of Guizhou is higher than that in the eastern and middle part of the province. In a year, ETO is higher in summer and spring than that in autumn. ETO is the lowest in winter. ETO in 1960s was higher than the average. After 1970s, ETO was gradually decreasing, and reached the lowest value in 1990s. The annual ETO has risen sharply since 2000. The annual average ETO of Guizhou Province fluctuated in the overall upward trend. ETO had significantly decreased from 1961 to 2002, and after 2003, it has been in the upward trend. The variation rate of ETO in autumn is higher than that in spring and summer; the variation rate in winter is the lowest. The dominant factors of ETO are bright sunshine hours. Besides, geographical latitude is in significantly negative correlation with ETO. The research on spatial and temporal characteristics of ETO in Guizhou Province and its influencing factors will provide scientific basis for agricultural development and water resources allocation in other karst areas.
Key words: reference crop evapotranspiration(ETO); temporal and spatial variation; FAO-56 Penman-Monteith method; Karst
EARTH AND ENVIRONMENT Vol. 44, No.3 Tot No.311, 2016, Page 342-352
