Temporal variations of reference evapotranspiration and controlling factors:Implications for climatic drought in karst areas  

作　　者：Xiao-jiao Guo Wen-zhong Wang Cheng-xi Li Wei Wang Jian-sheng Shi Ying Miao Xing-bo Hao Dao-xian Yuan 

机构地区：[1]Key Laboratory of Groundwater Sciences and Engineering,Ministry of Natural Resources,Institute of Hydrogeology and Environmental Geology,Chinese Academy of Geological Sciences,Shijiazhuang 050061,China [2]Ecogeological Survey Center of China Geological Survey,China Aero Geophysical Survey and Remote Sensing Center for Natural Resources,Beijing 100083,China [3]China University of Geosciences(Wuhan),Wuhan 430074,China [4]Key Laboratory of Karst Dynamics,Institute of Karst Geology,Chinese Academy of Geological Sciences,Guilin 541004,Guangxi,China [5]Geological Exploration Institute of Shandong Zhengyuan,China Metallurgical Geology Bureau,Jinan 250101,China [6]Hebei Coal Geology Bureau fourth Geological Brigade,Zhangjiakou 075100,Hebei,China.

出　　处：《Journal of Groundwater Science and Engineering》2022年第3期267-284,共18页地下水科学与工程（英文版）

基　　金：supported by the Fundamental Research Funds for Central Public Welfare Research Institutes,CAGS(SK202208,SK202209,SK202005,SK202009);China Geological Survey Project(DD20221752)。

摘　　要：Variations in reference evapotranspiration(ET_(0)) and drought characteristics play a key role in the effect of climate change on water cycle and associated ecohydrological patterns.The accurate estimation of ET_(0) is still a challenge due to the lack of meteorological data and the heterogeneity of hydrological system.Although there is an increasing trend in extreme drought events with global climate change,the relationship between ET_(0) and aridity index in karst areas has been poorly studied.In this study,we used the Penman-Monteith method based on a long time series of meteorological data from 1951 to 2015 to calculate ET_(0)in a typical karst area,Guilin,Southwest China.The temporal variations in climate variables,ET_(0)and aridity index(AI)were analyzed with the Mann-Kendall trend test and linear regression to determine the climatic characteristics,associated controlling factors of ET_(0) variations,and further to estimate the relationship between ET_(0) and AI.We found that the mean,maximum and minimum temperatures had increased significantly during the 65-year study period,while sunshine duration,wind speed and relative humidity exhibited significant decreasing trends.The annual ET_(0) showed a significant decreasing trend at the rate of−8.02 mm/10a.However,significant increase in air temperature should have contributed to the enhancement of ET_(0),indicating an“evaporation paradox”.In comparison,AI showed a slightly declining trend of−0.0005/a during 1951-2015.The change in sunshine duration was the major factor causing the decrease in ET_(0),followed by wind speed.AI had a higher correlation with precipitation amount,indicating that the variations of AI was more dependent on precipitation,but not substantially dependent on the ET_(0).Although AI was not directly related to ET_(0),ET_(0)had a major contribution to seasonal AI changes.The seasonal variations of ET_(0)played a critical role in dryness/wetness changes to regulate water and energy supply,which can lead to seasonal droughts or water

关 键 词：Reference evapotranspiration Aridity index Penman-Monteith method Sunshine duration GUILIN 

分 类 号：P426.616[天文地球—大气科学及气象学]