Reference evapotranspiration under changing climate over the Thar Desert in India

Meteorological applications

article

D. Jhajharia¹  R. Kumar²  P. P. Dabral¹  V. P. Singh³  R. R. Choudhary⁵  Y. Dinpashoh⁶ 

[1] Department of Agricultural Engineering, North Eastern Regional Institute of Science and Technology;Division of Agricultural Engineering, Sher-e-Kashmir University of Agricultural Sciences and Technology;Department of Biological and Agricultural Engineering, Texas A&M University, College Station;Department of Civil and Environmental Engineering, Texas A&M University, College Station;Department of Electronic Instrumentation and Control Engineering, Engineering College Bikaner;Department of Water Engineering, Faculty of Agriculture, University of Tabriz

关键词: evapotranspiration;    trend;    causal meteorological parameters;    Thar Desert;   

DOI  :  10.1002/met.1471

学科分类：社会科学、人文和艺术（综合）

来源: Wiley

【 摘 要 】

Reference evapotranspiration (RET) plays a critical role in irrigation planning and is needed for the determination of water demands of crops. Thus, in the present study, trends in RET were identified over Bikaner located in the Thar Desert (Rajasthan) in India using the non-parametric Mann–Kendall (MK) test. First, RET values were estimated through the Penman–Monteith method for different time scales using meteorological data for 39 years from 1967 to 2005. Second, the effect of significant lag-1 serial correlation was removed from the time series of RET by pre-whitening. Third, trends were investigated using the MK test. RET was found to decrease significantly at Bikaner during annual, pre-monsoon, monsoon and post-monsoon time scales. On probing the causal meteorological parameters responsible for the observed RET trends in the Thar Desert, it was witnessed that wind speed dynamically influenced the observed RET changes at the annual time scale and all the four seasons over the Thar Desert. The maximum temperature, followed by relative humidity, influenced the RET trends at annual and seasonal (winter, pre-monsoon and monsoon) time scales. The calm atmosphere witnessed over this arid site substantiates RET decreases over this Thar Desert site. The results of this study support that the evapotranspiration decreases over Bikaner are controlled mainly by trends in the aerodynamic component, i.e. by the effects of significant wind speed decreases on RET, than the changes in the radiative component over the arid site located in the Thar Desert.

【 授权许可】

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