Journal of Mountain Science

, Volume 13, Issue 2, pp 302–315

Trends in major and minor meteorological variables and their influence on reference evapotranspiration for mid Himalayan region at east Sikkim, India

  • Shweta Yadav
  • Proloy Deb
  • Sonn Kumar
  • Vanita Pandey
  • Pankaj Kumar Pandey
Article

DOI: 10.1007/s11629-014-3238-3

Cite this article as:
Yadav, S., Deb, P., Kumar, S. et al. J. Mt. Sci. (2016) 13: 302. doi:10.1007/s11629-014-3238-3
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Abstract

Estimation of evapotranspiration (ET) for mountain ecosystem is of absolute importance since it serves as an important component in balancing the hydrologic cycle. The present study evaluates the performance of original and location specific calibrated Hargreaves equation (HARG) with the estimates of Food and Agricultural Organization (FAO) Penman Monteith (PM) method for higher altitudes in East Sikkim, India. The results show that the uncalibrated HARG model underestimates ETo by 0.35 mm day−1 whereas the results are significantly improved by regional calibration of the model. In addition, this paper also presents the variability in the trajectory associated with the climatic variables with the changing climate in the study site. Nonparametric Mann-Kendall (MK) test was used to investigate and understand the mean monthly trend of eight climatic parameters including reference evapotranspiration (ETo) for the period of 1985 – 2009. Trend of ETo was estimated for the calculations done by FAO PM equation. The outcomes of the trend analysis show significant increasing (p ≤ 0.05) trend represented by higher Z-values, through MK test, for net radiation (Rn), maximum temperature (Tmax) and minimum temperature (Tmin), especially in the first months of the year. Whereas, significant (0.01 ≥ p ≤ 0.05) decreasing trend in vapor pressure deficit (VPD) and precipitation (P) is observed throughout the year. Declining trend in sunshine duration, VPD and ETo is found in spring (March – May) and monsoon (June – November) season. The result displays significant (0.01≤ p ≤ 0.05) decreasing ETo trend between (June – December) except in July, exhibiting the positive relation with VPD followed by sunshine duration at the station. Overall, the study emphasizes the importance of trend analysis of ETo and other climatic variables for efficient planning and managing the agricultural practices, in identifying the changes in the meteorological parameters and to accurately assess the hydrologic water balance of the hilly regions.

Keywords

Reference evapotranspiration (EToClimatic variables Trend analysis Mann-Kendall’s test Monthly variation East Sikkim hilly region 

Copyright information

© Science Press, Institute of Mountain Hazards and Environment, CAS and Springer-Verlag Berlin Heidelberg 2016

Authors and Affiliations

  • Shweta Yadav
    • 1
  • Proloy Deb
    • 2
  • Sonn Kumar
    • 3
  • Vanita Pandey
    • 4
  • Pankaj Kumar Pandey
    • 3
  1. 1.Water Engineering and ManagementAsian Institute of TechnologyPathumthaniThailand
  2. 2.Centre for Water, Climate and Land-Use (CWCL), Faculty of Science and Information Technology, School of Environmental and Life SciencesUniversity of NewcastleCallaghanAustralia
  3. 3.Department of Agricultural EngineeringNortheastern Regional Institute of Science and TechnologyNirjuliIndia
  4. 4.Department of Soil and Water EngineeringCollege of Agricultural Engineering and Post Harvest TechnologyRanipoolIndia

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