Journal of Resources and Ecology ›› 2018, Vol. 9 ›› Issue (5): 538-544.DOI: 10.5814/j.issn.1674-764x.2018.05.011

• Resources and Ecology in the Qinghai-Tibet Plateau • Previous Articles     Next Articles

Estimation of Daily Vapor Pressure Deficit Using MODIS Potential Evapotranspiration on the Tibetan Plateau

SHEN Zhenxi1, SUN Wei1, LI Shaowei1, ZHANG Haorui1,2, FU Gang1,*, YU Chengqun1, ZHANG Guangyu1,3,4   

  1. 1. Lhasa Plateau Ecosystem Research Station, Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China;
    2. University of Chinese Academy of Sciences, Beijing 100049, China;
    3. College of Resources and Environmental Sciences, China Agricultural University, Beijing 100193, China;
    4. Tibet Agriculture and Animal Husbandry University, Linzhi, Tibet 860000, China
  • Received:2018-01-18 Revised:2018-04-28 Online:2018-09-30 Published:2018-09-30
  • Contact: * FU Gang, E-mail: fugang@igsnrr.ac.cn
  • Supported by:
    National Key Research and Development Program of China (2017YFA0604801; 2016YFC0502006), National Natural Science Foundation of China (41571042; 31600432), Chinese Academy of Science Western Light Talents Program (Response of livestock carrying capability to climatic change and grazing in the alpine meadow of Northern Tibetan Plateau), the Youth Innovation Research Team Project of Key Laboratory of Ecosystem Network Observation and Modeling (LENOM2016Q0002), Natural Science Foundation of Tibet Autonomous Region (Response of species richness and above-ground biomass to warming in the alpine meadow of Tibet) and Science and Technology Plan Projects of Tibet Autonomous Region (Forage Grass Industry).

Abstract: Vapor pressure deficit (VPD) is an important parameter in modelling hydrologic cycles and vegetation productivity. Meteorological stations are scarce in remote areas, which often results in imprecise estimations of VPD on the Tibetan Plateau. Moderate Resolution Imaging Spectroradiometer (MODIS) provides evapotranspiration data, which may offer the possibility of scaling up VPD estimations on the Tibetan Plateau. However, no studies thus far have estimated VPD using MODIS evapotranspiration data on the Tibetan Plateau. Therefore, this study used MODIS potential evapotranspiration (PET) to estimate VPD in alpine meadows, alpine steppes, croplands, forests and shrublands for the year, spring, summer, autumn and winter in 2000-2012. A series of root-mean- squared-error (RMSE) and mean-absolute-error (MAE) values were obtained for correlating measured VPD and estimated VPD using MODIS PET data for each listed time period and vegetation type: whole year (0.98-2.15 hPa and 0.68-1.44 hPa), spring (0.95-2.34 hPa and 0.72-1.54 hPa), summer (1.39-2.60 hPa and 0.89-1.96 hPa), autumn (0.78-1.93 hPa and 0.56-1.36 hPa), winter (0.48-1.40 hPa and 0.36-0.98 hPa), alpine steppes (0.48- 1.39 hPa and 0.36-1.00 hPa), alpine meadows (0.58-1.39 hPa and 0.44-0.90 hPa), croplands (1.10-2.55 hPa and 0.82-1.74 hPa), shrublands (0.98-1.90 hPa and 0.78-1.37 hPa), and forests (1.40-2.60 hPa and 0.98-1.96 hPa), respectively. Therefore, MODIS PET may be used to estimate VPD, and better results may be obtained if future studies incorporate vegetation types and seasons when the VPD data are estimated using MODIS PET on the Tibetan Plateau.

Key words: alpine ecosystems, MOD16A2, seasons, vegetation types