Acta Geographica Sinica ›› 2004, Vol. 59 ›› Issue (1): 13-24.doi: 10.11821/xb200401002

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Monitoring and Simulation of Water, Heat and CO2 Fluxes in Various Terrestrial Ecosystems

WANG Qinxue1, WATANABE Masataka1, HAYASHI Seiji2, MURAKAMI Shogo3, OUYANG Zhu4, LI Yan4, LI Yingnian5   

  1. 1. National Institute for Environmental Studies, Tsukuba 305-8506, Japan;
    2. Institute of Geographic Sciences and Natural Resources Research, CAS, Beijing 100101, China;
    3. Xinjiang Institute of Ecology and Geography, CAS, Urumqi 830011, China;
    4. Northwest Plateau Institute of Biology, CAS, Xining 810008, China;
    5. Institute of Subtropical Agricultural Ecology, CAS, Changsha 410125, China
  • Received:2003-09-07 Revised:2003-11-26 Online:2004-01-25 Published:2004-01-25
  • Supported by:

    Integrated Environmental Monitoring (IEM) Subproject, the Asia-Pacific Environmental Innovation Strategy Project (APEIS)

Abstract:

Water vapor, heat and CO2 fluxes as well as ecosystem characteristics have been measured at 5 sites in different ecological systems at Haibei (grassland), Yucheng (dryland), Taoyuan (paddy field), Qianyanzhou (forest land) and Fukang (saline desert) in China since the spring of 2002. These sites were set up initially for the validation of satellite data obtained from MODIS station established for the project "Asia-Pacific Environmental Innovation Strategy (APEIS)", which was launched in 2001 by the Ministry of the Environment of Japan, so we called them APEIS-FLUX system. The main objective of this study was to validate estimates of surface temperature, evaporation, soil moisture, as well as leaf area index and net primary productivity (NPP) generated by MODIS satellite data, and to understand the mechanisms controlling the exchanges of energy, water vapor and CO2 across a spectrum of time and space scales. The results show that both latent flux and CO2 flux are much higher in the crop field than those in the grassland and the saline desert, but the sensible heat flux is in the opposite way. Using the observed data to validate the MODIS data products, we found that different products have very different correspondence, which suggests that the algorithm to be used to process MODIS products needs to be revised by using the local dataset. We used the APEIS-FLUX data as the inputs and parameters of Biome-BGC model, and found that the revised model can simulate wheat growing process, heat and carbon fluxes over it well.

Key words: APEIS-FLUX, water vapor and CO2 flux, MODIS, terrestrial ecosystem model