Estimating the Potential Evapotranspiration of Poyang Lake Basin Using Remote Sense Data and Shuttleworth-Wallace Model

摘要

The potential evapotranspiration (ET) is one of the key inputs to hydrological modeling. There are many evapotranspiration models that have been developed and validated but the efficiency is not high enough for poor estimation results or difficult data collection. While, the Shuttleworth-Wallace (S-W) model can consider two coupled sources in a resistance network and some researchers show that the S-W model can receive a good results. In addition, the S-W model is physically-based and all required data are publicly available and can be applied to data-poor or ungauged basins. As such, the S-W model was used to estimate the potential ET of Poyang lake basin for the period 1982 to 2001. The results show that the averaged ET fluctuate at 900 mm and appear an inflexion in 1992. The variation of averaged ET (also ET in particular land cover type) is inconspicuous in autumn and winter, while prominent in spring and summer. The ET is maximal in July and August and minimal in winter. The interannual distribution form is consistent with the temperature distribution. The spatial distribution of ET is largely uneven with larger values in south than in north and has a close relationship with the distribution of LAI.