| Volumes and Issues Contents of Issue 2 Special Issue |
www.hydrol-earth-syst-sci-discuss.net/6/2301/2009/
doi:10.5194/hessd-6-2301-2009
© Author(s) 2009. This work is distributed
under the Creative Commons Attribution 3.0 License.
Regional estimation of daily to annual evapotranspiration with MODIS data in the Yellow River Delta wetland
1Alterra Green World Research, Wageningen University and Research Centre, The Netherlands
2National Marine Data & Information Service, Tianjin, China
3State key Laboratory of Remote Sensing Science, School of Geography, Beijing Normal University, Beijing, China
4Institute of Geographical Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing, China
5China National Climate Centre, Beijing, China
Abstract. Evapotranspiration (ET) from the wetland of the Yellow River Delta is one of the important components in the water cycle, which represents the water consumption by the plants and evaporation from the water and the non-vegetated surfaces. Reliable estimates of the total evapotranspiration from the wetland is useful information both for understanding the hydrological process and for water management to protect this natural environment. Due to the heterogeneity of the vegetation types and canopy density and of soil water content over the wetland (specifically over the natural reserve areas), it is difficult to estimate the regional evapotranspiration extrapolating measurements or calculations usually done locally for a specific land cover type. Remote sensing can provide observations of land surface conditions with high spatial and temporal resolution and coverage. In this study, a model based on the Energy Balance method was used to calculate daily ET using instantaneous observations of land surface reflectance and temperature from MODIS when the data were available on clouds-free days. A time series analysis algorithm is then applied to generate a time series of daily ET over a year period by filling the gaps in the observation series due to clouds. A detailed vegetation classification map is used to help identifying areas of various wetland vegetation types in the YRD wetland. Such information is also used to improve the parameterizations in the energy balance model to improve the accuracy of ET estimates.
This study shows that spatial variation of ET is significant over the same vegetation class at a given time and over different vegetation types in different seasons in the YRD wetland.
Discussion Paper (PDF, 4047 KB) Interactive Discussion (Closed, 6 Comments) Final Revised Paper (HESS)
Citation: Jia, L., Xi, G., Liu, S., Huang, C., Yan, Y., and Liu, G.: Regional estimation of daily to annual evapotranspiration with MODIS data in the Yellow River Delta wetland, Hydrol. Earth Syst. Sci. Discuss., 6, 2301-2335, doi:10.5194/hessd-6-2301-2009, 2009. Bibtex EndNote Reference Manager XML
