Multi-site modeling of land surface-atmosphere exchanges at the extent of an agricultural Mediterranean region

Carlo Montes, NASA Goddard Institute for Space Studies, carlo.montes@nasa.gov (Presenter)
Jean Paul Lhomme, Institute of Research for Development, France, lhommejp@supagro.inra.fr
Frederic Jacob, Institute of Research for Development, France, frederic.jacob@ird.fr

The accurate monitoring of the water cycle at the watershed level requires the knowledge about the spatial and temporal dynamics of water and energy exchanges between the land surface and the atmosphere. This is particularly important for Mediterranean regions, where the evapotranspiration (ET) is the main output of the annual water balance and future projections show a systematic decrease in annual precipitation. Recent advances in terms of modeling, observations and remote sensing tools, allow considering both the local and the regional extent over complex surfaces such as row crops. This work proposes a modeling approach of soil-vegetation-atmosphere transfers (SVAT) that can be used at the extent of an agricultural region (watershed), combined with a parameter optimization procedure and optical/infrared remote sensing methods. A 1-D model with regional focus was developed to simulate the energy and water balance of a 3-source row crop (vineyard). The model was applied and validated using ground-based data obtained in southern France, and a multi-objective optimization method was used in order to perform a sensitivity analysis and model calibration. Secondly, Landsat and ASTER imagery was used in order to estimate watershed ET by using a contextual approach. Finally, satellite estimates of ET and soil moisture measurements were used jointly in order to calibrate the SVAT model and to obtain multi-site simulations of the water balance on a set of plots in the study area. Results are presented by comparing the performance of ASTER and Landsat to calibrate the model, showing that the model performance is highly dependent on data sources used for its calibration, but realistic simulations (time series) can be obtained by using satellite ET and measured soil water content after model calibration.

Presentation: 2015_Poster_Montes_233_150.pdf (7902k)

Presentation Type:  Poster

Session:  Theme 1: Tracking habitat change through new integrative approaches and products   (Mon 1:30 PM)

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Poster Location ID: 233