Manuela Grippa

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Rain Use Efficiency (RUE), defined as Aboveground Net Primary Production (ANPP) divided by rainfall, is increasingly used to diagnose land degradation. Yet, the outcome of RUE monitoring has been much debated since opposite results were found about land degradation in the Sahel region. The debate is fueled by methodological issues, especially when using(More)
7 [1] We analyse the evolution of the fraction of water 8 surface (FWS), derived by SSM/I between 1988 and 2002 9 over the Western Siberia Lowland. This whole region 10 exhibits an increase in the amount of FWS that is in 11 agreement with the observed trends of the Ob river 12 discharge and precipitation. However, a similar increasing 13 trend is not found(More)
To document trends in land use and herbaceous production, 71 field sites sampled among cropped fields, fallow fields and rangelands in the Fakara region (Niger) were monitored from 1994 to 2006. The overall trend in land use confirmed the historical increase of the cropped areas since mid 20th century, at an annual rate of 2% from 1994 to 2006. This trend(More)
In the Sudano-Sahelian areas of Africa droughts can have serious impacts on natural resources, and therefore land surface moisture is an important factor. Insufficient conventional sites for monitoring land surface moisture make the use of Earth Observation data for this purpose a key issue. In this study we explored the potential of using reflectance data(More)
[1] This paper analyses the role of the El Niño–Southern Oscillation (ENSO) on the interannual variability of the leaf appearance dates of boreal forests in the Northern Hemisphere (1982–2004). We find significant negative correlations between the ENSO, quantified by means of the Southern Oscillation Index (SOI), and the leaf appearance dates in central(More)
In the SIBERIA-II project Earth Observation (EO) data are used to derive a set of products, which are then fed into global and regional greenhouse gas accounting approaches. The overall aim of the project is to devise an integrated “EO-modelling” methodology for full carbon accounting at regional scale, and to quantify the accounting for an over 3 Mio km(More)
using ENVISAT radar altimetry 2 3 C. Fatras, F. Frappart*, E. Mougin, M. Grippa, P. Hiernaux 4 5 Université de Toulouse, OMP, GET (UMR 5563 CNRS-UPS-IRD) 6 14 avenue Edouard Belin 31400 Toulouse – France 7 8 9 *Corresponding author: Géosciences Environnement Toulouse (GET) 10 Observatoire Midi-Pyrénées 11 14 avenue Edouard Belin 31400 Toulouse, France 12(More)