IDL-BNC @ IDRC >
IDRC / CRDI >
IDRC Research Results / Résultats de recherches du CRDI >

Please use this identifier to cite or link to this item: http://hdl.handle.net/10625/47422

Title: Evaluating the consistency of the 1982–1999 NDVI trends in the Iberian Peninsula across four time-series derived from the AVHRR Sensor : LTDR, GIMMS, FASIR, and PAL-II
Authors: Alcaraz-Segura, Domingo
Liras, Elisa
Tabik, Siham
Paruelo, José
Cabello, Javier
Keywords: SEASONAL MANN-KENDALL TREND TEST
TEMPORAL TRENDS ANALYSIS
SPATIAL STATISTICS
PARTIAL MANTEL TEST
CARBON GAINS
SPAIN
PORTUGAL
IBERIAN PENINSULA
Issue Date: 2010
Publisher: Molecular Diversity Preservation International, Basel, CH
Abstract: Successive efforts have processed the Advanced Very High Resolution Radiometer (AVHRR) sensor archive to produce Normalized Difference Vegetation Index (NDVI) datasets (i.e., PAL, FASIR, GIMMS, and LTDR) under different corrections and processing schemes. Since NDVI datasets are used to evaluate carbon gains, differences among them may affect nations’ carbon budgets in meeting international targets (such as the Kyoto Protocol). This study addresses the consistency across AVHRR NDVI datasets in the Iberian Peninsula (Spain and Portugal) by evaluating whether their 1982–1999 NDVI trends show similar spatial patterns. Significant trends were calculated with the seasonal Mann- Kendall trend test and their spatial consistency with partial Mantel tests. Over 23% of the Peninsula (N, E, and central mountain ranges) showed positive and significant NDVI trends across the four datasets and an additional 18% across three datasets. In 20% of Iberia (SW quadrant), the four datasets exhibited an absence of significant trends and an additional 22% across three datasets. Significant NDVI decreases were scarce (croplands in the Guadalquivir and Segura basins, La Mancha plains, and Valencia). Spatial consistency of significant trends across at least three datasets was observed in 83% of the Peninsula, but it decreased to 47% when comparing across the four datasets. FASIR, PAL, and LTDR were the most spatially similar datasets, while GIMMS was the most different. The different performance of each AVHRR dataset to detect significant NDVI trends (e.g., LTDR detected greater significant trends (both positive and negative) and in 32% more pixels than GIMMS) has great implications to evaluate carbon budgets. The lack of spatial consistency across NDVI datasets derived from the same AVHRR sensor archive, makes it advisable to evaluate carbon gains trends using several satellite datasets and, whether possible, independent/additional data sources to contrast.
URI: http://hdl.handle.net/10625/47422
ISSN: 1424-8220
Project Number: 104783
Project Title: Land Use, Biofuels and Rural Development in the La Plata Basin (Latin America)
Appears in Collections:2010-2019 / Années 2010-2019
IDRC Research Results / Résultats de recherches du CRDI
Research Results (CCW) / Résultats de recherches (CCE)
Latin America and the Caribbean / Amérique latine et Caraïbes
Water and Agriculture / Eau et agriculture

Files in This Item:

File Description SizeFormat
133763.pdf
3.95 MBAdobe PDF

Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.

 

Valid XHTML 1.0! DSpace Software Copyright © 2002-2010  Duraspace - Feedback