Mapping Mediterranean rangeland condition using MODIS NDVI time series


The aim of this study was to evaluate the potential of MODIS NDVI time series analysis for evaluating Mediterranean rangeland conditions. Field data were collected in the season 2006-2007 and 2007-2008 in 25 and 42 sites respectively. The analyzed sites were classified in three rangeland degradation classes, on the basis of expert knowledge. Quantitative indicators of rangeland condition were also measured in a subset of sites. We analyzed the relationship between MODIS NDVI time series and measured properties of rangeland vegetation, in order to assess which factor related to vegetation condition may have a major influence on the NDVI seasonal profile. The Local NPP Scaling (LNS) method was then applied and its potential for discriminating the degradation classes was evaluated. Finally, LNS maps were generated for the period 2000-2008 and analyzed to identify areas which exhibited persistently low LNS values. Results indicate that the LNS method applied on MODIS NDVI time series allows mapping Mediterranean rangeland conditions in central Sardinia and could represent an important tool for preventing land degradation phenomena.

Proceedings, 33rd International Symposium on Remote Sensing of Environment, ISRSE 2009, pp. 115-118