Suchergebnisse

Deforestation contributes to carbon emissions and therefore to climate change. Within food systems, agricultural production is the stage which plays the largest role in deforestation and forest degradation, and it is therefore the focus of this chapter. There is a critical link between food systems and deforestation. Arable lands most often have a forested past. It might be ancestral, with deforestation having happened in the early occupation of land by humans or be very recent on current forest frontiers. Over the past two decades, commercial agriculture has overtaken subsistence agriculture as the main driver of deforestation in LI and LMI countries, especially in tropical areas.

Monitoring vegetation cover during winter is a major environmental and scientific issue in agricultural areas. From an environmental viewpoint, the presence and type of vegetation cover in winter influences the transport of pollutants to water resources. From a methodological viewpoint, characterizing spatio-temporal dynamics of land cover and land use at the field scale is challenging due to the diversity of farming strategies and practices in winter. The objective of this study was to evaluate the respective advantages of Sentinel optical and SAR time-series to identify land use in winter. To this end, Sentinel-1 and -2 time-series were classified using Support Vector Machine and Random Forest algorithms in a 130 km² agricultural area. From the classification, the Sentinel-2 time-series identified winter land use more accurately (overall accuracy (OA) = 75%, Kappa index = 0.70) than that of Sentinel-1 (OA = 70%, Kappa = 0.66) but a combination of the Sentinel-1 and -2 time-series was the most accurate (OA = 81%, Kappa = 0.77). Our study outlines the effectiveness of Sentinel-1 and -2 for identify land use in winter, which can help to change agricultural practices.