ABSTRACT Remote sensing is nowadays considered to be a valuable input for the annual collection o... more ABSTRACT Remote sensing is nowadays considered to be a valuable input for the annual collection of crop statistics. Derived crop maps can serve as a baseline for yield or area estimation or to target next year's census. For subsistence farming, where small parcels are mixed with other land use, crop mapping remains very challenging. This article evaluates the potential of discriminating crops in West Shewa, an area with small-scale farming in central Ethiopia. A hard classification of high-resolution (30 m) images, yielding good results for commercial farming, could not deal with mixed pixels due to the small parcels. Very high resolution (4 m) images have a more appropriate pixel size, although they only cover subsets of the region. The very high resolution classification was used to calibrate a neural network for sub-pixel classification of the high resolution images. The accuracies were not satisfactory, but did at least demonstrate the potential of this approach.
The Belgian Crop Growth Monitoring System (B-CGMS) uses the 1km²-resolution imagery of NOAA-AVHRR... more The Belgian Crop Growth Monitoring System (B-CGMS) uses the 1km²-resolution imagery of NOAA-AVHRR and SPOT-VEGETATION to improve its yield estimates. The pre-processed images are converted to fAPAR and combined with meteorological data (irradiance, temperature) to daily growth values by means of the Monteith approach. The regional means of the cumulative monthly growth numbers are calibrated against official harvest statistics by
ABSTRACT Remote sensing is nowadays considered to be a valuable input for the annual collection o... more ABSTRACT Remote sensing is nowadays considered to be a valuable input for the annual collection of crop statistics. Derived crop maps can serve as a baseline for yield or area estimation or to target next year's census. For subsistence farming, where small parcels are mixed with other land use, crop mapping remains very challenging. This article evaluates the potential of discriminating crops in West Shewa, an area with small-scale farming in central Ethiopia. A hard classification of high-resolution (30 m) images, yielding good results for commercial farming, could not deal with mixed pixels due to the small parcels. Very high resolution (4 m) images have a more appropriate pixel size, although they only cover subsets of the region. The very high resolution classification was used to calibrate a neural network for sub-pixel classification of the high resolution images. The accuracies were not satisfactory, but did at least demonstrate the potential of this approach.
ABSTRACT Although the importance of ENSO on hydrological anomalies has been recognized, variation... more ABSTRACT Although the importance of ENSO on hydrological anomalies has been recognized, variations in sediment fluxes caused by these extreme events are poorly documented. The effect of ENSO is not limited to changes in sediment mobilization. Since ENSO events can affect terrestrial ecosystems, they may have important effects on sediment production and transport in river basins over time spans that are longer than the duration of the event itself. The Catamayo-Chira basin is an interesting casestudy for investigating ...
ABSTRACT Remote sensing is nowadays considered to be a valuable input for the annual collection o... more ABSTRACT Remote sensing is nowadays considered to be a valuable input for the annual collection of crop statistics. Derived crop maps can serve as a baseline for yield or area estimation or to target next year's census. For subsistence farming, where small parcels are mixed with other land use, crop mapping remains very challenging. This article evaluates the potential of discriminating crops in West Shewa, an area with small-scale farming in central Ethiopia. A hard classification of high-resolution (30 m) images, yielding good results for commercial farming, could not deal with mixed pixels due to the small parcels. Very high resolution (4 m) images have a more appropriate pixel size, although they only cover subsets of the region. The very high resolution classification was used to calibrate a neural network for sub-pixel classification of the high resolution images. The accuracies were not satisfactory, but did at least demonstrate the potential of this approach.
The Belgian Crop Growth Monitoring System (B-CGMS) uses the 1km²-resolution imagery of NOAA-AVHRR... more The Belgian Crop Growth Monitoring System (B-CGMS) uses the 1km²-resolution imagery of NOAA-AVHRR and SPOT-VEGETATION to improve its yield estimates. The pre-processed images are converted to fAPAR and combined with meteorological data (irradiance, temperature) to daily growth values by means of the Monteith approach. The regional means of the cumulative monthly growth numbers are calibrated against official harvest statistics by
ABSTRACT Remote sensing is nowadays considered to be a valuable input for the annual collection o... more ABSTRACT Remote sensing is nowadays considered to be a valuable input for the annual collection of crop statistics. Derived crop maps can serve as a baseline for yield or area estimation or to target next year's census. For subsistence farming, where small parcels are mixed with other land use, crop mapping remains very challenging. This article evaluates the potential of discriminating crops in West Shewa, an area with small-scale farming in central Ethiopia. A hard classification of high-resolution (30 m) images, yielding good results for commercial farming, could not deal with mixed pixels due to the small parcels. Very high resolution (4 m) images have a more appropriate pixel size, although they only cover subsets of the region. The very high resolution classification was used to calibrate a neural network for sub-pixel classification of the high resolution images. The accuracies were not satisfactory, but did at least demonstrate the potential of this approach.
ABSTRACT Although the importance of ENSO on hydrological anomalies has been recognized, variation... more ABSTRACT Although the importance of ENSO on hydrological anomalies has been recognized, variations in sediment fluxes caused by these extreme events are poorly documented. The effect of ENSO is not limited to changes in sediment mobilization. Since ENSO events can affect terrestrial ecosystems, they may have important effects on sediment production and transport in river basins over time spans that are longer than the duration of the event itself. The Catamayo-Chira basin is an interesting casestudy for investigating ...
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Papers by Herman Eerens