Remote Sensing Results

The Ha Tien Plain, located in the north-western part of the Mekong Delta, was once considered to be the last remaining extensive wetland area of seasonally inundated grassland in the Mekong Delta, supporting a high diversity in flora and a rich avifauna. Since the mid-1990s this valuable wetland ecosystem is threatened by the conversion into agriculture, aquaculture and forest plantations.

Different functions have been developed that perform different types of raster statistical analysis. In particular these functions generate histograms of pixels of a input image file that intersect either vector geometries or raster masks. The processes have been established as Web processing Services (WPS).

These tools are meant to support change detection analysis for e.g. landcover classifications from remote sensing data. They are based on the comparison of a pair of discrete raster images as e.g. coded landcover classifications from different years. They provide statistical and map information allowing the quantitative, qualitative and spatial evaluation and interpretation of changes that occured between the two input dates.

For the monitoring of water constituents in the site of investigation "Can Tho" two kinds of satellite data were used. Figure 1 shows SPOT4 satellite data (Spotimage, 2008-03-12, 03:15:57) and a map showing Total Suspended Matter (TSM) -corresponding "Turbidity"- based on the SPOT4 image. Turbidity [NTU] correlates to Particule Matter PM [mg/l]. The legend on the right side of the map describes the scaling of NTU. Start with light blue color for low Total Suspended Matter values going up to 60 NTU colored in pink.

The title of this map (Fig. 1) is “Land Use Classification 2007, Tam Nong testsite”. Besides the pixel-based approaches one of which the automated processor is still focussing on there are object-oriented classification approaches which are known to achieve very good results for classifying very high resolution data because of detail of information contained in the image.

The title of this map is “Vietnam – Mekong Delta –Population density, 2004”.

It depicts the distribution of population in the Mekong Delta. The legend on the right side of the map describes important map attributes, such as the class names, scaling factor, two quicklook images of the data source and additional map information. As the data source of this map, LandScan 2004 Global Population database of the Oak Ridge National Laboratory, was employed.

The title of this map is “Vietnam – Mekong Delta – Land Cover Classification II, 2001”.

The title of this map is “Vietnam – Mekong Delta – Plain of reeds – Seasonal inundation”.