Geography Reference
In-Depth Information
Fig. 2 Screenshots of Google Earth embedded clickable hyperlinks describing a tabular data of
local climate change conditions and b graph illustration of monthly temperature and rainfall
variations
3.2 Development of Tabular and Graphical Data
To provide further contextual information and complement the time-series visu-
alisations described above, we developed a method to associate tabular and graph
data to the centroid of each raster dataset. The tabular and graph data display are
embedded within Google Earth, using the following workflow. This workflow is
applied to temperature and rainfall variables across multiple years at each specific
point.
The climate data rasters (provided in text (.asc) format) were, through suc-
cessive GIS processes (later automated through python geoprocessing scripts),
georeferenced, and converted to vector point data. The climatic data from each
vector file was then combined into a single file by merging their attribute table
values. The table data obtained for annual averages temperature and rainfall for the
1961-1990 historical average and the year 2070 were exported directly into a
KML file, thought the use of the Export to KML 2.5.4 ArcGIS extension (available
from
www.esri.com
) and formatted into a tabular structure through edition of the
'KMLFeature description' using HTML (see Fig.
2
a). Finally, a graph of the
monthly changes in maximum, minimum temperature and accumulated rainfall for
the year 1961-1990, 1998-2007, 2020 and 2050 were produced for each centroid
using the tabular data produced earlier in the process. Graphs were produced as.
PNG images via a Python script using the Numpy and Matplotlib libraries. These
graphs were then inserted into the KML through the use of the Export to KML
extension (see Fig.
2
b).
This method allowed the creation of KML files that contained the climate data
outputs associated with the centroid for each grid cell. This information is con-
tained
within
the
KML
'placemark'
(a
clickable
point
feature)
displaying
