Geoscience Reference
In-Depth Information
7.3.2 Maps
Utilisation of maps from cadastral mapping for evaluation of long-term landscape
changes from 1826 to 1843, runs into the fact that mapping was done at a detailed
scale of 1:2.880 for 13.000 cadastral units. The total number of map sheets reaches
about 35.000, and it is obvious that their use in research is therefore somewhat
complicated in any effort to analyze a larger area. The set of map sheets has now
been digitised, and represents an exceptional database for evaluating landscape
changes. The basic procedure which was used in different sample areas is based
on: (1) Comparison with maps of different time horizons in GIS. (2) Evaluation
of range changes of individual categories and their layout in a cadastre unit. (3)
Evaluation of stable and instable areas, and finally (4) on total intensity of changes
(index of change, coefficient of ecological stability, coefficient of anthropogenic
effect and the like (for example Bicík, 1997; Bicík et al., 1996 and others). The pro-
cedure is quite demanding. It requires content and statistical unification of database
information, and obviously the generalisation of outputs is rather difficult. Without
any doubt, this procedure can serve as an interesting base for putting into prac-
tise detailed evaluation of landscape changes for specific purposes (complex land
reform, marking out local and regional territorial systems of ecological stability
(
ÚSES
) and the like). The procedure is more for application than for research. Only
the evaluation of several tens of sample areas, made of approximately five to ten
cadastral units in different positional, natural, and functional conditions could be a
path for scientific research. Creation of an adequate generalised map, for instance
in scale 1:250.000 for entire Bohemia is methodically extremely difficult due to the
necessary generalisation.
7.3.3 Remote Sensing Data as a Comparison Dataset
The importance of the remote sensing method has been confirmed by its own rapid
development (Lillesand & Kiefer, 2002; Walsh, Evans, & Turner, 2004). The remote
sensing data is, however, limited to the period from the middle of the Twentieth
century until today; the mass research use of photography in the process of mapping
the landscape did not develop until after the end of World War II. A very important
source of information for observing the state of the landscape from 1945 is historical
aerial survey photographs (Paine & Kiser, 2003). Three sets of aerial photographs of
the study areas from 1948 have been obtained. Contemporary land use of the study
areas is accurately documented by digital orthophotomaps that have their origin in
the ORTO CR project with the pixel size of 50 cm for the target scale of 1:5.000;
these data date back to 2004. The bases for the colour orthophotomap were aerial
survey photographs. They were digitised and provided in the uncompressed TIFF
format; georeference is in TFW format in the S-JTSK coordinate system (Unified
Cadastral Trigonometric Network).
The input data had to be adjusted to correspond to tasks, objectives and specific
features of landscape ecological investigations. Aerial photographs were digitised
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