International Archives of the Photogrammetry, Remote Sensin g and Spatial Information Sciences, Vol XXXV, Part B2. Istanbul 2004
Figure 1. Study area:
(Trabzon Province with its administration sections)
2.2 Soil Data
In Turkey, The General Directorate of Rural Services
realizing its activities under the Ministry of Agriculture and
Rural Affairs is responsible for production of soil related
information. Produced by this institution, maps scaled
1/100.000 were digitized. Land use types (LUT) are 8 classes
on this map. Respect to soil damage and restrictions, these
classes are range from 1. to VIII. Besides, agricultural lands
are divided into 4 classes. Having I. degree importance,
agricultural lands are named as absolute agricultural classes.
These agricultural classes involve I. and II. degree classes
and the other classes lands having needed irrigation except
forest lands and moorlands. Having II. degree importance
agricultural lands involve III. class land use capability lands.
Having IIl. degree importance agricultural lands involve
vineyards-gardens and special product lands which are in
other than L., I. and IIL. class lands. IV. class lands are named
as the other lands. These classes involve the lands except T.,
IT. and III. agricultural lands (Balci, 1996).
2.3 Relief Data
Digital Elevation Model (DEM) was digitized from
1/100.000 scaled Standard Topographic Maps. Contours on
these maps are drawn with a 50m elevation differences. DEM
of the study area was created by using ArcView 3.2 and
ArcGIS 8.2 GIS software’s. Slope Map (classified in
percentage) and Elevation Figures were generated by using
this DEM. Pixel dimensions of this Slope Map are 25x25m.
When considered in view of slope, three fourth of the total
arca of Trabzon province consist of areas with a slope rate of
above 30%. Besides, areas with a slope rate of 50% or above
constitute 40% of the total area of the province (Reis, 2003).
2.4 Remote Sensing Imagery and Land Cover
In the Eastern Black Sea Region of Turkey, the principle
challenges in generating land cover types are rough
topographic structure, rich in turns of plant species and
scattered agricultural lands. Therefore, some difficulties were
encountered in processing remotely sensed data in the region.
In this study, a single date image of Landsat ETM+ (Path
173; Row: 32) on October 19, 2000 were used to generate
376
land cover types. Using the image, after extracting an
application area of approximately 120x90 km covering
administrative boundaries of Trabzon province, some other
required further studies were implemented on this area.
Landsat ETM+ image has 6 multi-spectral bands with 30m
resolution, 2 thermal bands with 60m resolution and a
panchromatic band with 15m resolution.
For the study, a total of ten land cover classes arc chosen.
These are pasture, water, deciduous, coniferous, mix wood,
green tea, hazelnut, rocky, settlement and agriculture.
Training area data for these classes were obtained using
mobile GPS in two different seasons (for May&September).
Supervised classification process was realized. During the
classification process each of the following algorithms were
tested: Minimum Distance, Mahalanobis Distance and
Maximum Likelihood with several thresholds. It was seen
that the Standard Maximum Likelihood Method provides the
best result with multi-spectral bands (123457) when the
supervised approach is used. Afterwards, to analyze this
classification, the overall accuracy percentage, user’s and
producer’s accuracy and the Kappa Coefficient that provide
the statistical evaluation of these accuracy values were
calculated. The overall accuracy of this classification was
84.68% and the Kappa Coefficient was 0.829. The hazelnuts
producer's and the user's accuracy were realized respectively
87.9 94 and 83.5 94.
3. DETERMINATION OF THE POTENTIAL
HAZELNUT AREAS
Turkey state was brought into force a law numbered 2844 in
1983, named as “The act about planning of the hazelnut
production and determining of the planting areas”, for
gaining thc most yield from the hazelnut plants and balancing
the world markets harvest of the hazelnuts. The last
regulation was done in January 2002 for constricting the
hazelnut areas and enhancing the hazelnut productivity.
According to this regulation the harvesting of hazelnut can be
done the areas as follows;
a) in the areas of which maximum elevation is up to 750 m.
b) in Ill.class agricultural areas and slope is more than 6%.
c) in IVth or upper class of the land use ability areas
(Turkey official gazette, 2002).
Because of the resolution of land use map, obtained from
satellite image, is 28m the analysis of Potential Hazelnut
Areas (PHA) is done in grid format of which pixel dimension
is 28m. In this analysis procedures all data coverage are
transformed into a pixel dimension in 28m. The criterions
given above are used to determine the PHA in GIS context.
The spatial analysis module in ArcView for carrying out this
aim was used (Esri, 1996). According to this analysis, it is
assigned that there is total 101.384 ha PHA in Trabzon
province which is 21.896 of entire the province.
4. DISCUSSION
In Trabzon, there is an area of 164.370 hectares between the
elevations of 0-750 m, which is used as a criterion in
determining the general PHA. While 101.384 hectares of this
area is assigned as PHA, it is determined without taking into
consideration of the existing land cover. When the current
land cover is considered so as to determine the PHA, it will
be seen that the PHA will become less than the calculated
one obtained from Landsat ETM+ satellite image. According
to the results of analyses with land cover map, as given on
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