Table 2. Number and size
of sites in the
Table 4. 1980 classification scheme.
detailed
Dudley area.
Addition;
1980 Dudley Derelict Land
ability
1971 Dudley Derelict
detectic
sites
hectare
%
mean
areas/ba:
hectares.
no. sites.
(1983) .
spoil heaps
11
13.2
2.9
1.2
Increc
0-0.5
2
excavations/pits
15
39.3
8.7
2.6
do not
0.51-1
18
military
0
0
0
0
provides
1.01-1.5
19
disused rail land
4
6.6
1.4
1.6
monitorii
1.51-2
14
disused sewage works 1
0.8
0.2
0.8
cover mu
2.01-3
17
disused waterways
3
5.6
1.2
3.1
state the
3.01-4
9
neglected land
85
260.6
57.6
3.1
cause cl<
4.01-5
6
other
2
3.9
0.9
2
from mat
5+
32
than res
ground truth
64
122.5
27.1
1.9
Baumann
total 117
accuracy.
total
185
425.2
100
and Forst
1980 Dudley Derelict
the prob
It is apparent
that the air survey
methods
urban la
hectares.
no. sites
0-0.5
0.51-1
1.01-1.
51-2
01-3
01-4
01-5
1,
-2,
3,
4 ,
5+
42
47
27
11
21
12
5
20
total 185
The number of sites in the 1-5 ha range
seems to have remained reasonably stable,
with a reduction of 11 sites over the period
being evident. However, with reference to
sites over 5 ha a significant reduction in
number has occurred from 32 to 20 sites.
Larger sites were generally of the neglected
waste land category, the type of land that is
relatively easy to reclaim. It appears that
much of the land has been returned to private
development and recreational use. The move
towards these uses seems reasonable
considering the Countryside Review Committee
(1976) statement concerning reclaimed land
that 'the original agricultural quality is
hardly ever recovered'.
Tables 3 and 4 reveal the classification
results for 1971 and 1980, these are complete
for the 1971 survey. The absence of 16 air
photographs means that 64 sites on the 1980
map have not been identified with regard to
type of dereliction, these are indicated as
'ground truth' in the classification and the
aerial data has been abstracted from the WMCC
1980 ground survey. The author is currently
performing categorization of these sites,
therefore, at the present time, it would be
fatuous to attempt any comparison between the
data sets and they are presented merely as a
guide.
Table 3. 1971 classification scheme.
19.7.1 D.udl£yL..-D.£xelict Land
sites hectare
spoil heaps
excavations/pits
military
disused rail land
disused sewage works
disused waterways
neglected land
other
11
14
0
6
0
4
82
0
29.4
137.4
0
14.7
0
8
382.1
0
5.
24
0
2,
0
1,
66,
0
outlined in this paper are efficient and
accurate, with the study results reflecting
county and district changes. It has been
demonstrated by Collins and Gibson (1980)
that aerial surveys have substantial
advantages over traditional ground based
surveys, which take up to 12 times as long,
cost 4.5-8.5 times as much and do not locate
as many sites.
Satellite monitoring in urban areas
total
117
571.6 100
The previous section has demonstrated the
accuracy and benefits of using aerial
photography in the assessment of specific
urban land covers. One of the main problems
with such surveys is that councils obtain
coverage on an aperiodic basis only. In
considering reclamation, Bullard (1983)
explains the philosophy behind this, 'The
cost of monitoring may be a small percentage
of the total cost of reclamation but like any
'service' they are only fully appreciated
when they can show significant changes taking
place in one or more of the conditions'. It
is unlikely that the mentality of local
authorities will be changed and therefore
another source of monitoring data needs to be
utilized. Satellite imagery is readily
available and being multitemporal is suited
to the needs of local authorities. The use
of such data is well documented for
agricultural and other land uses, however
interest is increasing in using high spatial
and spectral resolution systems, such as SPOT
1 and Landsat 5 TM in urban studies.
Necessarily there are problems with the new
data types and what follows is a brief
evaluation of their suitability for
qualitative and quantitative urban
monitoring.
Landsat MSS imagery has been used in the
urban environment, but only with limited
success. Wang (1984) notes that studies in
the urban environment concentrate on those
areas requiring less resolution, such as
boundary changes, and that few have realised
the harder task of identifying urban land use
categories.
The TM appears to have advantages over MSS
data in terms of data quality that may figure
significantly in urban area analysis. Anuta
(1984) reveals that using the same clustering
and merging sequences, TM data exhibits 42
classes as opposed to 21 from MSS.
Additional evidence of the increased
dimensionality in TM opposed to MSS is
recognised when Principal Component (PC)
images are examined. Quattrochi (1982 and
1985) has recognised that using PC images in
ratio and photographic forms facilitates
take the
pixel diJ
ref lect ii
surround
readings.
such cor
(1979) v
condition
as sharp]
land use'
Bounda
the urbai
infrequer
boundary
effects.
that up 1
scenes ar
that wit]
do not lc
being c:
int roduc
specific
effect, <
in a nei<
responsit
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discrimir
regions,
(PSF) . A
seriousl;
classes
Accordin
represen
deconvol
estimate,
' spatial
improper]
order ti
sampling
The views
of sense
improved
suggests
increasi
accuracy
variabil:
and b) a
24%) enh
diminish
should
classif ii
(1979) i:
Simulati
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decrease
increase'
nature ol
Final
higher r<
1. Reduce
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