International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, Vol XXXV, Part B7. Istanbul 2004
In order to classify the heterogeneous land use in
eastern Mau, a simplified method known as EU-
LUCAES based on Anderson 1977 was applied. Field
survey provided the locations of known land use cover
types such as wheat farms and improved pasture
fields. It provided the locations of unknown features
such as rural built-up lands, heterogeneous crop and
subsistence farms which cannot be identified on the
Area by direct expansion
Mean proportion:
> n
y. = 1/n> y, (1)
i=l
Where,
). = Mean proportion of each coverage area
y; — Coverage proportion for each segment
n = number of segments in the sample
Total area under coverages
/ = ? 2
Z, * Dy, (2)
Where,
Z. = Estimate of the coverages area
D = Total study area
Variances of area estimator
Var(y.) =(1-n/N)1/(n(n- )Y 6; > pu (3)
i=l]
Var(Z,) » D'Var(y,) (4)
Where,
N= Total number of segments in the study area
Results and Discussion
The land cover classes identified in the area were as
shown in table 1.
406
image using visual interpretation techniques. It helped
identify the main physical environments of the study
area such as hills, valleys and rolling land. Data
verification process involved rechecking photographs
and images to determine if the interpretation was
correct, and where questions existed, the site was field
verified. At least a third of the segments were field
checked, results tabulated and compared to the
original interpretation.
Table 1: Land cover classes
Category Air Landsat Ground
Photograph | Image Survey
(1969) (1989) (2003)
Natural y y 0
forest
Planted y y 0
forest
Plantation X X y
eucalyptus |
Cultivated | y y y
land
Wooded y y y
grassland
Grassland y y y
Built-up y y y
land
Riverine y y y
vegetation,
fence
lines/belts,
y = positively identified x= not identified 0 = nil
Visual Image Interpretation
Air Photograph (1969)
The photograph was enlarged to show the land use
cover clearly. The fields on Tatton farm at Egerton
college as it was known then can be clearly seen in
figure 6. Other large scale farms shown are Finerose
(present Ndichu and Kiringu farms) and Growtch
(present Ngondu farm). Planted forest of coniferous
occupied the western part of the area.
Woodland/wooded grassland was found on the
southern and eastern parts of the area under study.
Arable agriculture and animal keeping was at the
middle and northern part. Woodlots and tree fence
belts/lines were common on farmland.
Landsat MSS (Jan. 1973)
The locational information provided in figure 4 shows
the main land cover types in this part of the Rift
valley. The Mau range, the Bahati escarpment and the
Aberdare range are covered in bright red which is
solar infra-red radiation by healthy chlorophyll-rich
vegetation. Although January is a dry period, the
richness of the red indicates the vigour of the leafs and
their sizes. Dark red represents broad leaved trees Or
woody shrubs seen on hillsides as seen on Menengai
crater and as strings of dark red lining stream
channels, fault lines and hillside gully valleys in many
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