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DETECTING AND QUANTIFYING LAND COVER AND LAND USE CHANGE
IN EASTERN MAU BY REMOTE SENSING
Kundu P.M', China S.S, Chemelil M.C and Onyando J.O
Department of Agricultural Engineering, Egerton University, Box 536 Njoro, Kenya
Abstract
Eastern Mau is an important water catchment area for lake Nakuru drainage basin. It has great potential for agricultural
development as manifested by the high yields of wheat, barley and dairy products from the few remaining large scale
farms. This area was once covered by rich vegetation of hi ghland evergreen forests which extended from the Mau hills
and turned into woodland dominated by acacia trees in the Rongai-Njoro plains. Remote sensing techniques and ground
survey methods were used to evaluate the land cover /land use change that occurred in the area over a period of about
40 years since 1964. A significant change of land use from forest to agriculture was evident from the interpreted results
of the photos taken in 1964 and 1969, the SPOT image of 1987, the Landsat image of 1989 and the ground survey of
2003. Deforestation, land fragmentation, cultivation of wetlands and rapid increase in human settlements have had
negative impacts on water resources resulting in reduced stream flows and ground water. Land use has changed from
planted forests and large scale farms of wheat, barley, and dairy to homesteads, kitchen gardens and small farms of
maize, beans, potatoes and vegetables with some people keeping one or two dairy animals. Currently, studies show
increasing land degradation in the area. Sheet and rill erosion is observed when it rains and gullies are beginning to
develop along some of the farm tracks. To contain the situation. satellite remote sensing was used to monitor and
provide data that can be used to evaluate and manage land use and land use change for sustainable development in Mau
East.
Keywords: Remote Sensing, Air photo-interpretation, Landsat, SPOT, Catchment
Introduction Methodology
Eastern Mau is in the Rift Valley Province of Kenya A systematic sequence of API was done on air
and lies between Rongai-Njoro plains and the upper photographs of 1969 to ensure that definite, reliable
slopes of the Mau hills. It is mainly covered by the and significant information was extracted. The central
Quaternary and the Tertiary volcanic deposits. The photograph was analysed using mirror stereoscopes. A
area is drained mainly by rivers Njoro and Lamriak full scene SPOT image (fig.5) covering Lake Nakuru
which originate from Eastern Mau escarpment and and Lake Naivasha drainage basins was manually
empty into Lake Nakuru and rivers kaumara, Nessuit interpreted and analysed. The general character as well
and Rongai which drain northwards to lake Baringo as details of the geology, drainage, plant cover and
and Bogoria. land use were drawn from surrogate indicators and
interpretation elements in the images. Vegetation
Remotely sensed data and ground survey methods cover was determined by the colour tone, the
were used to evaluate the land cover /land use change distribution, form and texture of plant-covered areas.
in the area for a period of about 40 years. A Land cover change was determined by comparing
combination of fine, medium and coarse resolution multi-temporal images. A subscene Landsat image of
images from different platforms were used to detect 1989 (fig.8) covering the recharge areas and the
changes. The study showed a significant change of mature sections of the rivers originating from Mau
land use from forest and woodlands to agriculture, and hills were interpreted. The large area covered in one
rural built-up lands. This was evident from the image was important for various kinds of regional
analysed results for the air photos of 1969, the SPOT studies with details of size 30-80 m being observed.
image of 1987, the Landsat images of 1984 and 1989 TM bands 4, 5, 3 were selected as they showed
and the ground survey of 2003 which gave a vegetation and land use features more clearly.
chronological landscape record. Deforestation, land
fragmentation, cultivation of wetlands and rapid Ground survey was carried out in the selected sample
increase in human settlements have had negative sites in 2003. In order to achieve unbiased samples,
impacts on water sources resulting in reduced stream surveys were based on an unaligned systematic
flows. Land use has changed from planted forests, random sample of fixed-size segments of | km x 1 km.
large farms of wheat, barley, and dairy to homesteads, Individual land parcels and ground cover classes were
kitchen gardens and small farms of maize, beans, identified in each sample segment. By the method of
potatoes and vegetables with one or two dairy animals. direct expansion, the area for each cover class was
determined for the entire study area. A high
densification of sample sites was preferred in order to
validate the consistency of land use cover database.
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