Land Use /Land Cover Dynamics in Prosopis Juliflora Invaded Area of Metehara and the Surrounding Districts Using Remote Sensing & GIS Techniques
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Date
2008-06
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Addis Ababa Universty
Abstract
Land use and land cover changes are derived by natural process and anthropogenic interference
in ecosystem. Appropriate management of natural resources requires quick and up-to-date
information for effective decision making. The aim of this study is to generate such kind of
information using RS and GIS technology to support the land use planning and strategy
formulation of the newly emerging problem of the study area. The present study has been
attempted to identify and quantify the main land use and land cover change that occurred for the
last three decades. Besides, in this study assessment of the spatial distribution of Prosospis
juliflora tree species using geostatistical analysis has been conducted. Three satellite imageries
of Landsat MSS 1973, Landsat TM 1986 and ASTER 2002 were utilized for detection of Land
use/land cover change. Prior to change detection analysis, land use/land cover map of 1973,
1986 and 2002 was generated. Eight land use/land cover classes have been identified from the
three independent image classification processes. Subsequently, post classification change
detection method was applied to quantify the land use/land cover change and to provide
information about the source and destination of the change. The change detection analysis
revealed the existence of significant land use/land cover change in the study area. The findings of
change detection analysis indicates the continuous spatial increment of cultivated land, bare land
and water body (Lake Beseka) at the expense of grass land and open shrub land. The rate of
expansion of Lake Beseka and cultivation land was 109.9 ha and 63.8 ha per year from 1973 to
2002, respectively. On the other hand, the rate of decrease in spatial extent of open shrub land
and grass land was 182.4 ha and 38.5 ha per year from 1973 to 2002, respectively. Using
geostatitical analysis it has been possible to map the current invasion of the nuisance plant
P.juliflora overcoming the problem of getting high spatial and spectral resolution satellite image.
From the geostatistical analysis, the highest and the lowest density of the species has been
observed at the southern and north western part of the study area, respectively. In addition, there
has been a trend in decrease of P.juliflora density from south to north western and north eastern
part of the study area. The infestation of P.juliflora has been observed in areas of relatively
better moisture and lower altitude of the study area. Furthermore, socio-economic survey was
conducted to assess the social and environmental impact of P.juliflora and the results of the
survey disclosed that 91% of the respondent said that the species has a negative impact on other
plants. In addition, 76% of the respondent from high infestation area and 90% from medium
infestation area believed that P.juliflora has been threatening the livestock production by
encroaching the grazing land. In general, significant land use/land cover change in the form of
conversion and modification has been occurred in Metehara and its surrounding area. The
outcome of land use/land cover change, geostatistical and socio-economic survey analysis can
serve local and regional planners as a primary source of information for better management of
natural resources in the study area.
Key words: RS & GIS, LULC Change, Conversion and Modification, Geostatistics, Invasion,
Prosopis juliflora
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Keywords
RS & GIS, LULC Change, Conversion and Modification, Geostatistics, Invasion, Prosopis juliflora