Remote Sensing and Gis Based Urban Sprawl Susceptibility Analysis: A Case Study of Shashamane Town, West Arsi Zone; Ethiopia
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Date
2012-06
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Addis Ababa Universty
Abstract
In this paper, analysis was made on the urban sprawl susceptibility of the town of
Shashamanne using remote sensing and GIS techniques. To quantify and measure the urban
sprawl, an assessment was made on the extent and rate of land use/land cover (lulc) change
using multi-temporal landsat images during 1986, 2000 and 2011 and Shannon’s entropy
index. The supervised classification algorithm was employed to identify the major land
use/land cover types in the study area and they were categorized into 4 types: agricultural
lands, urban/built up areas, vegetated lands and bare fields. Being the focus was on the
spatial extent of built up areas; the LULC maps were further simplified into built up and
non-built up areas. With Shannon’s Entropy approach the degree of dispersion or
concentration of built up area’s development or sprawl was described. Finally, to predict
urban sprawl susceptibility of the study area the parameters such as land use/land cover
during 2011, slope, population density and distances from major road axis and rivers were
integrated using MCE function in ArcGIS. Results indicated that the study area has
undergone a tremendous change in urban growth and pattern during the study period.
Predominantly at the expense of agricultural lands and vegetated areas in the hinterlands,
built-up area was increased from 1977 ha (in 1986) to 2677 ha (in 2000) and further rose to
4329 ha (in 2011). Shashamanne town was expected to have sprawl pattern types of ether
linear/strip along highways, or expansion/cluster, or leapfrog as common to other urban
centers in the world. However, in reality, the town has rather had irregular sprawl pattern
type that is termed here as amoeboid shape. This is to mean that sprawl phenomenon in the
study areas was of a variable irregular pattern showing the combination of the three sprawl
patterns: linear/strip along highways, expansion/cluster and leapfrog. The analysis made
on urban sprawl susceptibility revealed that, of the total area of the study site 1023 ha (8%),
5279 ha (41%) and 394 ha (3%) were respectively, highly, moderately and marginally
susceptible to sprawling. This implies that large areas that are currently reserved as informal
green spaces, fertile farming lands and other natural resources have been threatened.
Keywords: Urban Sprawl susceptibility, GIS and Remote Sensing tools, LULC
Change, Urban Sprawl Measurement, Shashamanne Town.
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Keywords
Urban Sprawl susceptibility, GIS and Remote Sensing tools, LULC Change, Urban Sprawl Measurement, Shashamanne Town.