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The use of remote sensing to monitor land use change and assess its effect on the hydrology of Tuggeranong Creek catchmentDao, Minh Truong, n/a January 1993 (has links)
Since the launch of the first earth resources monitoring satellite, remote
sensing imagery has been used to provide information on the progress of
urbanization, and land cover and land use change. The launch of the first
SPOT satellite marked a significant improvement in spatial and spectral
resolution for discriminating individual targets and increased the potential to
acquire more information regarding land cover and land use.
This study aims to investigate the capability of using SPOT digital imagery for
monitoring land use change in the urbanised catchment of Tuggeranong Creek
in the Australia Capital Territory, and assess its effects on catchment
hydrology.
SPOT multispectral and panchromatic imagery was acquired over the study
area for January 1987 and September 1990. This imagery was digitally
processed and analysed using microBRIAN (MB) V3.01 software to derive
information on land cover and land use within the catchment. Multi-temporal
imagery was co-registered to a base map with sub-output pixel accuracy. In
order to improve spatial resolution, the multispectral imagery was merged with
panchromatic imagery acquired on the same day using HIS and HPF
techniques. The HPF technique retained more integrity of the original
multispectral data than did the HIS technique. Both HPF merged and unmerged
(original) image sets were used to assess the possibility of using higher
spatial resolution imagery in subsequent classification and change detection
analysis. On the basis of statistical calculation, non-vegetation classification
results were found to be consistent between merged and un-merged imagery,
but not consistent for vegetation classes. The inconsistency was found to be
the result of seasonal differences in phenology and sun angle. However more
small sub-pixel sized features such as houses and lawns were identified using
merged imagery. Regression differencing and post classification comparisons
were performed on both merged and unmerged image sets to detect temporal
changes which had occurred between both image dates. As expected, merged
imagery led to more sub-pixel sized examples of change being highlighted
using both the HPF and HIS techniques. However, errors associated with
multi-temporal image registration, compounded by classification errors arising
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from seasonal differences, meant that the reliability of all identified incidences
of change could not be validated. Nevertheless, post classification change
detection was found to be the most useful approach for identifying the nature
of change from one type of land use to another.
The results of classification and change detection techniques were used to
diagnose likely changes in catchment hydrology attributable to changes in land
use. Preliminary hydrologic analyses found that catchment yield is more
sensitive to changes in land use than runoff volume or peak flood discharge.
This study confirms that SPOT imagery can be used for mapping and
monitoring land use change in urban areas. SPOT imagery was found to be
suitable for providing information on land use and land cover changes and
assessing the likely hydrologic consequences of such change. The use of
imagery from anniversary dates would further improve the reliability of
hydrologic assessments based on remote sensing of land use change.
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