Topography
Table 1: Proposed sustainability indicators
2.3 Remote Sensing and Land Use/Cover Changes
One essential component of sustainable development is information, which aids in planning, decision making and monitoring whether the activity is indeed sustainable (Skidmore et al. 1997). Timely and accurate change detection can provide the foundation to understand relationships and interactions between human and natural phenomena to better manage and use resources (Lu et al. 2004; Muttitanon and Tripathi 2005).
As a result of technological advancements, changes of the earth’s surface have become visible by satellite imagery. This has lead to remote sensing becoming the most effective tool for assessing and monitoring all these transitions (Deer 1995). Therefore satellite remote sensing has become a major data source for different change detection applications, because of the repetitive data acquisition capabilities, digital format suitability for computer processing and lower cost than those associated with traditional methods (Coppin et al. 2002; Deer 1995; Lu et al. 2004). In remote sensing, change detection and monitoring involves the use of multi-date images to evaluate differences and quantitatively analyse the temporal effects of the phenomenon between acquisition dates of images (Lu et al. 2004).
To implement digital change detection techniques, three major steps are involved (Lu et al. 2004). The first step is image pre-processing including geometrical rectification and image registration, radiometric atmospheric correction and topographic correction if the study area is in mountainous regions. The second step is the selection of suitable techniques to implement change detection analyses, while the last step is accuracy assessment. The reliability of the change detection process is strongly affected by various environmental characteristics and atmospheric effects (Jensen 1996; Lillesand et al. 2004). For the successful use of remote sensing for change detection, data used for monitoring should be acquired by the same sensor and be recorded using the same spatial resolution, viewing geometry, spectral band radiometric resolution and time of day (Lillesand et al. 2004; Lu et al. 2004).