For the purpose of this study two specific forms of data were acquired and utilised in order to successfully carry out the research. The following section will be detailing the acquisition of the remotely sensed satellite imagery and the process behind acquiring the necessary key informant interviews from the Tongaat Hulett Company’s development sector. In addition, Figure 5B will summarise the complete methodological process conducted in this research.
5.4.1 Acquisition of the Satellite Imagery and related information
While some researchers prefer the use of aerial photographs with high resolution, the use of remotely sensed images is generally accepted for mapping and detecting changes in LULC (Crespi and De Vendictis, 2009;
Kuenzer et al., 2015; Xian, 2015). As a basic requirement for LULC change detection studies, remotely sensed imagery must be acquired from sensors with similar spectral, spatial, radiometric and temporal solutions (Crespi and De Vendictis, 2009; Powell and Roberts, 2010). Landsat 5 TM imagery were available from sources such as SANSA and also the USGS archives but due to the low spatial resolution of these images, the integrity, accuracy and overall results of the study would have been compromised.
For the purpose of this research, high resolution SPOT 5 imagery was obtained from the SANSA archives.
Launched on the 3rd of May 2002, the SPOT 5 satellite has three specific instruments; the high resolution geometric (HRG) sensor, the high resolution stereoscopic (HRS) sensor and a vegetation sensor (Lillesand et al., 2008; Lillesand et al., 2014). With the HRG and HRS sensors providing high spectral resolution and high resolution to the panchromatic imagery respectively, it was an ideal source of data for this particular study.
Looking back at the research objectives that were stipulated in the first chapter of this study, it was stated that this assignment was to identify the dominant land use and land cover changes that have occurred through time in Umhlanga Ridge with specific reference to the years 2006 and 2012. However, after further research and extensive communication with SANSA, it was decided that the images with the best clarity and least amount of cloud coverage was to be selected. With SPOT 5 images made readily available and easily accessible from SANSA’s archives, images from as early as 2006 (July) and as late as 2012 (April) were obtained. Ideally it would have been preferred to have attained images from a similar month in each of the mentioned years however; these images from those particular months provided the best visible detail and clarity of the study area.
5.4.2 Acquisition of Additional Data
For the purpose of this research endeavour, key informant interviews were conducted in order to attain information regarding the Tongaat Hulett Development sector’s involvement in the transformation of Umhlanga and the Umhlanga New Town Centre, as well as to identify the plans that the company has made for the future of Umhlanga’s urban landscape. Key informants are considered to be, “individuals who possess special knowledge, status or communication skills, who are willing to share their knowledge and skills with the researcher, and who have access to perspectives or observations denied the researcher through other means,” (Crabtree and Miller, 1999: 73).
Consequently, it became evident that in order to gain information regarding Umhlanga’s transformation, specific members of the Tongaat Hulett Development sector needed to be interviewed. However, when selecting a key informant it is important to note that they are not chosen by means of a random sampling method (Parsons, 2008). While random sampling assumes that each particular entity in a study is represented equally in the research; the selection of key informants is rather the opposite (non-random), with
the preferred choices being purposeful, strategic and based on an information rich sample (Crabtree and Miller, 1999).
As a result, Mr Andile Mnguni (Development Executive at the Tongaat Hulett Development sector) was selected as the first key informant for this study. From this point onward a snowball sampling method was employed in order to complete the research’s sample group. According to the theory supporting a snowball sampling, the method makes use of referrals to increase the overall sample size until the desired sample size is reached (Blanche et al., 2006; du Plooy-Cilliers et al., 2014; Kumar, 2014). Thereafter, Mr Mnguni suggested that Mr Rory Wilkinson (Urban Planning Director for the Tongaat Hulett Development sector) as an ideal candidate to participate in this study and consequently led to the selection of the participant, Ms Karen Petersen (Developments Director of the Tongaat Huletts Development sector) be included in the study as a key informant. Similarly, Ms Petersen identified, Mr David Jollands (Director of the Tongaat Hulett Development sector).
However, the most significant flaw that was experienced during this sampling processing was the lack of people being suggested to participate in the study by those who have already been interviewed. When questioned for an appropriate participant suggestion, Mr Jollands stated that the four already documented interviewees were the most suitable individuals as they were most actively involved in the initial and current transformation of Umhlanga. Although the original sample size was meant to be a maximum of ten participants, the four people who participated in this study were able to provide information for this research initiative. Furthermore, this remained in compliance with the snowball sampling method, which stated that the process of collecting the referrals into the sample group must continue, “until the required number or saturation point has been reached, in terms of the information being sought,” (Kumar, 2014: 208).