An assessment of the impacts of land use changes on the Duthuni wetland stream using remote sensing, GIS and social surveying: a case study in Limpopo Province, South Africa

Abstract

This is a case study research that focuses on the assessment of the impacts of land use changes on the Duthuni wetland ecosystem in Limpopo Province using geospatial techniques and Social Survey. SPOT 4 satellite images which covered the time frame between 1999, 2005 to 2012, were used. The unit of analysis included different institutions such as the local municipality, farmers, the heads of the households and Chief of the Village. In this study, different methods of sampling were used in different context for selecting participants and for sample size determination. The different instruments for data collection included the questionnaires, interviews, focus group interviews and documents review. Socio-economic survey and review of documents were carried out to understand historical trends, collect ground truth and other secondary information required. Data collected from the survey were captured and analysed using the Statistical Package for Scientific Solutions (SPSS). For quantitative analysis, Chi-Square and cross tabulation were employed in SPSS. Analysis of satellite imagery was accomplished through integrated use of ERDAS Imagine (version 2015) and ArcGIS (version 10.1) software package. The themes were identified and analysed using the content analysis based on the main research topics. The results show that the land use/ cover changes have occurred at an unprecedented rate over the years 1999 to 2012. From the year 1999 to the year 2012, the total land use/ cover conversions equal to 299.984 ha of land. The trend and spatial extent of land use/ cover changes had undergone considerable changes over the years in the study period. The major contributing factors included population increase, expansion of agriculture and lack of space to settle. The residential area was found to be the major factor contributing to land use change over the years with an increase of (102.87ha.). People residing in Duthuni village especially along the wetland ecosystem consist of the majority of female-headed households. There is no proper facilitation and mentoring in the village by the government in order to resolve social problems when it comes to land use change. Water pollution and soil erosion were found to be the major concern by wetland users such as farmers and residents. Lack of knowledge has also been identified as one of the driving factors of environmental impacts of land use change in the area. Food was the most resources with 41% which the community gets from the wetland.