Spatio-temporal analysis of urban growth and its impacts on Rwampara wetland in the City of Kigali Rwanda

Abstract

This study aimed at analyzing the spatio-temporal patterns of urban growth and its impacts on Rwampara wetland located in Nyarugenge and Kicukiro districts of Kigali City. To achieve the above stated aim, the study used the existing literature related to spatio-temporal analysis for a good conceptualization of the study. In addition, the study centered on application of remote sensing technology, where four (4) Landsat images (1987; 1999; 2009; and 2018) were classified using supervised classification approach, with maximum likelihood technique, and served the analysis of Land Use and Land Cover (LULC) changes in Rwampara wetland. Moreover, the study used existing LULC data of 1990, 2000, 2010 and 2018 retrieved using remote sensing techniques, to investigate the overall changes in LULC in Kigali City. Finally, a consultative approach (especially interviews) was applied, where fifteen (15) decision makers and thirty (30) natives from Rwampara wetland neighborhoods were consulted. The study findings revealed that over the past four decades, urban growth in Kigali City has rapidly increased, while Rwampara wetland resources were degraded and declined over time. In this regard, there has been an increase of about 77% of built-up area over the last 31 years (1987 - 2018). This has led to the degradation of wetland resources, where Rwampara wetland has decreased from 24 ha in 1987 to only 7.7 ha in 2018. The total area of 16.3 ha has been lost to other land uses/cover types. In addition, other non-built-up cover has known a great loss of 112.7 ha during that period of time. It was also revealed that demographic factor (high population growth rate and high population densities) was the main driver of urban growth and wetland resources degradation in the study area. To curb the wetlands degradation and promote their wise use, the study suggested strict measures in terms of policies and regulations. In addition, the promotion of wetland resources ownership among local population could be another sustainable solution. Finally, a participatory approach could ensure effective and sustainable implementation of the existing policies. Key Words: Spatio-Temporal Analysis; Urban Growth; Wetland Degradation; Rwampara Wetland