An Analysis of Urban Land Use/Land Cover Changes in Blantyre City, Southern Malawi (1994–2018)

Abstract

Rapid and unplanned urban growth has adverse environmental and social consequences. This is prominent in sub-Saharan Africa where the urbanisation rate is high and characterised by the proliferation of informal settlements. It is, therefore, crucial that urban land use/land cover (LULC) changes be investigated in order to enhance effective planning and sustainable growth. In this paper, the spatial and temporal LULC changes in Blantyre city were studied using the integration of remotely sensed Landsat imageries of 1994, 2007 and 2018, and a geographic information system (GIS). The supervised classification method using the support vector machine algorithm was applied to generate the LULC maps. The study also analysed the transition matrices derived from the classified map to identify prominent processes of changes for planning prioritisation. The results showed that the built-up class, which included urban structures such as residential, industrial, commercial and public installations, increased in the 24-year study period. On the contrary, bare land, which included vacant lands, open spaces with little or no vegetation, hilly clear-cut areas and other fallow land, declined over the study period. This was also the case with the vegetation class (i.e., forests, parks, permanent tree-covered areas and shrubs). The post-classification results revealed that the LULC changes during the second period (2007)(2008)(2009)(2010)(2011)(2012)(2013)(2014)(2015)(2016)(2017)(2018) were faster compared to the first period (1994)(1995)(1996)(1997)(1998)(1999)(2000)(2001)(2002)(2003)(2004)(2005)(2006)(2007). Furthermore, the results revealed that the increase in built-up areas systematically targeted the bare land and avoided the vegetated areas, and that the vegetated areas were systematically cleared to bare land during the study period . The findings of this study have revealed the pressure of human activities on the land and natural environment in Blantyre and provided the basis for sustainable urban planning and development in Blantyre city.

Spatial-Temporal Land Use and Land Cover Changes in Urban Areas Using Remote Sensing Images and GIS Analysis: The Case Study of Opole, Poland

“…Each pixel was categorised into one of the four developed LULC classes: built-up area (residential, commercial, and service; industrial and transport; as well as recreational urban areas); vegetated areas (arable land, meadows, pastures, areas covered with low vegetation, allotment gardens, fallow land, and bare soil); wooded areas (forests, parks, wooded and semi-natural areas); and surface water areas (rivers, canals, reservoirs). The assessment of classification accuracy was also performed to quantitatively determine how effectively the pixels are grouped into the correct feature classes [78]. For this purpose, the test fields were distributed evenly outside the areas of the training fields, supported by information from the analysis of accurate maps (e.g., multi-temporal aerial photography, orthophotomaps).…”

“…On the basis of confusion matrix, it was possible to analyse parameters describing classification accuracy, such as overall accuracy, which is defined as accuracy between the classified map and the reference data as well as Kappa coefficient defining total classification error and the degree of conformity between the compared images. Kappa coefficient greater than 0.80 indicates excellent agreement; a value between 0.4-0.80 indicates moderate agreement, and a value less than 0.4 indicates poor agreement between classification categories [78]. Such analyses resulted in raster maps of LULC classification; also, magnitude of changes for the individual land cover class in each period were calculated.…”

Seismic fragility models for typical non-engineered URM residential buildings in Malawi

“…This trend will inevitably result in increased exposure to natural disasters, such as earthquakes and floods [2][3][4]. Additionally, owing to the unregulated and inadequately planned nature of urban growth in Malawi, informal settlements, typical of rural areas, will be expanded at the outskirts of major cities, such as Lilongwe and Blantyre [5]. Residential buildings are characterised by poor engineering and construction quality, and are therefore highly vulnerable to natural hazards [6].…”

Measuring the Smart Growth Spatial Performance in Developing City of Northwest China Plains Area

“…It is actually a process of inputting various resources into the regional urban-rural spatial system to acquire all kinds of outputs, which is input and output efficiency relationship. To quantify the efficiency relationship needs to construct input index system and output index system, where urban-rural integration is a firstlevel input index, and there are three second-level output indexes-efficiency outputs of urban-rural ecological integration, economic integration, and social integration as discussed by Mawenda et al [5].…”

“…However, only Sun Town was able to properly develop, while the overall spatial structure of the county remains sluggish. The urban town system is triangle-shaped and includes only a small number of key towns, playing a limited role in driving development to other towns as discussed by Mawenda et al[5]. Evolution of Dynamic Construction Land.…”