Monitoring and assessment of urban green space loss and fragmentation using remote sensing data in the four cities of Malawi from 1986 to 2021
Kennedy Nazombe, Odala Nambazo
Abstract
Urban green spaces enhance cities' natural beauty, boost biodiversity, and promote the health and happiness of city residents, among other benefits. Despite the benefits of urban green spaces, their spatial configuration and composition are impacted by urban expansion. This study aims to investigate the spatial-temporal fragmentation trends of urban green spaces in four cities in Malawi (Blantyre, Zomba, Lilongwe, and Mzuzu). We, therefore, applied multi-temporal Landsat images to understand trends in urban green spaces from 1986 to 2021. Five landscape metrics, namely: percentage of land area (PLAND), number of patches (NP), patch density, largest patch index (LPI), landscape shape index (LSI), and mean patch size (MPS), were used to quantify the degree of urban green space fragmentation in Fragstats software. The results showed an increase in the NP, PD, and LSI and a decline in the LPI and MPA in the four cities. This is an indication of fragmentation and a reduction in green space. Rapid urbanisation has resulted in the loss and fragmentation of urban green space areas, which has been attributed to the rapid expansion of built-up areas at the expense of green spaces. The present study is the first to incorporate landscape metrics to understand the spatial heterogeneity of the composition and configuration of green spaces in all the cities of Malawi. The findings of this study contribute to an understanding of how urban growth impacts fragmentation and the loss of urban green spaces and offer valuable insights for better spatial planning and management of cities.