Effect of land use/cover changes on aboveground biomass in and around Bidi-Bidi Refugee Settlement in Northern Uganda

Abstract

Uganda has seen a huge influx of refugees and asylum seekers in the past ten years mostly due to political instabilities in the neighbouring countries. Most of these refugees are settled in refugee settlements in traditionally rural and vegetated areas of Uganda. However, there have been reports of increased land use/cover changes of immeasurable proportions in these areas that have barely been quantified. Therefore, this study sought to quantify the effect of land use/cover changes on aboveground biomass in the Bidi-Bidi refugee settlement, Northern Uganda. High-resolution Sentinel-2 imagery for the study area for 2015, 2017 and 2020 was downloaded from the European Space Agency. Unsupervised classification and the CA-Markov model were used to determine the trend of land use/cover and predict the land use/cover changes respectively. Class and landscape-level metrics were used to assess the effect of land use/cover changes on landscape structural composition. The Production Efficiency Model (PEM) was used to determine the aboveground biomass for the study area and a One-way Analysis of Variance (ANOVA) was computed to establish the effect of changes in land use/cover on aboveground biomass. Results show that significant land use/cover changes have taken place in and around Bidi-Bidi refugee settlement. Built-up areas, refugee settlements, and subsistence farmlands increased by 0.3%, 12.2%, and 2.1% respectively whereas woodlands, wetlands, tree plantations, and grasslands decreased by 0.6%, 2.5%, 1.6% and 13.4% respectively. These patterns are projected to further intensify by 2040. The landscape in the area is increasingly becoming homogeneous as land use/cover changes intensify. The changes in land use/cover have reduced the aboveground biomass by 6.9%. The study concludes that settlement of refugees coupled with their unregulated activities has a significant effect on the land cover, and increased land use/cover changes cause fragmentation and homogeneity of the landscape thereby reducing landscape-level benefits. The study recommends the Office of the Prime Minister and other partners to consider incorporating buffer zones and green spaces in the spatial planning of refugee settlements in Uganda. Refugees and host communities should also be empowered to plant trees that grow rapidly to meet their energy needs and poles for construction.