How Climate Change and Land Use/Land Cover Change Affect Domestic Water Vulnerability in Yangambi Watersheds (D. R. Congo)

David Ushindi Chishugi,Destin Itunda,Fiyo Losembe Félix,Josué Bahati Chishugi,Denis Jean Sonwa,Muhindo Sahani,Jean-Marie Kahindo

doi:10.3390/land10020165

Abstract

In the tropics, the domestic water supply depends principally on ecosystem services, including the regulation and purification of water by humid, dense tropical forests. The Yangambi Biosphere Reserve (YBR) landscape is situated within such forests in the Democratic Republic of Congo (DRC). Surprisingly, given its proximity to the Congo River, the YBR is confronted with water issues. As part of its ecosystem function, the landscape is expected to reduce deterioration of water quality. However, environmental consequences are increasing due to conversion of its dense forest into other types of land use/land cover (LULC) in response to human activities. It is therefore important to check how the physicochemical quality parameters of water resources are influenced by landscape parameters—and to know if the population can adapt to this water vulnerability. To do this, we analyzed the watershed typology (including morphometric and LULC characteristics) and the physical and chemical parameters of water within the principal watershed’s rivers. We also analyzed data from surveys and the Yangambi meteorological station. We found that some landscape indices related to LULC significantly influence water quality deterioration in Yangambi. On average, each person in the Yangambi landscape uses 29–43 liters of water per day. Unfortunately, this falls short of World Health Organization standards regarding some parameters. The best fitted simple linear regression model explains the variation in pH as a function of edge density of perturbed forest, edge density of crop land and patch density of dense forest up to 94%, 92% and 90%, respectively. While many researchers have identified the consequences of climate change and human activities on these water resources, the population is not well-equipped to deal with them. These results suggest that water management policies should consider the specificities of the Yangambi landscape in order to develop better mitigation strategies for a rational management of water resources in the YBR in the context of climate change.

Highlights

Many scientists are increasingly noting the influence of land use patterns on the degradation or improvement of water quality [1,2]
Are much lower in the Lusambila watersheds, where they they havehave a tions of dense forest (DF) are much lower in the Isalowe and Lusambila watersheds, where a significant proportion of bare soil and residential (BSR), compared to Analysis of of the significant proportion of BSR, compared to Lobilo and Loweo watersheds
We based the assessment of the impact of land use/land cover (LULC) types on the physicochemical quality parameters of stream water and whether the population would be able to adapt to this vulnerability in the context of climate change

Summary

Introduction

Many scientists are increasingly noting the influence of land use patterns on the degradation or improvement of water quality [1,2]. Among other types of land use/land cover (LULC), dense tropical forest has been found to help improve the physicochemical quality of water at the watershed level. In addition to other services, these forests offer vital ecosystem services related to the regulation and purification of water resources. They improve the supply and quality of water used for the different needs of forest households [3]. DRC accounts for around 11% of total tropical rainforests worldwide and 60% in Africa [7] This constitutes a major asset in terms of the regulation and renewal of its water resources. Due to DRC’s low population density, its per capita water availability potential is very high: 15,000 to 70,000 m3 per person per year [9]

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Conclusion