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Land–cover change in the Ngerengere River

providing timber, non-timber forest products, and and 2013. Similarly, Côte d’Ivoire’s N’ZI watershed
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ecosystem functions that are crucial for agriculture, has experienced substantial forest and savanna loss due
clean water supply, and disaster risk reduction. to agricultural encroachment. These land use changes
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7,8
However, land use and land cover (LULC) changes have disrupted hydrological cycles, reduced infiltration,
(LULCCs), driven by deforestation, forest degradation, intensified sedimentation, and compromised river water
and the expansion of human activities – such as quality, posing risks to ecosystem services and rural
agriculture, infrastructure development, and fuelwood livelihoods. Understanding these dynamics is crucial
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extraction – have historically led to widespread land for integrated land and water resource management
cover loss on both local and global scales. 6,8-10 According across West African catchments.
to global assessments, the Earth lost approximately Globally, LULCCs are increasingly recognized as
4.4% of its forest cover between 1990 and 2020 – an a critical environmental challenge with far-reaching
area equivalent to about 178 million hectares – primarily implications for climate change, food security, water
as a result of anthropogenic pressures. 9 scarcity, and socioeconomic development. 9,11,24 These
For instance, in Africa, remote sensing data and changes significantly disrupt ecological processes,
field assessments from 2000 to 2020 show a continued particularly in sensitive areas such as river catchments,
decline in vegetation cover across many countries, where alterations in vegetation cover can degrade
with tropical and subtropical forest zones being the watershed functions, affect hydrological cycles, and
most affected. 11,12 This trend is largely fueled by the reduce water availability downstream. The impacts are
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conversion of forests into farmland, logging for timber not confined to the environment alone – and can directly
and charcoal, and infrastructure projects aimed at affect millions of people who rely on forests and natural
improving connectivity and economic growth. 12-14 While ecosystems for clean water, agriculture, energy, and
these developments contribute to short-term gains, they livelihoods. As river catchments degrade, the resilience
2,7
often come at the expense of long–term environmental of both ecosystems and communities weakens, further
sustainability. 15,16 The loss of forested land in Africa has exacerbating poverty, vulnerability to climate extremes,
led to the degradation of river catchments, disruption and the loss of biodiversity. Addressing LULCC in
of hydrological cycles, reduced rainfall infiltration, the context of protecting river catchments is therefore
increased surface runoff, and the siltation of rivers and essential for promoting sustainable development and
reservoirs – ultimately compromising water availability safeguarding human and ecological well-being. 19,25,26
and quality. 7,17-19 In West Africa, extensive vegetation In Tanzania, LULCC has emerged as a critical
decline has been documented between 2000 and environmental issue, especially within the Ngerengere
2020, particularly in tropical forest zones converted to River catchment located in the Wami–Ruvu Basin of
cropland, logged for timber or charcoal, or cleared for the Morogoro region. Over recent years, this area has
infrastructure – activities that often yield short–term experienced notable transformations in land cover,
economic gains at the expense of long-term ecological driven by deforestation, agricultural encroachment,
stability. 20-22 This trend is especially pronounced in urban development, and shifts in climate patterns. 14,27
countries, such as Nigeria, Ghana, Côte d’Ivoire, and These changes present serious threats to water
Burkina Faso, where deforestation and land conversion availability, biodiversity, and the sustainability of land-
have intensified over the past two decades. 20-23 Studies use practices. The Ngerengere River catchment is an
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highlight alarming rates of forest loss, notably in ecologically important zone, home to a wide variety of
the Guinean Forest Zone – one of the region’s most plant and animal species, and serves as a vital source
biodiverse ecosystems. For instance, in Nigeria, of natural resources for surrounding communities. 2,27,29
satellite data reveal significant forest reduction due to However, escalating human activities in and around
agricultural expansion, urban sprawl, and logging. In the catchment – particularly along riverbanks – have
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Ghana and Côte d’Ivoire, cocoa cultivation and illegal led to severe forest degradation, increased soil erosion,
timber harvesting have degraded vital watersheds such as and declining water quality. The conversion of forested
the Pra, Ankobra, and Bandama basins. 20,23 Specifically, areas into agricultural land has been a major contributor
Ghana’s Bonsa catchment lost over 0.3% of its forest to this degradation. 14,30 Furthermore, rapid urbanization
annually between 1986 and 2011, driven by mining in the Morogoro region has amplified the pressure on
and settlement expansion. In the Black Volta basin, land and natural resources, accelerating deforestation
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urbanization increased surface runoff by ~27% and and ecosystem decline. 13,31 Overall, one of the
reduced groundwater recharge by ~6% between 2000 primary factors driving vegetation cover change in the

Volume 22 Issue 5 (2025) 113 doi: 10.36922/AJWEP025180137