What the study found
The study found that stone quarrying along River Mutonga was concentrated near the river and was linked to major changes in land use, environmental conditions, and local livelihoods. Quarrying was described as having both positive effects, such as household income, and negative effects, including land degradation, vegetation loss, water pollution, and safety hazards.
Why the authors say this matters
The authors conclude that the findings point to the need for sustainable quarry management. They specifically mention post-extraction rehabilitation, environmental monitoring, and enforcement of land use regulations.
What the researchers tested
The researchers examined the spatial distribution, spatiotemporal dynamics, and ecological and socio-economic impacts of stone quarrying in Imenti South, Meru County, Kenya. They used GPS coordinates, high-resolution satellite imagery, Sentinel-2 images from 2015, 2020, and 2025, a Random Forest classifier in Google Earth Engine, and household surveys.
What worked and what didn't
The mapping identified 20 quarry sites in total: 11 active and 9 abandoned, with site sizes ranging from about 0.15 ha to 1.20 ha. Land use and land cover analysis showed quarry areas increased by 0.18 km² (61.8%), built-up areas by 0.17 km² (100%), and bare land by 2.23 km² (56.03) between 2015 and 2025. Residents reported income and community development benefits, but also environmental degradation and safety concerns, including accidents and hazards from water-filled abandoned quarries.
What to keep in mind
The abstract does not describe detailed statistical uncertainty, sampling limits, or validation results for the image classification. The summary is limited to one river corridor in Meru County, Kenya, so the findings are specific to that study area.
Key points
- Twenty quarry sites were mapped along River Mutonga, including 11 active and 9 abandoned sites.
- Quarry areas increased by 0.18 km² between 2015 and 2025.
- Residents reported both income benefits and negative environmental impacts from quarrying.
- Reported harms included land degradation, vegetation loss, water pollution, and safety risks.
- The authors call for rehabilitation, environmental monitoring, and land use regulation.
Disclosure
- Research title:
- Quarrying along River Mutonga expanded and affected land, water, and livelihoods
- Authors:
- Roystone Bundi, Brian Rotich, Dennis Ojwang, Kennedy Chumar, Azaria Stephano Lameck, Paul Njue, Harison Kiplagat Kipkulei
- Institutions:
- Chuka University, Chuka University, Chuka University, Chuka University, Jomo Kenyatta University of Agriculture and Technology, Kenya Industrial Research and Development Institute, Mbeya University of Science and Technology, University of Augsburg
- Publication date:
- 2026-03-10
- OpenAlex record:
- View
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