Journal Articles

Community Perspectives on Water Quality and Land Cover Change in the Micro-Catchments of the Nyando River Basin, Lake Victoria Basin, Kenya

2026-05-28T12:16:43Z

Community Perspectives on Water Quality and Land Cover Change in the Micro-Catchments of the Nyando River Basin, Lake Victoria Basin, Kenya Okungu, John; Okeyo, Owuor; Odenyo, Victor The Nyando River Basin, a critical part of the Lake Victoria Basin, faces increasing pressure on its water resources due to rapidly changing land cover and intensified human activities, which directly impact the quality and availability of water for local communities. Despite these challenges, limited research has documented community perspectives on how land cover dynamics influence water quality in the micro-catchments, creating a gap in evidence needed for participatory watershed management. Therefore, this study aims to assess community perspectives on water quality and land cover change in five micro-catchments of the Nyando River Basin within the Lake Victoria Basin, Kenya. The study employed a Citizen Science approach to gather community perspectives. The target population consisted of households and key stakeholders living within a one-kilometer radius of the Chebirirkut, Kimatkei, Kaplelmet, Sitoi, and Kibwareng micro-catchments. Apurposive sample of 20 respondents was selected, with this data supplemented through additional interviews and informal discussions to ensure a thorough collection of community perspectives. Data were analyzed using descriptive statistics and thematic analysis. Findings revealed strong linkages between land cover change and perceived water quality. Communities in Chebirirkut, where indigenous vegetation cover remained high (≈90%), reported consistently good water quality, attributing this to forest conservation. In highly impacted areas like Kimatkei and Kibwareng, communities reported significant deterioration in water quality, often characterized by brownish color during rains, and a decrease in water quantity, with streams occasionally drying up. They attributed these negative changes to intensive farming, cultivation near river banks, increased use of inorganic fertilizers, and the introduction of exotic tree species (e.g., Eucalyptus). Conversely, the well-conserved Chebirirkut micro-catchment, with intact forest cover, reported consistently good water quality and stable flow, validating the community's belief that conservation keeps water clean. Across all sites, respondents linked declining water quality to deforestation, poor farming practices, agrochemical use, and population-driven land pressure. Positive interventions such as tree planting, soil and water conservation structures, and forest protection were acknowledged where present. The key recommendation put forth by the communities was the urgent need for grass-roots sensitization and capacity building to promote sustainable agriculture and conservation practices, emphasizing the value of incorporating local knowledge into effective environmental management.

Assessment of Land Cover Changes in the Micro- Catchments of the Nyando River Basin within the Lake Victoria Basin, Kenya

2026-05-28T12:06:24Z

Assessment of Land Cover Changes in the Micro- Catchments of the Nyando River Basin within the Lake Victoria Basin, Kenya Okungu, John; Okeyo, Owuor; Odenyo, Victor The Nyando and Awach river catchments serve as vital headwaters draining into the Winam Gulf of Lake Victoria, an ecosystem increasingly threatened by sediment and nutrient loading. Despite its crucial role in regional hydrological stability, this region has undergone immense, largely unregulated anthropogenic pressure, leading to suspected widespread environmental degradation. The lack of long-term spatial data on the nature and level of land cover conversion constitutes a major barrier to formulating effective conservation strategies. To address this gap, this study quantified the extent, magnitude, and spatial dynamics of Land Cover Change (LCC) to assess the actual scale of environmental degradation. LCC was quantified through a time-series analysis of LANDSAT TM/ETM satellite imagery (1995, 2000, 2006, and 2012). A comparative micro-catchment classification (Uninterfered, Interfered, and Intervened sites) provided the environmental sampling framework. Images were processed using a Hybrid Supervised Classification approach to delineate four key thematic classes: Vegetation, Built-up Land, Water, and Open Land. Change detection matrices were then generated to calculate the absolute change, rate of change and conversion pathways. The results revealed significant vegetation decline in the Nyando catchment, characterized by a net loss of 54.2% of vegetative cover over the 17-year period. This loss corresponded with a marked increase in Open Land (≈41.5%) and Built-up Area (≈14.3%). The dominant conversion pathway, accounting for approximately 40.9% of all change, was the direct transformation of Vegetation to Open Land, signifying widespread, non-conservative agricultural expansion in the highlands. However, the Awach catchments registered comparatively lower net change, largely due to the replacement of indigenous forests with commercial plantations, which concealed ongoing ecological degradation. The significant

Modelling the impact of past and future land‐use changes on land cover degradation at territorial level in Eastern DR Congo

2026-03-06T08:13:03Z

Modelling the impact of past and future land‐use changes on land cover degradation at territorial level in Eastern DR Congo Nteranya, Jean Nacishali; Kiplagat, Andrew; Ucakuwun, Elias K.; Nzabandora, Chantal Kabonyi Land use and land cover (LULC) changes are recognized as drivers of environmental changes at the local, regional, and global levels. Detecting these changes is essential in developing land management plans and strategies. More particularly, the LULC changes constitute one of the sub-indicators used for setting the baseline for land degradation neutrality (LDN) planning and assessing the progress toward the sustainable development goal 15.3. This study aims to determine the implication of LULC dynamics on land cover degradation in Eastern DR Congo. This region has been subjected to uncontrolled LULC changes over the last three decades but the impact of these changes on land degra- dation has not been assessed yet at the territorial level. To fill this gap, the territory of Kalehe has been used as a case study to monitor the LULC changes during the 1987–2020 period based on the classification of Landsat images, to forecast the future LULC for the 2030–2070 period through the hybrid Markov-Support Vector Machine modeling, to determine the extent of land cover degradation associated with these changes and to assess the impact of bio- physical and socio-economic factors on the occurrence of land cover degradation using the binary logistic regres- sion model. The results reveal that the overall trends of LULC changes during the 1987–2020 period are the increas- ing of built-up area, shrubland, and cropland at the expense of forestland, wetland, and grassland. This situation is expected to continue in the future and contribute to the degradation of land cover within the study area. Under the current situation of LULC changes, 34.17% of the land has been subjected to potential degradation. Further- more, under the business-as-usual scenario 28.28%, 27.28%, and 33.65% of the land will be degraded by 2030, 2050, and 2070 respectively. This land cover degradation is more likely to occur in the proximity of roads, localities, highly populated areas, mining concessions, and high-altitudinal zones. Since the current land use system is unsustainable, there is a necessity to implement sustainable land management strategies that take into account the biophysical and socio-economic specificities of this region to reverse the problem of land cover degradation.

Modelling Habitat Suitability for African Elephants (Loxodonta africana) Preferred Forage in a Savannah Ecosystem in Kenya

2026-03-05T10:25:15Z

Modelling Habitat Suitability for African Elephants (Loxodonta africana) Preferred Forage in a Savannah Ecosystem in Kenya Kipkosge, Lynn; Kimanzi, Johnstone; Sudoi, Vincent Understanding the environmental determinants of habitat suitability for African elephants’ preferred forage plants is essential for effective conservation, especially in the face of climate change. This study assessed the current and future habitat suitability for elephant forage species within a savannah ecosystem in Kenya. An optimised Maximum Entropy (MaxEnt) modelling approach was employed using 152 spatially independent occurrence data points and eight noncorrelated environmental variables. The model used a Linear-Quadratic feature combination and a regularisation multiplier of 1.5. Occurrence data were collected through field surveys, while environmental layers were obtained from publicly available datasets including WorldClim, ASTER GDEM, USGS, HydroSHEDS, and OpenStreetMap. Future climate projections were based on the CanESM2 model under SSP245 and SSP585 scenarios for the periods 2041– 2060 and 2081–2100. Model performance was evaluated using the Area Under the Curve (AUC) of the Receiver Operating Characteristic (ROC), yielding strong results (AUC = 0.883 ± 0.007). Precipitation Seasonality (bio_15), Precipitation of the Driest Quarter (bio_17), elevation, and Land Use Land Cover (LULC) were the most influential predictors. Under current conditions, unsuitable habitats dominate the landscape (73.42%), while low, moderate, and high suitability zones are relatively limited. Future projections indicate continued dominance of unsuitable habitats with minor changes (1.28%–3.78%), slight increases in high and moderate suitability areas, and notable declines in low suitability zones across all climate scenarios. These findings highlight the vulnerability of forage plant habitats to climate change and underscore the need for climate-informed conservation strategies to ensure the long-term availability of key food resources for African elephants in this dryland ecosystem

MAPPING THE RESISTIVITY VARIATIONS IN THE SUBSURFACE SURROUNDING AT KIPKENYO DUMPSITE, ELDORET TOWN, KENYA

2025-12-09T05:54:39Z

MAPPING THE RESISTIVITY VARIATIONS IN THE SUBSURFACE SURROUNDING AT KIPKENYO DUMPSITE, ELDORET TOWN, KENYA koima, Robert; Nyaberi, D.M; Chibole, K.O A geophysical investigation of groundwater contamination within the solid waste disposal site was carried out at Kipkenyo dumpsite which is typically non controlled solid waste disposal site. Total of twenty six (26) VES survey points were conducted at measurements of between 20 to 30 meters between the (VES) points. The schlumberger array was used to collect data, Earth Imager 1D software were used in analyzing data obtained. The purpose of the research was to determine whether the presence of the landfill compromises the quality of groundwater within a vicinity of the dumpsite. Profile 6 and 7 in the southeast direction showing low resistivities indicating possible dissolution of heavy metals, from depths of 1.96 to 4.32 m, 29.65 to 47.75, 3.75 m to 9.00m and 17.45 m to 47.75 m respectively, High a resistivities at the eastern wing of the study area demonstrates uncontaminated compared to northwest, west and southwest which have low values of resistivities resulting to high level of contamination, this could be attributed to varying hydraulic conductivity depending on the composition of the solid waste in the landfill, compaction and soil contaminant interaction. The region 80 m from dumpsite to the northwest, west and southwest show low resistivities across the profiles’ depths Profiles 5 and 8 were used as control points done at about 100 meters from the dumpsite and presents resistivities’ ranges of 141.7 Ohm-m to 2616.2 Ohm-m suggesting its uncontaminated zone. The contamination runs to a depth of 47.75 m.

Review: Artisanal Gold Mining in Africa—Environmental Pollution and Human Health Implications

2025-12-08T10:34:23Z

Review: Artisanal Gold Mining in Africa—Environmental Pollution and Human Health Implications Ondayo, Maureene Auma; et. al. About nine million Artisanal and Small-scale Gold Mining (ASGM) workers in Africa and people living near ASGM activities are highly exposed to geogenic and anthropogenic potentially toxic elements (PTEs). Despite the hazards and risks posed by ASGM being well characterized, coordinated multidisciplinary environmental characterization with combined public health studies are limited, with often piecemeal and snapshot studies reported, as highlighted by this review. Furthermore, studies are often not connected with efforts to minimize hazards holistically. Given this, we systematically reviewed the scientific literature on human health hazards associated with ASGM in Africa through Google Scholar, Science Direct, and Pubmed databases. One hundred and seventy-three peer-reviewed papers published between 1996 and June 2023 from 30 African countries were identified. Toxicological environmental hazards were reported in 102 peer-reviewed papers, notably As, Cd, CN, Cr, Hg, Pb, respirable SiO2-laden dust, and radionuclides. Exposure to PTEs in human biomonitoring matrices and associated health impacts were documented in 71 papers. Hg was the most reported hazard. Gaps in research robustness, regulation and policy framework, technology, risk detection, surveillance, and management were found. Despite international and in-country mitigation efforts, ASGM-related hazards in Africa are worsening. This review paper highlights the need for coordinated action and multidisciplinary collaborative research to connect dispersed isolated studies to better characterize the associated disease burden associated with ASGM in Africa and sustainably maximize the wider benefits of ASGM whilst protecting public health and the environmen

Evaluation of Groundwater Potential Using Electrical Resistivity Method, in University of Eldoret, Uasin Gishu County, Kenya

2025-05-13T12:27:21Z

Evaluation of Groundwater Potential Using Electrical Resistivity Method, in University of Eldoret, Uasin Gishu County, Kenya Chelule, Franklin Kipkoech; Nyaberi, Daniel Mogaka; Kipkiror, Loice J. The deployment of electrical resistivity method in mapping the subsurface has been instrumental globally in understanding groundwater occurrence. In this study Vertical Electrical Sounding (VES) interpreted results have been instrumental in mapping the possible structural controls of groundwater in University of Eldoret. The apparent resistivity data collected from the area, was inverted by use of the AGI Earth Imager ID inversion automated computer program, resulting unto resistivities and thicknesses of geoelectric models. The analyzed VES data was further interpreted by curve matching technique whose results indicates the existence of curve types; H-type ρ1> ρ2 <ρ3; A-typeρ1<ρ2<ρ3; representing 3-Layer subsurface. There are four points mapped with each having five VES points, and the analysis shows distinctly a change from point to point. The analysis in general shows a deeper aquifer from the depth of about 206 metres to 251 metres. There also exists shallow aquifers though presents different depths from point to point, indicating a possible undulation in the subsurface which can be explained by possible existence of old land surfaces.

Lead and Cadmium Pollution: Implications for Health in Artisanal and Small Scale Gold Mining in Senegal and Kenya

2025-05-12T08:07:52Z

Lead and Cadmium Pollution: Implications for Health in Artisanal and Small Scale Gold Mining in Senegal and Kenya Agan, Leonard; et. al... Artisanal and Small-Scale Gold Mining (ASGM) is a prevalent activity, characterized by lowtech equipment and inadequate Occupational Health and Safety Standards (OHS). The ASGM is a significant source of Potentially Toxic Elements (PTEs), which can result in potential health risks to humans and the ecosystem. The interconnectedness between human and environmental health have gained global attention from scientific communities, public health and planetary health regarding human-environmental continuum’s safety. This study aimed at assessing human and environmental health risks associated with mine pollution in Kedougou region of South Eastern Senegal and Kakamega region in Western Kenya. Purposive sampling was used to collect waste ores, agricultural soil, residential soils and surface water samples were taken from Kedougou region while secondary data on similar matrices were used from Kakamega region. Descriptive statistics, figures and tables were used to present the result. Health risks assessment were achieved using Enrichment Factors (EF), Index of Geo-accumulation (Igeo), Pollution Index (HPI), and Ecological Risk Assessment Indices (ERI); to ascertain the source and the burden of health risk as a result of contamination in the two regions. Distinct geological and mineralogical compositions contributed significantly to the difference in concentrations of these Pb and Cd across Eastern and Western Africa regions. Further, geographic variation in background concentrations contributed significantly to the natural Pb and Cd levels in environmental media between the different locales. This research concluded that ASGM is one of the contributors to human and ecosystem health risks associated with Pb and Cd pollution. There is urgent need for comprehensive Occupational Health and Safety Standards; implementation and training of miners to safeguard human health while maintaining the livelihood in ASGM operations as well as proper control of mine waste disposal and conservation measures around the ASGM areas.

IIndigenous knowledge for Climate-Related early warning impact mitigation and disaster preparedness in Lower Nyando Basin, Kenya

2025-03-19T07:12:55Z

IIndigenous knowledge for Climate-Related early warning impact mitigation and disaster preparedness in Lower Nyando Basin, Kenya Raburu, Okoth Philip; et. al... Climate-related indigenous knowledge is essential as an early warning for mitigation of climate change impacts and for disaster preparedness. Whereas the knowledge is with the community, it is hardly disseminated due to lack of proper documentation and recognition of the same. The goal of this study conducted in Nyando Basin, Kisumu County, Kenya (where native populations are perennially vulnerable to climate variability) was to find out how indigenous knowledge could be harnessed to address persistent climaterelated challenges. Descriptive data was collected using observable early warning weather indicators linked to behavior of plants, animals, meteorological elements, celestial bodies and humans. A sample of 359 household heads was obtained by randomized purposive sampling from a population of over 10,000 farmers. Hypothesis testing was done using χ2 at 0.05 level of confidence. Triangulation was done by focus group discussions and key informants. Observed climate-related impacts in the last 30 years included increasing desertification (61.8 %), soil erosion (68.0 %), reduced soil moisture (80.2%) and increased weeds (82.2%). The impact of climate change on farming communities in terms of quantity, distribution and quality of livestock product and the quantity, distribution and quality of crop product. The length of rainy season was decreasing with a resultant effect on longer dry periods (p (χ2=83.333, df 19) = 0.042 at α 0.05). Climate change resulted to decrease in quantity, quality and distribution of livestock products as well as crop products. A significant relationship was observed between the production of maize and poverty level and also food security (F-value of 6.855 and pvalue of 0.000) at α 0.05. Proper documentation of knowledge base for predicting climate and weather events based on observations of animals, plants and celestial bodies would be handy to enhance community resilience to climate change.

Phytoremediation of Chromium and Lead-Contaminated Soil Using Putative Raphanus raphanistrum

2025-02-14T06:33:03Z

Phytoremediation of Chromium and Lead-Contaminated Soil Using Putative Raphanus raphanistrum Sherif, Salia S.; Simiyu, Gelas M.; Kinyua, Miriam G. Potentially toxic elements, including Chromium and Lead, naturally occur in the environment, however, human activities such as extensive farming, industrialization, and mining increase Potentially toxic element concentrations in soils. Hence, this study aimed to assess enhanced phytoremediation of Chromium and Lead-contaminated soils with putative mutant, Raphanus raphanistrum (wild radish). The putative plant was enhanced to phytoremediation of Chromium and Lead-contaminated soils. The soil physicochemical parameters pH, total organic matter, cation exchange capacity, and electrical conductivity determined were 5.20, 2.57%, 21.50 meq%, and 0.05 mS/cm, respectively. Raphanus raphanistrum seeds were treated with 0.00%, 0.25%, 0.50%, and 1.00% concentrations of colchicine to heighten growth and morphological development in enhanced phytoremediation of potentially toxic elements in soil. The treated Raphanus raphanistrum at 0.50% colchicine removed 226.69±1.22 mg/Kg and 236.95±0.82 mg/Kg of Chromium and 880.49±1.46 mg/Kg and 518.80±0.81 mg/Kg Lead in the first (M1) and second (M2) generations respectively. At the same treatment level, the putative plant hyperaccumulation potentially toxic elements at M1 and M2 generations absorbed 68.60% and 22.00% of Chromium and Lead, respectively. The plant bioaccumulated high amounts of metal elements, Chromium and Lead, capable of causing potential environmental and health concerns. This study finding contributes significantly to phytoremediation techniques in ecological restoration and recommends putative R. raphanistrum for Chromium and Lead polluted soil decontamination.