http://41.89.164.27:8080/xmlui/handle/123456789/226 2026-04-09T10:26:08Z http://41.89.164.27:8080/xmlui/handle/123456789/2507 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. 2024-01-01T00:00:00Z http://41.89.164.27:8080/xmlui/handle/123456789/2492 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 2025-11-01T00:00:00Z http://41.89.164.27:8080/xmlui/handle/123456789/2421 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. 2024-01-01T00:00:00Z http://41.89.164.27:8080/xmlui/handle/123456789/2416 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 2023-10-01T00:00:00Z http://41.89.164.27:8080/xmlui/handle/123456789/2345 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. 2024-01-01T00:00:00Z http://41.89.164.27:8080/xmlui/handle/123456789/2321 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. 2024-01-01T00:00:00Z http://41.89.164.27:8080/xmlui/handle/123456789/2210 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. 2024-01-01T00:00:00Z http://41.89.164.27:8080/xmlui/handle/123456789/2187 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. 2024-10-01T00:00:00Z http://41.89.164.27:8080/xmlui/handle/123456789/2170 Effects of Organic and Inorganic Fertilizers on Weed Diversity and Population in Tobacco ( Nicotiana tabacum L.) Farms in Migori County Nyantika, Martha; et. al... Tobacco (Nicotiana tabacum L.) is a significant cash crop in Migori County, Kenya, and plays a vital role in the local economy. However, the cultivation of tobacco is not without its challenges, one of which is weed infestation. Weeds in tobacco farms can compete with the crop for essential resources, such as water, nutrients, and sunlight, leading to reduced crop yields and quality. Effective weed management is crucial to maintain the productivity and profitability of tobacco farming in the region. Therefore, the study objective was to analyze the effects of inorganic fertilizer (DAP fertilizer) and organic manure on population density of weed species, as well as the species diversity of the weed population under tobacco crop. A study was conducted in Migori county, employing a randomized complete block design, with four locations (Masaba, Mabera, Kakrao, and Bondo) and three different treatments, each of which was replicated three times. These treatments comprise of various types of fertilizers, including inorganic and organic variants, along with a control group receiving no fertilizer. The study's primary focus was on assessing weed population, leaf yield, and alterations in soil physico-chemical properties. During the second weeding phase, Malva verticilate was counted, with a mean value of 10.42, in both Mabera and Masaba. However, no instances of Malva verticilate were recorded in the other two sites. Sida alba acuta and Richardia brasilium R. brasiliens were counted in all four locations, with mean values of 6.22 and 28.21, respectively. The data obtained was subjected to statistical analysis using the General Linear Model (GLM) and analysis of variance (ANOVA) within the GENSTAT 12, 2012 statistical software package. To determine significant differences, means were separated using Tukey's test at a 5% level of significance. Results of the study showed that the dominant weed flora among monocot weeds were Eleusine indica L., Cynodon dactylon L., Digitaria sanguinialis L . and Chloris barbata L . Among dicot weeds, Phyllanthus niruri L., Amaranthus viridis L., Euphorbia hirta L., Heliotropium indicum L., Gynandropsis pentaphylla L.,Launaea nudicaulis L. and Oldenlandia umbellata L. were found as major weeds. Cyperus rotundus L. was the only sedge found associated with tobacco crop across the four sites. This was common under inorganic fertilizer treatments, indicating that TF treatment suppressed growth and development of sedges. Results indicate that weed distribution and population under inorganic and organic fertilizer is related not only to the soil nutrient and physical content, but also to competition from the crop for water and light. Therefore, it is recommended to consider a combination of inorganic fertilizer and organic manures to optimize weed control and soil health in tobacco farming. 2023-01-01T00:00:00Z http://41.89.164.27:8080/xmlui/handle/123456789/2015 Water Hyacinth, an Invasive Species in Africa: A Literature Review Lubembe, Sharon Indasi; et al. Water hyacinth is without a doubt the water invader that causes the most harm to water bodies. Water hyacinths originated from Eastern Mediterranean, West Asia, and Central Asia; they are cultivated and loved worldwide. According to reports, water hyacinth has anti-inflammatory, antifungal, and antibacterial properties. The plant extracts can also be used to treat cholera, sore throats, and snake bites, as well as to scent hair. Water hyacinth Pontederia crassipes (Eichhornia crassipes) has proliferated rapidly in African inland waters, posing numerous threats to fisheries by reducing the existence of some species; water quality by lowering levels of dissolved oxygen; human health and the environment by introducing various disease-causing pathogens and harbouring dangerous animals. The hyacinths further impact human activities by blocking waterways for fishing and destroying habitat for some fish to bread properly. Tourism and navigation are also affected by limiting access to recreational areas, especially for boat cruising. Fishing; effects on fishing activities and effect on plankton production, which is the main food. Different control methods have been utilised and others suggested in Africa, although it has not been fully controlled as it is highly reproductive and still a menace in African inland waters. The most commonly used control measures are biological and physical controls. As a recommendation, all methods should be used in water bodies to reduce its spread as quickly as possible although with caution on chemical methods. In relation to water hyacinth and its effects on terrestrial animals, there is still a need for much research to still be done; however, it is an aquatic plant that is not wanted in many places does not mean it should be eradicated. Its use to produce biogas could be helpful in reducing the challenges that come with it. 2023-07-01T00:00:00Z