http://41.89.164.27:8080/xmlui/handle/123456789/200 2026-04-03T15:37:02Z http://41.89.164.27:8080/xmlui/handle/123456789/2516 DETERMINATION OF THE EXTEND OF GROUNDWATER CONTAMINATION WITHIN THE VICINITY OF KIPKENYO DUMPSITE IN ELDORET MUNICIPALITY, UASIN GISHU COUNTY, KENYA KOIMA, ROBERT The increasing demand for groundwater as a primary source of water supply has raised concerns about its vulnerability to contamination, particularly in areas surrounding unmanaged dumpsites. Kipkenyo Dumpsite in Eldoret Municipality, Uasin Gishu County, Kenya, presents a potential risk of leachate infiltration into groundwater, threatening water quality and public health. This study aimed to evaluate the impact of leachate contamination in groundwater quality by integrating geoelectrical resistivity surveys and physicochemical analyses. The specific objectives were to determine the physicochemical characteristics of groundwater contamination, map the spatial distribution of leachate contaminant plumes using geoelectrical methods, analyze the vertical and horizontal flow dynamics of leachate, and assess the hydrogeological and environmental factors influencing leachate migration and contaminant transport. This study was anchored in Dacy’s Law developed Darcy's Law in 1856 which is based on experiments that studied the flow of water through sand filters. The study was conducted in the Kipkenyo Dumpsite vicinity, focusing on shallow wells and boreholes used by the local community. A descriptive research design incorporating both geophysical and laboratory analyses was adopted. The sample size comprised groundwater samples were collected from selected wells, with sampling points determined through stratified random and purposive sampling techniques. Physicochemical parameters, including pH, electrical conductivity (EC), total dissolved solids (TDS), nitrates, chlorides, phosphates, sodium and potassium, were analyzed using standard laboratory procedures. The geoelectrical resistivity survey employed two-dimensional (2D) and three-dimensional (3D) resistivity imaging to map subsurface contamination zones. Data analysis involved statistical techniques such as one-way ANOVA to assess spatial variations in water quality parameters, and geophysical inversion modeling to interpret resistivity variations indicative of leachate infiltration pathways. Results indicated that groundwater quality parameters varied across different wells, with pH levels ranging from 5.94 to 11.70, electrical conductivity from 42 to 113 μS/cm, total dissolved solids from 21 to 57 ppm, nitrate from 0.01 to 0.67 mg/L, chloride from 1.90 to 4.40 mg/L, phosphate from 0.26 to 1.04 mg/L, sodium from 5 to 10 mg/L, and potassium from 6 to 58 mg/L, suggesting potential leachate contamination. Further, the findings revealed significant variations (p<0.05) in physicochemical parameters across different wells, with some locations exhibiting elevated ion concentrations linked to leachate percolation. While most parameters remained within World Health Organization (WHO) and National Environment Management Authority (NEMA) limits, localized areas displayed elevated levels of pH and ion concentrations, indicating contamination hotspots. Geoelectrical resistivity imaging identified subsurface zones with low resistivity values, suggesting potential leachate infiltration pathways and groundwater contamination zones. The findings further indicated that groundwater contamination was not uniform across the study area, with hydro geological conditions influencing contaminant transport and distribution. The study concluded that leachate infiltration from Kipkenyo Dumpsite may pose a potential risk to groundwater quality, with localized contamination requiring continuous monitoring. The study recommended the implementation of proper waste management strategies, regular groundwater quality assessments and the establishment of protective buffer zones to mitigate contamination risks. Additionally, future research should incorporate seasonal variations to better understand leachate dynamics under different climatic conditions 2025-01-01T00:00:00Z http://41.89.164.27:8080/xmlui/handle/123456789/2289 MODELING LAND DEGRADATION IN UPPER TURKWEL WATERSHED AND IMPLICATIONS ON THE SUSTAINABILITY OF THE TURKWEL DAM RESERVOIR KIPKEMOI, TOROMO AMBROSE Sediment accumulation in water reservoirs with consequent shortening of the reservoir life is a growing global problem,the worst scenarios are common in tropical countries like the study area Turkwel watershed in Kenya. The study aimed to determine the land cover changes in the watershed. These would further answer how it affected land degradation and sediment accumulation in the reservoir and proposed mitigation measures. The study also considered the changing land use and land degradation patterns that have taken place in the catchment by studying periodic Landsat/satellite imagery. The studies established that bare land in the watershed between the last four decades of 1987 to 2017 increased insignificantly by (1.05%)/62 km2 (F 0.05 (1, 2) =12.49, p=0.0716), reinforcing the reality of global warming and climate change as a precursor to more soil erosion. The forest and agricultural land declined by 73 km2 (-1.24%) and 116 km2 (-1.97%), respectively, attributed to climate change and land pressure from the increasing population. The grassland increased insignificantly between 1987 to 2017 by 120.26 km2 (F 0.05 (1, 2) =1.95, p=0.2975). More farmers embraced livestock production through enclosures as a source of livelihood while abandoning crop farming. SWAT model studies in the watershed revealed that the area under medium to very high erosion rates rose to 1940 km2 (33%) in the 5900 km2 compared to 1290 km2 (22%) in 1982. Soil erosion was increasing and called for more conservation efforts on erosion hot spots and a function of soil vulnerability. The soil loss and Best Management Practices (BMPs) determined using standard runoff plot experiments on a 10.5% land slope farm showed clear benefits of integrated approaches. The Land Use/Land Cover changes (LUCC) studied using Landsat imagery, remote sensing, and Arc View GIS established that Runoff was reduced by retention ditches more than pasture reseeding. The highest significant difference in mean soil losses (using STATGRAPHICS) was between runoff plots with terraces and reseeded with Pokot Rhodes grass in comparison with no conservation (F0.05 (3, 220) =13.23, p=0.0001) with a maximum mean significance difference between the plot and the control plot/or no treatment plot with the variation of (78.81±29.22 kg/ha/storm). The field with Pokot Rhodes only had the second-lowest soil loss and indicated, that growing pasture was a cheap single conservation option. The best management Practice involving enclosures with an integrated ecosystem approach using agronomic, physical, and cultural measures was most effective with the extra benefits of ensuring sustainable production and environmental conservation. The study on the perception and adoption of introduced Soil and Water Conservation (SWC) strategies suggested that 98% of the farmers knew the accruing benefits of soil conservation but low adoption and sustainability. There was a need to intensify farmer's agricultural extension services. Some 32% of the farmers acknowledged stopping conservation activities at the end of the project support and this called for further research to establish the reasons. Using the four indices in modelling river flow at Turkwel, the flow data was consistent with the criteria for a monthly time step (R 2 =0.58, NSE=0.56, RSR=0.66 & PBIAS=10.9%). The SWAT model was therefore applicable to the catchment and the impact analyses. 2024-01-01T00:00:00Z http://41.89.164.27:8080/xmlui/handle/123456789/2266 RELATIONSHIP BETWEEN FLUORIDE LEVELS AND PHYSICALCHEMICAL PARAMETERS IN SELECTED MEDIA IN UPPER RIVER NJORO CATCHMENT NAKURU COUNTY, KENYA KIPTOO, SANGA JACOB Water is vital for life, but its quality determines its suitability for consumption. In 2020, 2 billion people lacked safe water services. Fluoride in water can be beneficial or harmful; the World Health Organization (WHO) recommends a maximum of 1.5 mg/L to prevent health risks. Globally, fluoride contamination is a problem, especially in India, China, and Africa. In Kenya's Rift Valley, high fluoride levels cause fluorosis. This study was conducted to assess fluoride levels in the Njoro catchment, Nakuru County, Kenya, due to concerns about potential health risks from elevated fluoride levels in the region. Water sources in the River Njoro catchment have varying fluoride concentrations, posing risks of skeletal and dental fluorosis. The study assessed fluoride levels in sediments, springs, and river waters in the upper River Njoro catchment, Nakuru County, guided by the following objectives: determining fluoride levels in sediments, springs, and river water, analyzing pH, temperature, electrical conductivity, and total dissolved solids in springs and river waters, and investigating the relationship between fluoride levels and physical-chemical parameters. This study assessed fluoride levels in the upper River Njoro catchment area, spanning from Nessuit upstream to Tumaini Bridge downstream. A longitudinal profile survey design was utilized, incorporating stratified sampling across upper, middle, and lower catchments. Data were collected from fifteen sites, including river water, spring water, and sediment samples, during both dry and wet seasons. Water and sediment samples were analyzed at the University of Eldoret for fluoride and physical-chemical parameters. Sampling involved triplicate collections, with physical-chemical measurements taken in situ and fluoride concentrations determined using ion-selective electrodes. Sediment samples were collected and processed following standardized methods. Statistical analysis, performed using Genstat software, involved ANOVA and correlation statistics to identify significant differences and relationships between fluoride levels and physical-chemical parameters. River water fluoride concentrations ranged from 0.38 to 1.77 mg/L, with the highest mean at site S8. River sediments showed fluoride levels between 0.50 and 2.91 mg/kg, with higher concentrations in lower strata. Spring water fluoride ranged from 1.20 to 2.44 mg/L, while sediments at spring sites had levels from 0.77 to 1.55 mg/kg. This study revealed significant variations in fluoride levels across river and spring waters in the upper River Njoro catchment, with some sites exceeding WHO standards. Fluoride levels negatively correlated with pH and positively with total dissolved solids (TDS) and electrical conductivity (EC). Spring water generally had higher fluoride concentrations than river water, suggesting geological or hydrological influences. The findings underscore the urgent need for targeted interventions to mitigate fluoride contamination and ensure safe water access for the local population. Continuous monitoring and remediation efforts, alongside public awareness campaigns, are essential to prevent further exposure and protect community health. 2024-01-01T00:00:00Z http://41.89.164.27:8080/xmlui/handle/123456789/1796 Water quality and ecology of Lake Kanyaboli, Kenya: Current status and historical changes Kondowe, Benjamin N.; etl.al... Small waterbodies are the most threatened freshwater habitats because of the large ratio between their size and the catchment they drain. The present study assessed the current and historical changes in the physical, chemical and biological variables of Lake Kanyaboli, a satellite lake on the northern shores of Lake Victoria in west -ern Kenya. Primary and secondary data on pH, electrical conductivity (EC), dissolved oxygen (DO) concentration, temperature, Secchi depth (SD), and nitrate (NO−3), nitrite (NO−2), ammonium (NH+4 ), soluble reactive phosphorus (SRP), total nitrogen (TN), and total phosphorus (TP) and chlorophyll-a (Chl- a) concentrations were utilized in the present study. The results indicated Secchi depth and chlorophyll-a were the most erratic of all the analyzed environmental variables studied, exhibiting a range of 0.69± 0.29– 0.87 ± 0.34 m and 9.03 ± 0.81– 34.97 ± 3.36 μg/L respectively. Two- way ANOVA yielded no significant interactions between sampling sites and seasons for all the variables. Except chlorophyll-a, there also were no significant differences among the sampling sites for the studied variables. Seasonality yielded significant differences for Secchi depth, dissolved oxygen and chlorophyll-a. The Carlson Trophic Index for Chl- a and SD indicated Lake Kanyaboli is currently eutrophic, while the TP concentra-tion indicated hypereutrophic conditions. The lake, however, has fluctuated betweeneutrophic and hypereutrophic conditions over the past years. Although historical water quality data for the lake is scanty and infrequent, most physical and chemical variables reflected anthropogenic effects on a temporal scale. Interestingly, despite its eutrophic status, the general lake condition is still relatively good, attributable to the buffering effect from the extensive macrophytes fringing it. The present study identified nutrient loading, wetland reclamation and connectivity with the Yala River through a feeder canal as the management issues of critical concern. Accordingly con -tinuous monitoring of the lake's water quality to detect anthropogenic effects is rec -ommended for management intervention purposes. 2022-01-01T00:00:00Z http://41.89.164.27:8080/xmlui/handle/123456789/1745 Mapping Landslide Susceptibility Along the Nandi Escarpment in Malava Sub-CountyKakamega County, Kenya Chepkosgei, E.; Ucakuwun, E. K.; Nduru, G. M. Landslidesmay occur in hilly terrain due to a combination of factors like deforestation, heavy precipitation, slope steepness and gravity, land use and cover. Whenever they occur, they may result in disasters such as loss of property and/or life. The frequency of landslidesin any area may be high if all the factors that trigger them are prevalent. The main objective of this study was to determine the factors that influence the occurrence of slope failure over space and time and produce a landslide susceptibility map of the Nandi Escarpment in Kabras area of Malava Sub-County. It also presents the capability of a Remote Sensing and GIS based approach to mapping the susceptibility of hilly terrains, with the Nandi escarpment as a case, to slope failure. A slope failure susceptibility map was used to help in identifying strategic points and geographically critical zones thatare prone to landslide risks. The study involved generation of landuse/ landcover maps extracted from Satellite Images, which were taken in the years 1973, 1995 and 2006. SRTM DEM 90m was used in generating slope and contour maps of the area. Soil maps were obtained as secondary data from Moi University Soil Laboratory and Soil Survey of Kenya, while rainfall maps were obtained from the Kenya Meteorological Department (KMD), Kakamega County. A slope failure risk map of Kabras region was produced by overlaying all thematic maps and analysis using GIS was conducted after assigning appropriate ranks and weights to respective variables. Focused groupsdiscussionswere used in data collection and probing historical information on land use changes in the area. The result is a map showing zones with varying degrees of susceptibility to slope failureandslopes steeper than 54owasmore susceptible to slope failures. It is opined that such a map will enable decision and policy makers to identify and implement suitable mitigation measures, with hopes of forestalling future losses in life and property in the area of study.Settlement should belimited to slopes of less than 24osince, according to this study, slopes higher than this are prone to sliding.There is needfor Kenya ministry of lands and physicalplanning to ensuresustainable land use activities are conducted in the slopes of various degrees. 2022-01-01T00:00:00Z http://41.89.164.27:8080/xmlui/handle/123456789/1652 On-Site Runoff Management, Challenges and Prospects in Amalemba, an Urban Informal Settlement in Kakamega Municipality, Kakamega County, Kenya Musonye, P. K.; Ucakuwun, E. K.; Munyao, T. M. This study investigated the challenges and prospects of on-site runoff management in Amalemba informal urban settlement in Kakamega Municipality, Kenya. The study followed a qualitative research design. Visual observations, photography, individual and focus group interviews were used to collect data. The findings indicate that on-site and institutional practices complemented each other in management of runoff. This study therefore affirmed the importance of meaningful participation of residents in runoff management interventions and approaches that sustain ‘socio-human’ capacity for response in relation to impacts of runoff in informal urban settlements. In conclusion, the benefits of catchment-scale model for runoff management, the potential of green infrastructure and the necessity for policy transition to sustainable drainage systems in Amalemba informal urban settlement are of critical importance. 2022-06-01T00:00:00Z http://41.89.164.27:8080/xmlui/handle/123456789/1596 ANALYSIS OF SPATIAL AND SEASONAL VARIATIONS OF WATER QUALITY USING STATISTICAL, CCME-WQI AND GIS METHODS IN NAKURU MUNICIPALITY, KENYA KELI, MARGARET MWIKALI Nakuru Municipality lies in the larger Lake Nakuru basin where the natural chemistry of its watershed is characterized by high levels of inorganic salts posing a significant problem to water resources. River and ground waters are the primary sources of drinking water for the municipalities’ population but despite their significance, there are limitations to the availability of a robust database that can describe their quality status in a reliable way. Information that can explain spatial and seasonal variations of river and ground water quality is not sufficient. This study targeted to bridge this gap by adopting a quantitative research design. Stratified random sampling was applied in the study of pH, electrical conductivity, and levels of fluoride selenium, chloride and cadmium. Thirty eight sampling points and three sampling periods/seasons were selected for this study. The seasons were put in three groups: group 1: Transition Period (TP), group 2: Short Rain Period (SRP) and group 3: Dry Period (DP). The data were analyzed, processed and interpreted using SPSS software Version 22.0, Microsoft window Excel tool, statistical, Geographical Information Systems (GIS) and Canadian Council of Ministers of the Environment Water Quality Index (CCME-WQI) methods. Water quality data were presented as mean values and evaluated based on guideline values to assess its suitability for drinking. Spatial and seasonal variations of examined parameters were descriptively analyzed. The results showed significant spatial and seasonal variations in some of the examined water variables (pH, chloride, fluoride, selenium, cadmium and electrical conductivity). Kruskal - Wallis H test was applied to test for seasonal variation in mean concentration values of water parameters where results were reported at 0.05 level of significance. Seasonally, the results indicated a statistically significant difference between the means of pH (P = 0.001) and cadmium (P = 0.000) but no significant difference for electrical conductivity (P = 0.130), selenium (P = 0.981), fluoride (P = 0.293) and chloride (P = 0.228) in ground water. Post hoc results showed significant existence of mean difference in pH between the TP and DP (P = 0.000) and TP and SRP (P= 0.006) while for cadmium there existed significant mean difference existed between TP and SRP (P = 0.001) and TP and DP (P = 0.000). For natural river water samples, Kruskal - Wallis H test results showed existence of significant differences between the means of pH (P = 0.050) and electrical conductivity (P = 0.008). However chloride (P = 0.629), cadmium (P = 0.122), fluoride (P = 0.105) and selenium (P = 0.472) did not show any significant difference. Post hoc results showed existence of significant mean difference in electrical conductivity between TP and DP (P = 0.004) and SRP and DP (P= 0.016) while for pH significant mean difference existed between TP and DP (P = 0.034) and SRP and DP (P = 0.34). Spatial distribution maps gave a pictorial representation of the spread of water quality parameters at different sampling points. Based on the CCME-WQI, index values for drinking water quality of river and ground water samples were calculated in a range of 20.94-39.69 and ranked as poor. Selenium, cadmium and fluoride were taken as important parameters impacting water quality as their concentrations were elevated. Aquifer geological formations and water quality characteristics showed spatial variation among the boreholes. Considering all examined variables, correlation results showed that correlation coefficient (r) values ranged from -0.85 to 0.70 in river water and -0.87 to 0.56 in ground water. The study concluded that the quality of river and ground water of the study area was mainly influenced by geological hydrogeological settings of the area, not potable and need proper treatment before consumption. 2022-01-01T00:00:00Z http://41.89.164.27:8080/xmlui/handle/123456789/1539 RUNOFF GENERATION, IMPACTS AND MANAGEMENT PRACTICES IN AMALEMBA URBAN INFORMAL SETTLEMENT, KAKAMEGA MUNICIPALITY, KENYA MUSONYE, PATRICK, K. The study was carried out in Amalemba informal urban settlement within Kakamega municipality, Kenya. It concerned environmental impacts of uncontrolled runoff in the environmentally vulnerable low income settlement. Management of runoff is a significant component towards the sustainability of a sound urban environment infrastructure. Runoff management is imperative in urban informal settlements since it enhances a healthy surrounding. This study identified human and physical features that influence runoff generation, determined influence of rainfall on runoff discharge, influence of slope and ground cover on runoff discharge, effects of runoff; and investigated runoff management measures in Amalemba informal urban settlement. The study followed a quasi-experimental research design. Runoff discharge measurements, visual observations, photography, individual and focus group interviews were used to collect data. Runoff from bare ground, 50% grass cover and 100% grass cover were compared using thirty rainfall events during long rains in April/May 2020. Runoff volume was collected using the Gerlach trough setup, the precise volume of discharge was measured using a graduated one litre measuring cylinder. Data from interviews with respondents was analyzed according to themes while data from the Gerlach trough setup was analyzed using inferential statistics. The rainfall-runoff relationship for Amalemba informal urban settlement indicates a statistically positive significant correlation between daily rainfall and runoff volume with r = 0.9822 for 100% grass cover, for 50% grass cover r = 0.9672 and r= 0.9934 for bare ground respectively with p-value <0.0000001 for all the three surfaces. Bare ground coupled with steeper slope produced the highest runoff while the surface with 100% grass cover yielded the lowest runoff. The results show that vegetation cover is better at protection of the soil against erosion and reduction of runoff than bare ground. Runoff produced adverse effects such as flooding, mini landslides, soil erosion, and blockage of drains as a result of bad solid waste disposal mechanisms and destruction of shacks, farmland and roads. On-site and institutional practices complemented each other in management of runoff. This study emphasizes meaningful involvement and participation in management of runoff; adopting methodologies which withstand both social and human capabilities ranging from controlling and managing runoff to the effects of runoff in informal urban settlements. Runoff management at the catchment level, appropriate use of green infrastructure and the formulation of policies aimed at development of sustainable drainage systems in Amalemba informal urban settlement is of critical importance. 2021-01-01T00:00:00Z http://41.89.164.27:8080/xmlui/handle/123456789/1492 EFFECTS OF GEOLOGICAL VARIABILITY AND SELECTED PHYSICAL PARAMETERS OF WATER QUALITY ON FLUORIDE LEVELS IN RIVER NJORO CATCHMENT, KENYA Ontumbi, George Morara Fluoride levels higher than the World Health Organization (WHO) recommended levels of 1.5 mg/l have to raise serious health issues. Therefore fluoride contamination is a pertinent matter that calls for concern by all people and government especially in countries where the phenomenon of volcanicity has been experienced. The study sought to analyse the effects of geological variability and selected physical parameters of water quality on fluoride levels in River Njoro catchment. The study was guided by the following objectives: to determine the relationship between fluoride levels and surface geology in River Njoro catchment, to determine the relationship between borehole stratigraphy formation matrices and fluoride levels in borehole water in River Njoro catchment, determine the relationship between pH, temperature and Electrical conductivity and fluoride levels in groundwater in River Njoro catchment and finally model spatial variation and distribution of fluoride levels in ground water in the River Njoro catchment. The study sought to highlight the levels of fluoride and give recommendations on identification and delineation of potential sites for safe groundwater for the local population and advice on the water treatment and de fluoridation strategies. Past researches on River Njoro catchment gave much emphasis on land use/cover changes and strong condemnation on elevated fluoride levels in the Njoro catchment and therefore the gap in this research was based on the integration of geological variations and geological stratigraphy of River Njoro catchment and ultimately produce a predictive trend. This study adopted purposive longitudinal survey and quasi experimental research designs. In this research borehole and river water, soil and rock samples from designated points along the River Njoro and its tributaries were collected for laboratory analysis of fluoride levels. The research adopted descriptive and correlation statistical analysis. The sources of data included: field surveys which were used to collect data about the fluoride levels, the remotely sensed, GIS and Geostatistical interpolation, content analysis of the literature on the geology of the Njoro catchment and the hydro-meteorological and geological characteristics data. From the results of the study it was observed that: the fluoride levels in River Njoro catchment varied with the geology of the catchment and fluoride levels in groundwater depended on the borehole stratigraphy matrix, the selected physical parameters of water quality (pH, Electrical Conductivity and temperature) had a significant statistical relationship with fluoride levels in River Njoro catchment and land use/cover changes and variations in the borehole depths. The results through Geostatistical interpolation also observed that there is varied distribution and variation of fluoride levels in River Njoro catchment. Therefore geological variations, borehole depths and lithological formations were manifested in the fluoride level variations in the water and rock sampling points that were located either upstream, midstream and downstream of the River Njoro catchment. Finally the study recommends isotopic analysis of water samples from the sources of water in River Njoro catchment to assist in tracing their origin, contamination of fluoride and fluoride enrichment pathways and water quality alteration within the catchment. 2020-01-01T00:00:00Z http://41.89.164.27:8080/xmlui/handle/123456789/1435 Variation of Fluoride Levels in Surface Geology: A Study of River Njoro Catchment, Kenya Ontumbi, George. M.; Ucakuwun, Elias. K.; Munyao, Thomas, M. Fluoride levels in water that is higher than the World Health Organization (WHO) recommended levels of 1.5mg/l have raised concerns to the health of human. Subsequently fluoride contamination in water is a pertinent matter that calls for concern by all people and government. This study sought to investigate variation of fluoride levels in surface geology in river Njoro catchment. This study adopted purposive longitudinal survey research designs. In this research, rock samples were collected from 11 purposively selected points along the river Njoro and its tributaries to analyse fluoride levels in the laboratory. The research adopted descriptive data analysis in evaluating fluoride changes as contained in the rocks. The study observed that despite different types of volcanic rock outcrops along Njoro River, there were minimal variations in the levels of fluoride in the river Njoro. The study identified Superficial Deposits of Volcanic Soils with highest fluoride levels (1.575 mg/l) while eutracite Welded Tuffs had the lowest fluoride levels (0.678 mg/l). In Conclusion the rocks within the River Njoro catchment have insignificant contribution to the known elevated fluoride levels contained in sub surface and water in the ground in Njoro River catchment. 2020-01-01T00:00:00Z