MST- Department of Spatial and Environmental Planning
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Item Exploring the Potential of Sentinel-2 Broadband Spectral Features for Discrimination of Invasive Lantana Camara L. Among Co-Occurring Species(South African Journal of Geomatics, 2025-07) Waititu, Julius Maina; Mundia, Charles Ndegwa; Sichangi, Arthur W.Lantana camara L. (LC), an alien invasive plant species, negatively impacts natural habitats globally. In East Africa, it is one of the habitat’s transforming species that requires urgent mapping to support conservation actions. Its spatial distribution has not been adequately established, especially within forest habitats. In this study, we sought to identify Sentinel-2 broadband spectral features that could discriminate LC from co-occurring vegetation in a forest habitat. In-situ leaf-level hyperspectral measurements of LC and co-occurring species, namely, Neonotonia wightii (NW), Cucumis maderaspatanus (CM) and Ocimum gratissimum (OG), were collected in a one-hectare site in the Muringato forest area during the dry and wet seasons using two handheld spectroradiometers covering wavelength ranges of between 340–820 nm and 635–1100 nm. The leaf-level reflectance measurements were used to simulate Sentinel-2 wavebands, which were subsequently used to compute new band combination indices of type Normalized Difference (ND), Simple Ratio (SR), Difference (D) and Inverse Difference (ID) and published Sentinel-2 multispectral indices. The most spectrally significant features were selected using the Boruta and the Guided Regularized Random Forest (GRRF) methods. Jeffries– Matusita (JM) distance analysis was used to quantify the spectral separability of species class pairs using selected spectral features. The findings of this study showed that the selected Sentinel-2 spectral features that produced perfect separability accuracies of ≥97% for LC class pairs consisted of mostly the newly developed band combination indices and, to a lesser extent, the published Sentinel-2 indices. Notably, the separability analysis produced a unique set of spectral variables that accentuated the spectral properties of LC class pairs in both seasons and further pointed to the influence of the seasonal spectral variabilities of the species. Moreover, the Boruta method resulted in the selection of fewer spectral variables (2–12 variables) than the GRRF method, which resulted in the selection of two to19 variables for species class pair separability. Overall, the separability results demonstrate the potential of separating LC from other vegetation with freely available Sentinel-2 image data. The significant spectral variables identified in this study could be used for the seasonal mapping of LC and for further aid in the early detection and targeted management of the species in affected forest habitatsItem Environmental Consideration of Inter-Basin Water Transfer Scheme in Northern Water Collection Tunnel, Murang’a County, Kenya(2023-06) Kamau Joseph M.Rapid urbanization has led to significant challenges in ensuring adequate water supply with minimal adverse impacts on the catchment areas, The adverse impacts on catchment areas affect more than 18 million people in Kenya and are predicted to affect six billion people globally by 2050. The Nairobi Northern Water Collector Tunnel was a flagship National Government Project aiming to address the perennial water shortages in Nairobi City. Diverting water from rivers to collect at the dam significantly affect those downstream as they are limited to clean and enough water. For that reason, the project does not achieve the desired goals, therefore Proper understanding of environmental considerations to be observed by stakeholders is the key in solving the impacts. It is therefore imperative to assess environmental considerations to ensure sustainable water supply. The objectives of the research are to determine the hydrological issues related to the Nairobi tunnel project in the project area, to assess environmental considerations fo r addressing bulk inter-basin water transfer schemes and to examine techniques adopted by the NCT project in addressing the concerns. The study location for the research was in Murang’a County, particularly Maragua, Gikigie and Irati areas. Primary data was obtained from key informant’s interviews, questionnaires and observation checklists, Secondary data was obtained from reports, historical data and records. Purposive sampling technique was applied for key informants® interviews while stratified sampling was applied for household questionnaires. Data analysis were done using SPSS software version 24 where the questionnaires are coded, analysed and interpreted. Presentation of data was done in form of tables and figures. T-test analysis were done to assess the relationship between the respondent’s demographic attributes and their responses regarding the environmental consideration. The study was used in decision making on appropriate interventions on hydrological issues related to water collection points. Most of them have basic education, signifying that the project would be a significant boost to their economic development through employment, increased business opportunities, increase water available for farming. The findings further demonstrated that partial river diversion was the primary Wwater abstraction technique stakeholders in the NCT project adopted. It involved building tunnels to divert most of the river’s waters to dams for treatment. Hence, the strategy affirms the project’s sustainability goals since it was energy efficient as water flows from the rivers to the dams through gravity. The NCT project’s impacts vary according to the area’s communities benefiting from the three rivers are situated. For instance, the findings showed that those living around the project are not affected by flood management but could experience deforestation and landslides due to effects of the dam. Conversely, communities downstream could experience reduced water supply and lowering water tables that could reduce capacity of the boreholes leading to acute water shortage. On the flip side the project could contribute significantly towards flood management. Downstream communities in the Arid and Semi-arid areas face perennial flooding that led to substantial socioeconomic losses including disruption of agricultural production, and destruction of property and life before facing another season of drought. It was evident that limiting flooding, deforestation, and siltation are the primary measures the NCT project stakeholders are focusing on based on the information the feasibility studies generated. Besides, stabilizing water flow to communities downstream was paramount to minimize its adverse socioeconomic impacts on their livelihoods. The national government, ministry of water, sanitation and irrigation and NEMA should institute a policy that will guarantee environmental protection as well as sufficient water for all the surrounding communities.Item Greenhouse Gas Emissions and Environmental Impacts of Energy Use by Selected Tea Factories in Kenya(Kenyatta University, 2023-01-31) Kibet, Joy Jepng'etichTea sector is an important contributor to Kenya's economy since it is a major contributor to foreign exchange via export, which contributes significantly to gross domestic products. An extensive amount of energy is required to produce one kg of tea making tea production and processing energy intensive. Increased energy demand in the tea sector in turn increases the emission of greenhouse gases and environmental impacts arising from the energy use. Despite tea factories having access to renewable sources of energy, non-renewable sources like firewood are still consumed largely. Tea factories don't have enough evidence on which energy type to utilize in order to reduce GHG emissions and environmental impacts and ensure energy sustainability. Research on the comparison of different energy use, emission, and environmental impacts has not yet been done, which is the focus of the study. Therefore, it is imperative to compare different energy sources and their environmental impacts so as to find a sustainable energy source for the tea sector in Kenya, which in this study are fuel wood, solar, briquettes and biogas. The objectives of the research are to assess energy use between 2016 to 2020, determine amount of greenhouse gas emissions, and to compare environmental impacts of energy use by the four tea factories using different energy sources in Kenya. The tea factories involved in the study are Kagwe in Kiambu County, Makomboki Murang'a County, Chemogondany in Kericho County and Kitumbe in Bomet County. The study utilized descriptive- comparative research design to analyse the survey interviews data and records obtained from the tea factories. The Intergovernmental Panel on Climate Change emission factor is used to calculate the total emissions of each type of energy used for 5 years. Life cycle assessment using simapro software is used to assess the specific compound causing the emission. Purposive sampling was used in selecting the four tea factories and the key informants. Primary data was derived from interviewing key informants. Secondary data was obtained from the tea factories records and reports. Life cycle assessment was done using Simapro 7.3 as the software tool and Eco-indicator 99 as the assessment method. The finding reveals that there is an increased demand of energy in tea factories in Kenya as shown by a 5-year energy consumption trend; which implies that more emissions and environmental impacts is experienced. The greenhouse gas emission from wood consumption for a period of 5 years is 0.104771 scores of total environmental load while solar energy has a total score of 2.77E-07 scores. This implies that wood energy produces more emissions compared to electricity, solar, and briquettes; with solar having the least emissions of all. Life cycle assessment model shows that wood has more impact compared to other three types of energy assessed with a total value of 13996.23 score impact categories. The government should give clear guidelines on the regulation on the type of energy to be used in the tea factories. Additionally, sensitization by the respective government bodies on the use of the by products from the tea processing should be a considered.Item Determinants of Integrated Pest Management Adoption among Large-Scale Farmers in Uasin Gishu County, Kenya(Kenyatta University, 2024-11) Cherotich, NellyIntegrated pest management (IPM) is a long-term management practice involving cultural, biological, and physical methods. Chemical control is only applied where other techniques are ineffective and pesticides that only kill the target organisms are selected to minimize environmental pollution. This research examines the different IPM practices adopted,the determinants of IPM adoption, and information dissemination channels for the adoption of these practices among large-scale farmers in Soy sub-county. The study surveyed a total of 155 large-scale farmers from 13 locations in Soy sub-county. The study employed a survey research design and collected data through household questionnaires, interview with the extension officers, and a focus group discussion schedule with the farmers association. Descriptive statistics was used to analyze data where tables, graphs, and pie charts were used in presenting the quantitative data. Data from the focus group discussion schedule and interview schedule were analyzed using qualitative content analysis. The findings showed that natural IPM methods adopted were cultural, physical, and biological practices. The chemical methods adopted were herbicides, insecticides, and fertilizers. Education level, age, main occupation, household income, farmer field day participation, machinery ownership, farm size, and pest and weed resurgence were the main determinants for IPM adoption among the respondents. The respondents obtained information on IPM practices through farmer-to-farmer training, field exhibitions, farmer field days, television, radio, and extension officers. As a result, there was inadequate information on complex practices of natural IPM practices as they required proper training hence the main dependence on chemical control methods due to their quick and guaranteed results in crop yields.Item Uptake of Community Led Total Sanitation among Residents of Isiolo County, Kenya(Kenyatta University, 2024-08) Osman, Mahad BagajaThe study aims to assess the uptake of Community Led Total Sanitation among residents of Isiolo County, Kenya, focusing on individual factors, latrine ownership and use, and institutional factors associated with uptake. Despite the global call for universal access to sanitation and hygiene, about 673 million people still defecate in the open, despite the Kenyan government's adoption of this program. The cross-sectional descriptive study design, using both quantitative and qualitative data collection methods, aims to provide a comprehensive understanding of the issue. The sample size comprised of 373 household heads systematically picked at an interval of 8 from villages in selected Wards of Ngare Mara and Oldonyiro wards. Isiolo County was purposively selected since it is among the top ten counties practicing open defecation. Key informants comprising of healthcare workers, religious leaders and chiefs/opinion leader were also interviewed. Isiolo sub-county was randomly selected using folded pieces of paper while Ngare Mara and Oldonyiro Wards were purposively chosen as they recorded the highest prevalence of diarrheal diseases. The researcher sought all required approvals from relevant institutions and obtained informed consent from participants. Quantitative data was collected using structured questionnaires from household heads while qualitative data was collected using Key Informant Interview schedules from opinion leaders. Quantitative data was analyzed using Statistical Package for Social Sciences version 22.0. Qualitative data was triangulated with quantitative results as direct quotes or narrations as presented by the key informants. Chi-Square tests were done at 95% confidence interval with a 0.05 margin of error of 0.05 to calculate inferential statistics. The study results revealed that the rate of community led total sanitation in Isiolo County was 31.9%. The majority (54.3%) of responded owned a latrine with only 42.1% showing evidence of use. Majority of individual factors such as awareness of negative effects of open defecation (P=0.011), willingness to use a latrine (P=0.024), ability to construct and maintain a pit-latrine (P=0.001) and decision makers of pit-latrine construction (P=0.001) influenced community led total sanitation uptake. Most (53.5%) of the households owned a pit latrine with owning a pit-latrine (P=0.001), place of defecation (P=0.003), washing hands after visiting a pit-latrine (P=0.001) and disposal of child excreta (P=0.023) significantly associated with community led total sanitation uptake. Most institutional factors such as provision of incentives for pit-latrine ownership (P=0.013), source of information on health issues (P=0.001), community involvement in planning their health activities (P=0.041) and invitation for meetings on sanitation (P=0.038) significantly influenced uptake of community led total sanitation. The study concludes that the rate of community led total sanitation in Isiolo County was low. In fact, only three in every ten households in the county uptake community led total sanitation. The results will inform policy makers, academic researchers and other stakeholders to craft interventions for action to improve sanitation coverage by implementing community led total sanitation. This will help reduce open defecation rates and decrease diarrheal diseases thus contributing positively to the achievement of the Sustainable Development Goal number six by the year 2030.Item Dynamics of Ecohydrology, Governance, and Community Livelihoods of Migori River Watershed, Kenya(Kenyatta University, 2023-06) Balaka, StephenThis study investigated the dynamics of ecohydrological processes, watershed governance, and livelihood systems of Migori River watershed. The objectives of the study were to; examine the institutional arrangements in the Migori River watershed management and their influence on the nature and level of coordination among the actors, evaluate the impacts of land use and land cover (LULC) changes on the trends of stream flow and sediment yields in Migori River watershed from 1980 – 2020, assess the spatio-seasonal variations of water quality parameters of Migori River and associated household health risk implications in Migori River watershed, and assess the level of sustainability of community livelihoods in the Migori River watershed and its associated vulnerability to climate change impacts. The study adopted a mixed-method approach comprising case and cross-sectional study designs which enabled the collection of both qualitative and quantitative data from different sources. Governance assessment was based on semi-structured interview data qualitatively analyzed through content analysis in ATLAS.ti software. Simulation of hydrological changes due to LULC changes was performed using the Soil and Water Assessment Tool (SWAT) model embedded in QGIS, with analysis of LULC patterns from remote sensing data conducted based on maximum likelihood classifier algorithm. In assessing the water quality trends along with potential health risks, 18 physico-chemical and bacteriological variables were sampled and analyzed monthly for two seasons from six stations using standard procedures, and a health risk survey conducted with 90 households. ANOVA and T-test were used to test for the significant spatial and seasonal variations, respectively; whereas the overall water quality status was analyzed using the CCME water quality index (CCME-WQI). The community livelihoods‘ sustainability level in the watershed and its associated vulnerability to climate change impacts were analyzed using the Livelihood Sustainability Index (LSI) and Livelihood Vulnerability Index (LVI-IPCC), respectively, based on 318 households‘ survey data. The results on the structure and roles of institutions at various levels revealed adequate representation of the river basin management actors within the watershed; but the associations among these actors are weak due to conflicting and overlapping mandates, and gaps in the coordination processes. The watershed has undergone a substantial transformation between 1980 and 2020, with a considerable decline in shrub lands by 40.63%, grasslands by 84.86%, forests by 52.90%, water by 82.03%, and wetlands by 38.44%; whereas cultivated land, bare land and built-up areas have expanded over the same period by 34.25%, 132.28% and 461.20%, respectively. These LULC changes, majorly driven by population pressure and poverty, have contributed to the decline of actual evapotranspiration by 2.83%, potential evapotranspiration by 5.38%, and groundwater flow by 19.06%; and an increase in surface runoff by 32.57%, water yield by 4.82% and sediment by 84.58%. Water quality variables showed significant seasonal variability but no significant spatial differences at p < 0.05; with integrated analysis showing the river is polluted and potentially hazardous for human usage due to high bacteriological levels. The LSI and LVI-IPCC respectively categorized the watershed households as moderately sustainable and moderately vulnerable to climate risks, with no significant differences across the watershed zones (p < 0.05). The study concludes that the changes in land use practices and climate variability has negatively impacted hydrologic flows and has implications for watershed community livelihoods, which the existing governance framework may not effectively manage due to flaws in the institutional structure undermining coordination of stakeholders. The study recommends interventions in the institutional design of the governance system; and implementation of suitable land use zoning, multifaceted pollution control measures and rural development initiatives for enhancing household‘s adaptive capacity to climate change.Item Determinants of Spatial Distribution of Trees Outside Forests along Urban-Rural Gradients: A Review(Sustinere: Journal of Environment and Sustainability, 2024-05) Kariuki, Dorcas Wambui; Letema, Sammy C.; Opinde, Godwin O.Urbanization can create uncertainty for biodiversity.Understanding the spatial distribution of trees along urban-rural gradients is crucial for sustainable land management and the conservation of biological diversity. However, limited information is available on the factors influencing the distribution of trees outside forests along urban-rural transition gradients. This paper uses the Preferred Reporting items for Systematic Reviews and Meta-Analyses (PRISMA) to review how distance from urban centers, land use types, socio-economic disparities,and community attitudes and perceptions impact the spatial distribution of trees outside forests along urban-rural gradients. The review indicates that the species composition, diversity, density, and spatial arrangement of trees outside forests vary along the urban-rural gradient. The most commonly cited factors influencing this distribution are respondents' attitudes and perceptions of trees, socio-economic factors, and land use variations. Distance from the urban center was the least citedfactor. However, there is significant variation in how different factors impact this distribution from study to study. Therefore, further research is needed to better understand the factors driving changes in the diversity of trees outside forests in various urban-rural contexts and to determine whether variations exist across different settings.Item Desert Locust (Schistocerca gregaria) Invasion Risk and Vegetation Damage in a Key Upsurge Area(MDPI, 2023-03) Mongare, Raphael; Abdel-Rahman, Elfatih M.; Mudereri, Bester Tawona; Kimathi, Emily; Onywere, Simon; Tonnang, Henri E. Z.In the recent past, the Horn of Africa witnessed an upsurge in the desert locust (Schistocerca gregaria) invasion. This has raised major concerns over the massive food insecurity, socioeconomic impacts, and livelihood losses caused by these recurring invasions. This study determined the potential vegetation damage due to desert locusts (DLs) and predicted the suitable habitat at high risk of invasion by the DLs using current and future climate change scenarios in Kenya. The normalized difference vegetation index (NDVI) for the period 2018–2020 was computed using multi-date Sentinel- 2 imagery in the Google Earth Engine platform. This was performed to assess the vegetation changes that occurred between May and July of the year 2020 when northern Kenya was the hotspot of the DL upsurge. The maximum entropy (MaxEnt) algorithm was used together with 646 DL occurrence records and six bioclimatic variables to predict DL habitat suitability. The current (2020) and two future climatic scenarios for the shared socioeconomic pathways SSP2-4.5 and SSP5-8.5 from the model for interdisciplinary research on climate (MIROC6) were utilized to predict the future potential distribution of DLs for the year 2030 (average for 2021–2040). Using Turkana County as a case, the NDVI analysis indicated the highest vegetation damage between May and July 2020. The MaxEnt model produced an area under the curve (AUC) value of 0.87 and a true skill statistic (TSS) of 0.61, while temperature seasonality (Bio4), mean diurnal range (Bio2), and precipitation of the warmest quarter (Bio18) were the most important bioclimatic variables in predicting the DL invasion suitability. Further analysis demonstrated that currently 27% of the total area in Turkana County is highly suitable for DL invasion, and the habitat coverage is predicted to potentially decrease to 20% in the future using the worst-case climate change scenario (SSP5-8.5). These results have demonstrated the potential of remotely sensed data to pinpoint the magnitude and location of vegetation damage caused by the DLs and the potential future risk of invasion in the region due to the available favorable vegetational and climatic conditions. This study provides a scalable approach as well as baseline information useful for surveillancItem Settlement Schemes and Their Implication on Eastern Mau Watershed, Nakuru County, Kenya(Kenyatta University, 2022) Cherotich, Fredah; Sammy LetemaSettlement schemes are aimed at settling landless people and those displaced by disasters to support socio-economic and environmental development of a country. Eastern Mau Forest Reserve is an important watershed that has settlement schemes established, which has led to encroachments and degradation of the watershed. This study, therefore, assessed the implications of human settlements on Eastern Mau watershed by examining the trends in land use/cover change, settlement schemes and river flows for four decades, from 1979 to 2020. Eastern Mau Forest Reserve is a major water tower therefore the large tracts of land that have been cleared coupled with the settlements in it is a worrying trend. It is essential to develop an approach that will aid in assessing land use land cover changes and effects on hydrological components at catchment level to aid in planning, use and management of resources. Primary data was collected from key informant interviews based on purposive sampling. Secondary data was derived from Landsat satellite images over a 10-year period and analysed using Maximum Likelihood Function from ArcGIS. Data on river flows from River Njoro was obtained from Water Resources Authority Office in Nakuru County for 1979-2020. Rainfall data for 1979-2020 was obtained from Kenya Meteorological Station, Nakuru Town. Time series analysis is used to understand the trend in river flows over time while Pearson correlation is used to determine relationship between farmlands and river flows. The results indicate a sharp decline in forest cover by 42.7% and an increase in farmlands by 41%. Dense vegetation and farmlands have an inverse relationship as an increase in farmlands lead to a decrease in forest cover and vice versa. People have settled beyond the established settlement schemes leading to encroachment and drying up of some rivers. There is also an increase in rainfall and river flows over the years, with monthly river flows increasing in peak flows and declining during low seasons. There is a positive correlation between farmlands and river flows between 1989 and 2020. Settlements affect land cover that in turn affects forests and impacts capacity of land to absorb rainfall water, which leads to higher runoff and subsequently higher flows. There is need for regeneration of encroached areas and defining boundary of Eastern Mau to allow initiatives and interventions that help with sustainable management of the watershed area.