MST-Department of Environmental Science

Permanent URI for this community

https://repository.ku.ac.ke/handle/123456789/256

Browse

Now showing 1 - 20 of 231

Abundance and potential use of grevillea robusta in the wood carving industry. a case of Embu district, Kenya
(2012-03-30) Wamboi, Jane Franciscah; Aloo, T. C.; Ndungu, A.
Closed canopy forests cover about 2% of Kenya's total land area (Crafter, Awimbo and Broekhoven, 1997) with an annual deforestation rate of 54km2 between 1980 and 1990, but rank high as one of the country's most important national assets. Presently, there is intense pressure on forests due to increased demand for land for alternative uses like farming and high demand for tree products in the growing economy. Today, the wood resource is in a critical state of overexploitation, particularly with respect to targeted tree species in the wood carving industry (Choge, 2000). This study was carried out between September, 2000 and January 2002 to determine the abundance and potential use of Grevillea robusta in the wood carving industry. The main aim of the study was to investigate the potential contribution of Grevillea robusta towards alleviating the pressure on indigenous species in the wood carving industry. The specific objectives were to determine the volume, density and distribution of G. robusta in Embu district; to find out current and potential uses of G. robusta by farmers in Embu and to determine customer and consumer preference of wood used in carvings and the volume of G. robusta required by the carvers annually. Seven Agroecological zones (AEZ): Upper Midland 1 (UM1), Upper Midland 2 (UM2), Upper Midland 3 (UM3), Upper Midland 4 (UM4), Lower Highlands (LH), Lower Midland (LM3), Lower Midland 4 (LM4) of Embu District, where, both indigenous and exotic tree species are grown were used for this study. Both primary and secondary sources of data were used. A sample of two hundred and ten households in seven agroecological zones was drawn using random sampling technique. Data was collected by means of questionnaires, checklists and observation schedules. Tree heights and diameters were taken using a suunto hypsometer and a diameter tape respectively. Data was analyzed using descriptive and inferential statistics. Carvers and traders in the wood carving industry were also interviewed using checklists. The results show that the highest number of Grevillea trees are found in UM3 this being 22% of the total number of Grevillea in the seven agroecological zones. The results further indicated that the forest department nurseries supplied the respondents with 24.3% of Grevillea seedlings. It was further found that 19% of farmers are not willing to sell their trees since they are used for soil conservation and household needs such as firewood, timber, construction and fodder. The farmers also have alternative sources of income such as the livestock. The study findings revealed a problem of lack of awareness of the option of using Grevillea robusta as a wood carving species among most farmers and carvers. The rate of cutting of the trees per month varied among the respondents. Those who cut between 1-5 trees were 67%. This may have been as a result the ban on logging in the national forests and therefore middlemen were buying Grevillea for the timber industry. It is clear from the study that Grevillea has a medium potential as an alternative wood carving species and that carving of Grevillea wood is currently minimal. From the study not even one trader sold carvings made from this tree species. The study recommends moving the carving sites close to the farmers as this may encourage carvers to use Grevillea and also reduce on the transportation cost of the logs. This may be applicable when the carvers have a specific order on carvings made from Grevillae. There is need to create awareness among buyers on the need to buy carvings made from 'good wood' species such as Grevillea so as to conserve forests for the sake of biodiversity for future generations. Such interventions will enable the government to develop workable farm forestry policies and hence achieve the goal of protecting and conserving the natural indigenous hard woods.
Adaptation to Climate Variability by Smallholder Dairy Farmers in Nyandarua County, Kenya
(Kenyatta University, 2018) Changara, Abraham Odari
Dairy farming constitutes a significant source for livelihood to a majority of households allover the world, including Kenya. Climate variability impacts negatively on dairy farming. The smallholder dairy farmers have not appropriately domesticated the necessary adaptation mechanisms for resilience against climate variability in Nyandarua County. This study assessed the strategies and practices adopted by farmers in order to cope with climate variability and its effects on smallholder dairy farming in Nyandarua county. The aim of the study was to assess climate variability, its relationship with dairy farming and to document coping strategies for resilience against climate variability by the smallholder dairy farmers of Nyandarua County. The study adopted an integrated conceptual framework approach (combined socio-economic and biophysical) in which rainfall and temperature is seen to impact dairy systems and farmers‟ coping capacity. Data on climate variables of temperature and rainfall was obtained from the Kenya Meteorological Department(KMD), while data on dairy production was from the Kenya Dairy Board (KDB) that has the mandate of regulating, promoting and developing the dairy industry in Kenya. Primary data was collected from households using semistructured questionnairers, field observations and key informant interviews. The data collected was analyzed using Statistical Package for Social Sciences (SPSS) and excel spreadsheet, to generate frequencies, tables, pie charts and graphs. The findings established a significant relationship between milk production and climate variability, (P=0.047) for temperature and precipitation. Further analysis shows a positive correlation of 0.784 for milk production and climate variability. The adjusted R² Coefficient of determination was found to be 0.58, implying that 58% variation in milk production could be explained by climate variability. A unit positive change in temperature would result in -0.109 change in milk production while a unit change in precipitation would have +0.398 increases in milk production. Periods with high temperature resulted in low production of milk while high precipitation gave rise to increase in milk production. Some of the strategies adopted for coping with climate variability included; the provison of adequate feeds, storage of hay and silage, rainwater harvesting, construction of cattle shades to moderate adverse weather conditions, early milking of the animals at mid-day before the animals experience high humidity and temperature stress. Majority of the respondents had access to credit during extreme climate condition as a coping strategy. The study advocates for development of irrigation infrastructure in the region so as to make water easily accessible and also augment the water harvested during the seasonal rainfall period in the County. County Meteorological Services delivery should be strengthened and enhanced so that climate forecast products may be disseminated to farmers on regular and timely basis
Adoption of Biogas Technology and Its Contribution to Livelihoods and Forest Conservation in Abogeta Division, Meru County, Kenya
(Kenyatta University, 2018) Mwirigi, Erick K.
Fuelwood is the predominant energy source for cooking in rural households of Abogeta division in Meru County. Previously most wood was sourced from Mt. Kenya forest reserve. However, since enactment of a legislation prohibiting cutting of trees in the national forest reserves in the year 2005 by the Government of Kenya, there has been a serious shortage of wood fuel in Abogeta hence need for an alternative energy source. Biogas technology can greatly impact peoples’ livelihoods particularly in rural areas through creation of local jobs, improving agricultural production, financial diversification and provision of clean source of cooking energy. The main objective of the study was to determine the factors influencing adoption of biogas technology in rural households of Abogeta division in Meru County and assess how rapid adoption could support local livelihoods and conserve forest. Three objectives guided the study; (1) to determine factors influencing adoption of biogas technology in Abogeta division, (2) to determine the contribution of biogas to financial and time savings and how these savings are important to households in improving their lives and (3) to determine how adoption of biogas technology reduces wood fuel demand and contribute to tree cover enhancement in Abogeta division. To achieve these objectives, 230 dairy farming households were sampled. Biogas adopters were purposively selected from 68 households that had already installed the systems while 163 non-adopters were randomly selected from the study population based on administrative boundaries. Primary data were derived from field surveys using questionnaires, interviews and focus group discussions. Analysis of the data was done by use of Statistical Package for Social Sciences. Descriptive statistics, tests of significance (t-tests) at 0.05 confidence level as well as multiple linear regression were used to establish relationships between variables. The study revealed that household income and education level significantly influenced the technology uptake. On the impacts of biogas technology on livelihoods, significant financial savings were realized with an average adopter household saving up to about KSh 3,000 per month upon shifting to biogas energy. Adopter households also used 3 hours less per week in firewood gathering as compared to non-adopter households. Both financial and time savings were used to improve household livelihoods by engaging in extra income generating activities and in social activities. There was also a significant decrease in wood fuel consumption with adoption of biogas. Approximately 150 Kg/household/month and 30 Kg/household/month of firewood and charcoal respectively were saved every month by adopter households. Therefore, if all the 12,100 households in the study area adopted biogas, 180 tonnes of firewood and 32 tonnes of charcoal would be saved every month which would in turn help in conserving murama (Combretum molle) and mwiria (Prunus africana) tree species which are the most preferred species for wood fuel in the study area. In conclusion, the potential of biogas technology in improving people’s livelihoods and conserving forest was found to be significant. However, household income education level and lack of affordable credit facility were found to be the key barriers to rapid adoption.
Adoption of Climate-Smart Technologies and Their Effect on Income among Agro-Pastoralists in Marsabit County, Kenya
(kenyatta university, 2023) Gudere, Ann Ngauri; Evelyn Wemali; Ezekiel Ndunda
The world is facing variable weather events and gradual climatic change and Kenya’s arid lands where pastoralism is a viable livelihood option are not exceptional. Marsabit County, inhabited by diverse pastoral and agro-pastoral groups, faces extreme climatic events that affect local livelihoods. Despite the government and development organizations disseminating climate smart technologies and practices, the communities still rely on emergency food aid which is unsustainable. Given climate-induced uncertainties, climate-smart technologies may offer viable adaptation options for agro-pastoralism based economies that enhances resilience, increases productivity and reduces greenhouse gases. This study was conceptualized in line with the action theory of adaptation to climate change leading to four objectives; analyze temperature and rainfall trends in Saku Sub-County (1980-2020), identify livestock-crop smart technologies adapted, analyze determinants of climate-smart technologies adoption and assess the impact of adoption of smart technologies on household income. The research design was a survey with a sample size of 373 households in Karare, Marsabit Central (Dakabaricha) and Sagante/Jaldesa wards. Stratified sampling was used in selecting the study sites while systematic random sampling was applied in selecting the households of the agro-pastoralists. The data was collected using questionnaires installed in Kobocollect that were administered through face-to-face interviews with agro-pastoralists, interview schedules administered to 10 key informants and focus group discussions held with 6 groups. Climate data on temperature and rainfall trends were analyzed with Mann Kendall and Sen's slopes, descriptive statistics were generated for the socio-demographic characteristics of the sampled households while determinants were assessed through multivariate probit regression and propensity matching score on the impact of climate smart technologies adoption on income. Decreasing rainfall and increasing maximum temperature trends were significantly in August and September while the minimum temperature trend was significantly increasing in all the months. Agro-pastoralists practiced crop and livestock climate smart technologies and the most adopted categories were improved and traditional crop varieties and soil fertility management (92%), followed by water and water use management (85%) while the least used was livestock management (15%). Agro-pastoralists age, household size, gender, education status, marital status, average income per month, access to credit, training, extension services and weather information influenced the adoption, with agro-pastoralists who adopted multiple climate smart technologies showing significantly higher income. The study recommends that agro-pastoralists should have timely access to weather information in order to make important decisions for adoption of climate smart technologies. Governments, research institutions and non-governmental institutions should closely work together in training and providing extension services to agro-pastoralists on livestock and crop husbandry best practices. The governments and development partners to consider socioeconomic and institutional factors when disseminating multiple crop-livestock climate-smart technologies and practices for enhanced income and more resilient communities.
Adoption of Climate-Smart Technologies and their Effect on Income among Agro-Pastoralists in Marsabit County, Kenya
(Kenyatta University, 2023-10) Ngauri, Gudere Ann; Evelyn Wemali; Ezekiel Ndunda
The world is facing variable weather events and gradual climatic change and Kenya’s arid lands where pastoralism is a viable livelihood option are not exceptional. Marsabit County, inhabited by diverse pastoral and agro-pastoral groups, faces extreme climatic events that affect local livelihoods. Despite the government and development organizations disseminating climate smart technologies and practices, the communities still rely on emergency food aid which is unsustainable. Given climate-induced uncertainties, climate-smart technologies may offer viable adaptation options for agro- pastoralism based economies that enhances resilience, increases productivity and reduces greenhouse gases. This study was conceptualized in line with the action theory of adaptation to climate change leading to four objectives; analyze temperature and rainfall trends in Saku Sub-County (1980-2020), identify livestock-crop smart technologies adapted, analyze determinants of climate-smart technologies adoption and assess the impact of adoption of smart technologies on household income. The research design was a survey with a sample size of 373 households in Karare, Marsabit Central (Dakabaricha) and Sagante/Jaldesa wards. Stratified sampling was used in selecting the study sites while systematic random sampling was applied in selecting the households of the agro-pastoralists. The data was collected using questionnaires installed in Kobocollect that were administered through face-to-face interviews with agropastoralists, interview schedules administered to 10 key informants and focus group discussions held with 6 groups. Climate data on temperature and rainfall trends were analyzed with Mann Kendall and Sen's slopes, descriptive statistics were generated for the socio-demographic characteristics of the sampled households while determinants were assessed through multivariate probit regression and propensity matching score on the impact of climate smart technologies adoption on income. Decreasing rainfall and increasing maximum temperature trends were significantly in August and September while the minimum temperature trend was significantly increasing in all the months. Agro-pastoralists practiced crop and livestock climate smart technologies and the most adopted categories were improved and traditional crop varieties and soil fertility management (92%), followed by water and water use management (85%) while the least used was livestock management (15%). Agro-pastoralists age, household size, gender, education status, marital status, average income per month, access to credit, training, extension services and weather information influenced the adoption, with agro-pastoralists who adopted multiple climate smart technologies showing significantly higher income. The study recommends that agro-pastoralists should have timely access to weather information in order to make important decisions for adoption of climate smart technologies. Governments, research institutions and nongovernmental institutions should closely work together in training and providing extension services to agro-pastoralists on livestock and crop husbandry best practices. The governments and development partners to consider socioeconomic and institutional factors when disseminating multiple crop-livestock climate-smart technologies and practices for enhanced income and more resilient communities.
Adoption of energy-conservation technologies by rural households in Kathiani division Machakos district.
(2012-04-04) Karanja, Lydia Njeri
The crisis of declining availability of domestic fuel and its perceived link with environmental degradation continues to influence extensive investment in the design of energy-conserving technologies and the promotion of new forms of forestry management. These initiatives have drawn strength and impetus from the growing awareness of gender issues, along with the recognition that women tend to be affected first and most strongly by fuel shortages. Although numerous programmes have been started in Kenya to increase supply of domestic fuel, namely, planting woodlots, agro forestry, improvement of the efficiency of kilns, and use of energy-saving stoves, fuel shortages continue to be severe especially in arid and semi-arid areas. This study set out to determine factors influencing adoption or non-adoption of energy-conserving technologies in a rural setting of Kathiani Division of Machakos District. Using random sampling, a sample of ninety households was drawn to establish the said factors through the analysis of data collected by means of questionnaires. Interviews were also conducted to gather information from key informants, namely, the Home Economics Extension Officer, and the Rural Afforestation Officer of Kathiani Division. The survey data analyzed using the Statistical Package for Social Sciences (SPSS). This study established that factors such as: age, educational level, income level, family size, time, and occupation influence energy sources used. The findings also showed that adoption of energy-conserving technologies was influenced by age, educational level, occupation, time, income level and distance traveled to energy source in the study area. For instance, respondents from low-income households who cannot afford to buy energy-saving devices tend to use technologies that do not efficiently conserve firewood, compared to those from high-income households who adopted more efficient energy-saving devices, such as the Kuni Mbili, Maendeleo and Kenya Ceramic jikos. From the study findings, it is evident that rural households acknowledge advantages of using energy-saving devices, namely, the conservation of heat (otherwise lost by open-fire), which leads to the reduction of firewood used. However, an equally high number of the respondents used technologies that did not conserve fuel, such as, the Charcoal Metal Jiko and the Traditional three-stone fire. Not only is the adoption of energy-conserving technology low, but also the sustenance of the already adopted technologies is equally low. Non-adoption was attributed to a combination of factors. The study findings revealed a problem of lack of awareness of energy-saving technologies and recommends the need to train more extension workers to create awareness and encourage the adoption of energy-saving devices, through demonstrations, persuasions, workshops and seminars. Also rural households should be assisted to purchase clay-liners for effective construction of Kuni mbili and Maendeleo Jikos. On the issue of energy policy, the study established that if existing policies were properly implemented, then there could emerge opportunities to promote the dissemination of energy-conserving technologies. For instance, the provision of credit facilities for households to construct Kuni Mbili and Maendeleo Jikos and use of demonstration centres to educate rural households on the importance of energy-saving devices. On future research options, there is need to investigate wood production and consumption patterns under a rural scenario and to introduce alternative sources of energy. These include, solar energy in rural areas, which are not connected to national power grid line, biogas for domestic energy and tree-planting programmes for sustainable environmental protection. Such research could enable the government to develop workable renewable energy policies and achieve the goals of sustainable development.
Adoption of energy-efficient woodstoves and contribution to resource conservation in Nakuru County, Kenya
(2012-04-03) Njogu, Paul Kuria
Biomass energy provides 68% of Kenya's national energy requirements and it is expected to remain the main source of energy for the foreseeable future. The current biomass demand in Kenya is estimated at 40.5 million tonnes against a sustainable supply of 16 million tonnes. Many of the rural households use traditional stoves which have low energy efficiency leading to using more woodfuel, increase in indoor air pollution and also putting alot of pressure on the biomass sources. There have been efforts to promote use of woodfuel conservation technologies. This programme has been spearheaded by the ministry of energy, Ministry of agriculture, and many NOOs. There are technologies promoted in Kenya that can reduce the consumption of biomass energy by 80%. They include the improved charcoal stoves (KCJ) which can save upto 50%, the improved fuelwood stoves (e.g Kuni Mbili) which can save upto 50% and the fireless cookers that can save upto 50%. This study was carried out to assess the levels of acquisition and use of these technologies in Lanet Division (Urban area) and Dundori Division (Rural area) both in Nakuru County, determine the social economic factors influencing adoption as well as assess the levels of awareness of weather changes and the need for environmental conservation among the people in the study area. The research study used questionnaires, interview schedule, photography and observation in data collection. Analysis of the data was done by use of SPSS. Data was analyzed by use of; Bar charts, percentages, means and standard deviation, tTest, Pearson and Spearman Correlation test as well as multiple regression analysis. It was found out that the level of adoption of improved charcoal cookstoves (KCJ) was higher in the urban (93%) than rural areas (81 %) while the level of adoption of improved firewood stoves was quite low both in rural (9.18%) and urban (1.08%) areas. Adoption of fireless cookers was also found to be low for both rural (1.53%) and urban (8.06%). Income of the household (r-0.230) and level of education (r-0.232) were positively correlated to acquisition and use of the energy saving technologies. While the numbers of dependants (t value- -3.365), cost of improved fuelwood stoves (t-value 6.658), cost of improved charcoal stoves (t-value -7.161) and the cost of fireless cookers (t-value -11.385) all with a p-value of 0.000 were found as some of the social economic factors influencing adoption of these technologies. The level of awareness on drastic changes in weather was found to be high (90%). There is need for various stakeholders to increase diffusion of quality charcoal cookstoves at an affordable price as well as intensify promotion of firewood improved stoves especially in the rural areas where majority of the people depend on firewood as their main source of fuel. There is also need to invest in the development and promotion of other renewable energy technologies such as biogas and solar energy whose uptake was negligible in the study area.
Adoption status of multi-storey gardens and opportunities for vegetables production in Pumwani division, Nairobi
(2011-08-01) Karimi, W. Julia; Waswa, F.; Abwao, Peter
Pumwani division is one of the areas that have been affected by the high rate of urbanization in Nairobi. Land for agricultural production has greatly reduced posing a threat to food security among the urban poor. The contribution of urban agriculture to food security and nutrition is critical. In the recent past, the government and other stakeholders have enhanced the growth of vegetables by using multi-storey gardens. However the adoption rate among potential users remains low. This research focused on the adoption status of multi-storey gardens in the division with the aim of contributing to scaling-out this technology for increasing vegetable production. A descriptive survey with both quantitative and qualitative aspects was adopted as the research design. Data were gathered using questionnaires, observation and photography from 90 households who live in both formal and informal settlements. Data collected were analyzed using descriptive statistics. The results showed that 80% of the respondents were aware of multi-storey garden farming system but the adoption rate was 60%. This was attributed to the various challenges faced by respondents such as inadequate land size, income and lack of technical skills. It further revealed that those who adopted the technology 65% grew exotic vegetables where 40% used no organic fertilizers. Social factors such as education, age, attitude and customs played a major role in the consumption of the indigenous vegetables in the division. The conclusion drawn from the results of the study was that multi-storey gardens systems were not fully adopted by the community. Most of the farmers grew exotic vegetables and organic fertilizers were not utilized to increase production. Scaling-up and out the multi-storey gardens by planting indigenous vegetables and use of organic fertilizers to increase vegetable production. This would contribute to better health and achieve food security in the division. The researcher recommends that the extension staff on the ground should continue to educate the community on the nutritive importance of indigenous vegetable and need to increase production and consumption. Further they should sensitize and train the community on the available resources that can be utilized to make organic fertilizers locally. City by-laws that do not allow farming should be revised to incorporate urban farming as a mean of improving food security in the urban setting. There is need for further study to assess the effectiveness of extension services in improving food security in the division. More should be done on vegetable value addition to ensure continuous supply throughout the year.
Agrobacterium Tumefaciens-mediated transformation of three sweet potato varieties with xerophyta viscosa Peroxiredoxin 2 gene conferring drought stress tolerance
(2011-11-11) Kamwendo, Phillip Mike; Machuka, Jesse; Kwapata, M.
Sweet potato [Ipomoea batatas (L) Lam] is an important food crop and belongs to the family Convolvulaceae. It is a creeping herbaceous perennial vine that is cultivated as an annual crop in the world. Sweet potato is ranked fourth in terms of importance as staple food mostly in the developing world. Countries in Eastern and Southern Africa account for 76% of sweet potato production in Africa. Drought is one of the major abiotic constraints to production of many arable crops with yield losses estimated at 20% although values as high as 100% have been documented under severe conditions resulting into total crop failure. Although several strategies such as conventional breeding, crop introduction, hybridization have been employed in the past to improve drought tolerance, these efforts need to be complemented. Biotechnology offers alternative tools to the development of drought tolerant cultivars via techniques such as genetic engineering. In this study, three test cultivars of sweet potato namely KSP 36, PIPI and Zambezi were regenerated and transformed for drought tolerance via Agrobacterium tumefaciensmediated transformation system using a drought tolerant Xerophyta viscosa peroxiredoxin 2 gene (XvPrx2) isolated from "the resurrection" plant Xerophyta viscosa. The three cultivars were subjected to transformation experiments where Agrobacterium strain EHA101 bearing a standard plasmid was used to infect the transgene into the selected leaf and stem explants in a factorial design. It was established that any time interval from 30 to 60 minutes is sufficient for infection as there were no significant differences (p:0.15) in infection time regimes. Response to Agrobacterium infection, transformation and regeneration was genotype dependent. A total of 10 plantlets were regenerated from over 300 calli used giving regeneration frequencies (RF) of 0.02 for KSP 36, 0.04 for both Zambezi and PIPI. The survival rate of calli on selection was used to calculate the transformation frequencies (TF) which varied significantly (p:_0.001) among the three cultivars as follows KSP36 (0.26), PIPI (0.66) and Zambezi (0.75). Using 0.25mg/L zeatin and lmg/L Indole-3-acetic acid (IAA) only promoted root formation. but when kinetin (2mg/L) and IAA (l mg/L) were used shoot formation was promoted. Leaf explants recorded 87% calli formation whereas stems recorded less than 20%. There were significant differences in cultivar response to regeneration and transformation at p:_0.001 with Zambezi giving the best response. Seven putative transformants from Zambezi cultivar were identified to have been transformed through PCR giving a transformation frequency of 3.3% and transformation efficiency of 2.67%.
Analysis of emission profiles from charcoal produced from different tree species by different pyrolysis methods.
(2015-05) Shikorire, T. J.; Ng’ang’a, M. M.; Kirubi, G.
Charcoal is a major form of biomass fuel for approximately 80% of the Kenyan population. However, the use of charcoal is associated with indoor air pollution where charcoal users are continually exposed to compounds of incomplete combustion which are known to have detrimental effects to human health. This study analyzed the emission profiles of different types of domestically used charcoal produced by different pyrolysis methods. Charcoal samples from three tree species Acacia polyacantha, Acacia xanthophloea and Eucalyptus grandis, produced by both efficient and traditional pyrolysis methods were collected from charcoal producers in Thika, Machakos and Kitengela. The volatiles were collected using a fabricated chimney placed on clay cook-stove such that smoke was vented to a glass canula where it was condensed. Extracted volatiles were then analyzed by gas chromatography-linked mass spectrometry (GC-MS). A total of 22 PAHs were identified together with other groups of compounds that included ketones, aldehydes, phenols, alkanes, alkenes, carboxylic acids, phthalate, esters, and alcohols. The major compounds found in the smoke extracts with known health effects included naphthalene (3), 1-methylnaphthalene (14), 2-methylnaphthalene (5), fluorene (6), phenanthrene (9), anthracene (11), 1-methyl-phenanthrene (14), fluoroanthene (10), benzo(a)anthracene (12) and chrysene (13).There were significant differences (P˂0.05) in the concentrations of fluorine, naphthalene and pyrene emitted from A. polyacantha and A. xanthophlea prepared by traditional pyrolysis. From A. polyacantha concentrations were naphthalene (110.00μg/g), fluorine (72.00μg/g) and pyrene (60.00μg/g) while from A. xanthophlea, concentrations were naphthalene (140.42μg/g), Fluorene (97.35μg/g) and pyrene (71.82μg/g). The volatile emissions from charcoal prepared by traditional pyrolysis had higher concentration of PAHs relative to the accepted levels of 0.1 - 0.2mg/m3. Charcoal prepared by traditional pyrolysis emitted the highest number of PAHs at 6.25mg/m3 while those prepared by efficient pyrolysis produced the lowest concentration at 0.73mg/m3 both from A. xanthophloea. Therefore, there is need to use efficient pyrolysis methods of charcoal production. This will ensure the production of charcoal with low volatile content that are less harmful to the end users.
Analysis of spatial variation of soil fertility gradients in Vihiga and Siaya districts of Western Kenya using geostatistical techniques
(2011-12-15) Okeyo, J.M.; Wamicha, W. N.; Shisanya, C.A.
In western Kenya, several soil fertility management technologies have been developed in specific benchmark areas and then recommended to the rest of the farmers. Adoption of such technologies has been minimal at best, and, one of the reasons given for this low rate of adoption is that they did not take into consideration the existing spatial variations in biophysical and socio-economic conditions within which the local smallholder farmers operate. Against this background, a study was carried out to quantify the variability of soil fertility at different spatial scales and formulate domains for better targeting of soil fertility management recommendations. Farms were selected using a hierarchical Y-frame sampling design and in each farm information on the main biophysical factors collected. Field measurements, observations and sampling were used to collect data on the biophysical conditions, while participatory rural appraisal (PRA) was used to collect socio-economic data. All fields in each farm were characterised and top soil samples collected at a depth of 020 cm. All the sample collection points were georeferenced using a GPS system. Exploratory data analysis techniques were used to assess the effects of biophysical and socio-economic parameters on soil fertility. Geostatistical techniques of semivariography and kriging were used to explore the spatial structure of soil fertility gradients. Mixed effects modelling was used to confirm relationships, while accounting for spatial correlation structures, and understanding the variance of predicted soil organic C at different spatial scales. Predicted soil organic C was found to be spatially correlated and the spatial structure was modelled using experimental semivariograms fitted with spherical, exponential and ratio quadratic models. At the Y-level, using the exponential semivariogram model, spatial structures ranged from weak in Y3 (nugget/sill ratio > 0.75), moderate in Y2, Y5, Y7, Y8 and Y9 (nugget/sill ratio 0.25 < r < 0.75) to strong in Y 1 and Y4 (nugget/sill ratio < 0.25). On average all the three variogram models gave a nugget/sill ratio of between 0.5-0.6 indicating moderate spatial correlation. The maximum range at which this spatial structure can be reliably predicted is up to 60 m beyond which correlation errors increase significantly. All the three model variogram estimates had high nugget variances which imply that the micro-scale variation (i.e. variation below the minimum sampling interval) was large. Analysis of the estimated variance components showed that the field (residual) effect accounted for the greatest percentage (62.5%) of the variation associated with random effects. After accounting for spatial variability all the other measured parameters (fixed effects) failed to explain the large local variability, thus, posing a challenge to making soil fertility management recommendations. Future soil fertility management strategies in western Kenya should target at explaining the large spatial variability of soil fertility within the smallholder farms.
Analysis of water use and trade offs amongst crop and livestock needs in Kalacha settlement, Marsabit district, kenya
(2011-10-31) Sikunyi, Timothy M.
The introduction of irrigation into a pastoral system creates new water demands. These new water demands change the water balance. This study in Kalacha settlement of Marsabit District, analyzed whether the available water was sufficient for both livestock and crop requirements and what tradeoffs options the people had in the usage of a fixed supply of water. Water quality was measured by standard laboratory practices, while flow rate was measured with a flat plate weir. Crop water requirements were calculated from evaporation data. Animal water requirements were calculated as (a) that based on maximum stocking density (b) the stock dependant on forage produced by irrigated crops and (c)those counted by past aerial surveys. Simulation and optimization modeling methods were used with respect of either crop or livestock to provide nutritional needs of residents and establishment of tradeoffs in water use. Results of the study indicated that water supply was 795,00011tres per day (L/D), with a human demand of 28,700, wildlife; 26,475, livestock; 7 to 552,225 L/D while the crop demand; 95,040 to 319,680 L/D. The water balance ranged from negative 259,505 to positive 644,778 L/D. Simulations also indicated that requisite area to achieve community's energy needs (39ha) was higher than that topographically available (7.2). Additionally, that scheduling of irrigation was inadequate due to varying soil infiltration capacity (1.066 to 1.5 nun/min). High energy crops were of generally long growth- periods thereby competing with livestock. Short growing period plants provided livestock with an opportunity window as a trade off, while long growth period plants and intensification reduced it. Further, plants with both high biomass yield for livestock and human energy needs were inefficient water users and were unable to satisfy community's energy requirements despite intensification. Crops however, produced more nutritional energy on weight basis of water consumed. Livestock simulation indicated that 537 goats were necessary for milk production to meet the community energy requirements, while 103 cattle were required for meat production. Whereas the numbers of shoat were within the aerial survey counts, the number of cattle was too close to aerial counts (180) implying use of cattle meat is unsustainable. Sheep however, were the most efficient users of water for each weight gained (98.05kg/m3) followed by camel (17.7kg/m3), goat (42.575kg/m3) and cattle (11.327kg/m3), in that order. For each lactating animal, camels produce more milk (0.11 to 0.46kg/kg), followed by shoats (0.025 to 0.2075kg/kg /kg) then cattle, Shoats have the lowest water capital cost for milk production (81 to 22 3kg), then camel (711 to 5438kg) and cattle(1188 to 1998kg)in that order. In conclusion optimal range stocking resulted in a water deficit. Surplus occurred in scenario (b) and (c). Also, that the water was generally unsuitable for use by irrigation (332.61 mg/l Cl-) livestock (S042-_) and humans (S042-, K+). By cultivating salt tolerant crop and another well, irrigation has some prospect. Despite irrigation's greater energy production, pastoralism performs better than irrigation in the dry lands. A holistic policy is requisite for negotiations and trade offs between competitors, for the scarce water.
Anthropogenic Effects on the Water Quality and Quantity of Ruiru River in Kiambu County, Kenya
(Kenyatta University, 2023-04) Nyasimi, John Ondieki; Esther Kitur; Gladys Gathuru
Abstract
An Appraisal of solid waste management in small towns in Kenya: Acase study of Othaya Town, Nyeri District
(2012-04-11) Thuo, Joseph Kennedy; Agwata, J. F.
The purpose of the study was to investigate the management of solid waste in Othaya town, Nyeri District. The study focused on the nature and quantities of wastes, the existing management capability, pollution and community participation in waste management in the town. It was based on the existing solid waste management system and how the system can be improved for effective waste management system and how the system can be improved for effective waste management in the town. A multiplist methodology was used as the research strategy and the one specifically chosen for this study was modified participatory Rapid Appraisal (PRA). The technique was chosen as it produces similar or comparable results as other methods. Analysis of data was done using descriptive statistics, which included calculation of means, ranges and percentages. Correlation coefficients were also calculated to show relationship between various waste management variables. The findings show a picture of a town in transition in relation to provision of waste management services. The Council, however, has made a good attempt, but the situation is still wanting with most affected areas being the collection, disposal of wastes and community participation. Conclusions of this study call for re-examination of the current waste management system to make it more effective. It is recommended that the entire waste management system be re-organized particularly with regard to waste storage and collection. The Council should also indicated clearly the role of the community in waste management.
Arable farming practices and their implication on water quality in East Bukhayo, Busia district
(2012-05-03) Mwangi, Wilberforce Wangalwa
Arable farming practices such as use of inorganic fertilizers, planting poor cover crops, row planting, cultivation of wetlands and riverine areas and lack of soil conserving farming have been associated with poor stream water quality found in catchment areas where they are practiced. Increase of these practices in East Bukhayo prompted the following question, which this study sought to answer: Do arable farming practices have significant implications on stream water quality? Ten streams with sources and confluences in East Bukhayo Location of Busia District were sampled. Water samples collected from the source, middle and confluence of each stream, twice in the wet and dry seasons, were analyzed for the concentrations of phosphate-phosphorus, nitrate-nitrogen and suspended sediments. An interview schedule was used to interview farmers, while an observation checklist was used to record farming practices and aspects of water quality observed by the researcher. Relationships between practices and aspects of water quality were determined using correlation coefficients, while differences between farming practices and aspects of water quality were determined using Chi-Squared. Descriptive statistics, i.e. averages and percentages were also used to analyze the data. The findings of the study indicated that although no strong relationship exists between use of inorganic fertilizer use and nutrient concentration in streams, there is a strong relationship between inorganic fertilizer use and eutrophication. Nutrient concentrations were found to be generally lowered than the levels recommended by the World Health Organization (WHO). Stream portions in cultivated wetlands and riverine areas showed no significant difference in eutrophication from those with the same areas uncultivated. Planting poor cover crops and planting crops in rows were found to be strongly related to sedimentation, while streams in areas with soil conserving farming practices showed significantly low sedimentation level compared to those without these practices. The conclusions arrived at were that: use of inorganic fertilizer may not be directly associated with the nutrient concentration but may be associated with eutrophication; planting poor crops, row planting and cultivating wetlands and riverine areas contribute to sedimentation of stream water, although wetland and riverine cultivation does not, on its own, significantly influence sedimentation and; soil conserving farming practices do not lead to clear stream water but they help in reducing the turbidity of stream water. It was recommended that the use of inorganic fertilizer should be minimized and instead, farmers should be encouraged to use organic manure. Planting of good cover crops, broadcasting, and controlled cultivation of wetlands and riverine areas should be encouraged. Extension officers and environmental officers should be involved in advising and educating farmers on how to manage their land, prudent use of fertilizers and, the risks paused by washing clothes, bathing and watering domestic animals at the stream.
Assesment of Climate Change Impacts on Natural Resources and the Different Gender among the Pastoralist Communities of Samburu,Kenya
(2013-03-21) Hyrine, Munga Gesare
Climate change due to anthropogenic induced global warming is one of the greatest and defining challenges of the current and future centuries. The Intergovernmental Panel on Climate Change (IPGC) has unequivocally affirmed it and directly linked it to anthropogenic Green-House Gases (GHGs) emissions from fossil fuel burning and land use changes. Although the impacts of climate change are global, they will be differently felt and distributed among different regions, generations, age classes, income groups, occupations and genders. Pastoralists, who inhabit the Arid and Semi-Arid Lands (ASALs), are among the people most likely to be affected by these impacts because of their high sensitivity and vulnerability, low adaptive capacities and resistance to climate change. For several years, they have been managing climate variability, however, the unprecedented rate arid scale of human induced climate change impacts; droughts and floods are beginning to pose bigger and more challenges to their livelihood sustainability. These impacts are affecting men, women and children differently due to different household roles; use of natural resources; differential access to resources, technology and education. This study was carried out in Wamba Division in the eastern area of Samburu County, to assess impacts of climate change on natural resources and gender. Specifically the study focused on identifying the key natural resources in the district and their use by different gender, assessing impacts of climatic hazards (drought and flood) on the key natural resources the subsequent effects on different gender and determination of gender specific coping strategies. Semi ;tructured questionnaires were administered to 36 households (Manyattas) per ranch randomly selected from five community group ranches. Key informant interviews, focus group discussions and specified transect walks were undertaken. The study revealed a 99.4% awareness level of climate change among communities. The most observed indicators included prolonged droughts (93.9%), loss of pasture (98.8%), increase in livestock diseases (81.1 %), and drying of water sources (78.9%). Key natural resources in the area in order of importance were rated as water, pasture, mountains and hills, medicinal plants, forests, wild animals and crops. The study showed females use natural resources more than males due to gender roles. Females main roles were herding of livestock, milking, collecting water, firewood, building materials, wild fruits and berries, fodder and charcoal burning whereas males roles included watering livestock, honey and bush meat provision. There were significant differences between livestock numbers owned in 2010 and those owned in 2005 and 2000 at p<0.05 . .A general trend of increasing malaria, typhoid, common cold and diarrhoea were observed and emergence and re-emergence of new livestock diseases. The study further revealed the females felt more impacts of drought and flood compared to males due to their many roles that rely on natural resources. The impacts on females were emotional and physical due to increased productive and reproductive roles. Impacts on males were more psychological. Females coped by livelihood diversification and diet change while males coped through herd management. Both genders used medicinal plants to treat and alleviate livestock and human diseases. The study recommends for the relevant ministries to introduce and train pastoralists on apiculture to supplement the already failing livestock production due to climate change a. It also recommends for activities or projects that can reduce women workload like provision of reliable clean and potable water and gender mainstreaming in climate change mitigation and adaptation policies.
Assessing consumer demand and economic value of non-timber forest products in Kakamega forest, Kenya
(2011-10-31) Kiplagat, Andrew Kipkosgey; Mugendi, D.N.; Mburu, John
Forests play a very important role in socio-economic and cultural development of any nation, Kenya being no exception. Of major concern to this study was the economic role Kakamega forest plays in the economy of rural households. Forests are a source of non timber products (NTFPs) such as firewood, herbal medicine, pasture, thatch, fruit, and vegetables for local communities. Because rural households largely depend on NTFPs for sustenance of livelihoods, it was important that household consumption patterns be understood so as to predict how trends may evolve in future with respect to conservation. It was also important to quantify and impute value to NTFPs consumed by households in order to establish how much forest resources contribute to rural household economies. This study analyzes the demand structure for NTFPs among rural households around Kakamega forest and quantifies their consumption. The economic value of NTFPs is also estimated using three methods: direct pricing, cost of collection and substitutes' approach. A consumer demand model, Almost Ideal Demand System (AIDS), is used to analyze household demand for NTFPs and predict its determinants. A random sample of 201 households was interviewed during the period of OctoberDecember 2006. Data collected include household characteristics, sources of NTFPs, quantities consumed per day, frequency of NTFPs extraction for household consumption, substitutes of NTFPs, unit prices and quantities consumed daily. In addition, data on distances and time taken to the forest, household value of time and forest management regimes were collected using structured questionnaires and interview schedules. The data was then sorted, coded and analyzed descriptively using a statistical package for social scientists (SPSS) to generate summaries in form of means, tables and graphs. Regression analysis on the demand model that had earlier been specified was also carried out with the aid of STATA computer package to determine factors that had significant influence on household demand for firewood. Results. highlighted important factors that influence the demand for firewood by the communities neighbouring the forest. In addition, results show the extent of dependence of NTFPs that include firewood, livestock grazing, medicinal plants and thatch grass. Main substitutes for the mentioned NTFPs included charcoal, napier, conventional hospital medicine and iron sheets respectively. Estimates from demand analysis indicated that age of household heads, participation in conservation awareness activities and sizes of household farms influenced demand for firewood. Comparison of NTFPs value estimates revealed that the substitutes approach had the highest value followed by cost of collection, and direct pricing approach the least. It was concluded that Kakamega forest contributes immensely to rural household economies. Several recommendations with policy implications are made to promote sustainable management of forest resources and the attainment of the Vision 2030 than seeks to improve conservation of forest resources and the incorporation of forest contribution particularly by NTFPs to the mainstream economy.
Assessing Health and Environmental Impacts of Quarrying In Embu County, Kenya
(Kenyatta University, 2024) Kinyua, Maureen Muthoni
Quarrying has been studied extensively throughout the world and has been shown to have an effect on the natural environment and human health. Positively, stone extraction has led to job creation and development of areas. On the negative side, quarrying leads to land degradation, noise pollution, production of dust and formation of cracks in nearby buildings due to vibration during the quarrying process. The situation is not different in Kenya since there’s increase in stone use as a result of growth of construction industry and the industry is faced with challenges of poor working conditions, poverty, inadequate occupational safety knowledge, and the absence of laws. The study sought a deeper understanding of these issues and used qualitative and quantitative data descriptive research design. Questionnaires were utilized to collect information from members of the local community, site management, and quarry employees. The impacts of quarrying on the environment, including the landscape, have been studied and documented. It was decided to employ stratified random sample to gather data from the area citizens, while purposive sampling was used to gather data from quarry laborers. It was necessary to evaluate the information acquired with the assistance of statistical package for the social sciences SPSS, which was used for cross tabulation, as well as for the creation of frequencies and statistical graphs for the purpose of data interpretation. It was decided whether there is a link between quarrying activities and the well-being of both quarry workers and residents of the immediate neighborhood using the Chi square test. In this study, a sample size of 100 respondents was used, and findings were obtained from 92 percent of those who responded. Findings from the studyagree with other studies done that quarrying activities cause harm to the environment and human health and that multiple approaches should be used to deal with the menace.
Assessing vulnerability to climate variability and change of focus crops small scale farmers in Wote Division-Makueni County, Kenya.
(Kenyatta University, 2016-01) Borona, Pius Mwenda
Climate variability and change are some of the most pressing environmental challenges of the globe and are associated with complexity and extreme events mainly drought and floods. Among small scale farming communities in Sub-Saharan Africa including Kenya, climate variability and change have been a more tasking challenge compared to the rest of the regions. There is little understanding of the vulnerability to climate change among such households in Wote based on their socio economic backgrounds. The main objective of the study was to determine the extent of vulnerability among small scale farmers in Wote division, Makueni County by specifically determining exposure, sensitivity and adaptation mechanisms as pertains climate extremes. The study was carried out between August and September 2013. The study targeted selected farmers cultivating drought tolerant sorghum, cow peas and pigeon peas which are some of the dominant multipurpose crops in the area and are also key means of food security. Random and purposive sampling methods were applied in identifying households cultivating all the three focus crops. Data collection methods and sources included the use of focused group discussions, semi structured questionnaires and secondary climate data from the meteorological department. The collected data was entered and cleaned using CSPro program and later exported to Ms Excel and SPSS for coding and analysis. Descriptive and inferential statistics approaches included correlation, chi square, non-parametric tests and regression. Household characteristics included main respondents and correspondents, 86% and 76% respectively, engaging in farming as the main occupation with 86% of household’s main income obtained from on farm produce. Results showed that households have been exposed to calamities in form of; drought, 100%: crop pests, 93%: crop diseases, 83% and erratic rains, 59% with drought ranking highly ( =1.06,=0.28).Crop diseases significantly related to occurrence of crop failure,2=24.860,p=0.000 and Cohen’s index=0.445 showing a medium relationship. Drought however did not show a significant relationship with crop failure, p=0.334.Temperature data indicated an annual trend of 0.21220C (R2=0.4881) per year with annual means varying significantly, p=0.002. Annual rainfall indicated an annual trend of -0.0708mm (R2=0.0016) with non-significant seasonal variation, p=0.166, p=0.189 for March-May and October-December rains. Average number of calamity adaptation means were 8, =8.53,=2.230,with key mechanisms being pesticide use, 32.5%:drought resistant crops,65%:crop diversification,13% and terracing, 28%. A multiple regression model F (9, 51) =2.655, p=0.013, R2=0.319 indicated that age, gender and acreage influenced adaptation means significantly: p<0.05), p=0.027, 0.043, 0.011 respectively. Further vulnerability analysis indicated most of the households; 79% experienced more than 2 months of food insecure months ( =3.75,=1.49) with such food insecurity correlating significantly with households income (p=0.001,=-.316). Results demonstrate vulnerability due to high dependence on rain fed farming with minimal alternative income and instances of food shortage .The study mainly recommends adoption of alternative income activities, including on farm value addition to supplement farm based income and at the same time enhancement of indigenous and effective modern adaptation mechanisms to enhance adaptive capacity.
Assessment of Drinking Water Quality in Shallow Wells in Koitoror Location of Uasin Gishu County, Kenya
(Kenyatta University, 2015) Kipchumba, Kibiwott
Information on the quality of water in water bodies is important as it forms a vital baseline for among others the detection of undesirable change in water quality. Water supply in the study area is mainly from shallow wells whose quality is influenced by human activities which cause pollution at the land surface. It is unfortunate that the water is used for drinking in the assumption that it is safe for intended use. This is compounded further by the fact that there is no alternative source of water and at the same time data on the status of water in shallow wells within Koitoror location is totally absent. The levels of physicochemical parameters in shallow wells in Koitoror location, Uasin Gishu County, Kenya were investigated over a period of six months between November 2012 to April 2013. The aim of the study was to find out the levels and variations of physicochemical parameters in shallow wells. Water samples from 11 Shallow Wells were collected during the dry and wet season. The physical parameters including Total Dissolved Solids, Electrical Conductivity, temperature and pH were measured on site by the use of HQD40 Multi parameter Meter. Concentrations of nitrate, phosphorus, nitrite and cadmium were determined by the use of DRSOOOspectrophotometer in Aquatech Industries Ltd, Nairobi. Data was analyzed using SPSS and the results presented in form of tables and graphs. The study revealed that during the dry season the mean levels of Total Dissolved Solids were 39.08±0.62 mg/L; Electrical Conductivity (IlS/cm) 81.97±lAl, Temperature (OC) 14.96±0.28, Phosphorus (mg/L) 0.S6±0.02, Nitrate (mg/L) 7A6±0.18, Nitrite (mg/L) 0.OS±0.002,pH S.99±0.03. During the wet season the mean values were, Total Dissolved Solids (mg/L) 41.63±0.66, Electrical Conductivity (IlS/cm) 87.39±1.47, Temperature (OC) 14.64±0.3S, Phosphorus (mg/L) 0.64±0.02, Nitrate (mg/L) 8.18±0.17, Nitrite (mg/L) 0.06±0.002 and pH 6.10±0.03. There were seasonal ~ariations in the levels of concentrations in the measured parameters other than cadmium which was found to be nil. During the wet season the concentrations were higher in all the measured parameters. Also the study revealed that, the levels of nitrite in both dry and wet season were above the set specifications for drinking water based on KEBS Standards. Based on the tested parameters, the shallow wells in Uasin Gishu County (Koitoro Location) do not meet the threshold values for drinking water as prescribed by KEBS. Residences of Koitoror are therefore advised to seek alternative source of water for drinking purposes. The water can also be treated so as to render it fit for domestic use.

Browse

Browsing MST-Department of Environmental Science by Title

Results Per Page

Sort Options