AbstractKiambu county has generally been an agricultural area with a focus on horticulture and cash crop farming that had coffee as its principal crop. This is slowly changing despite Kiambu County being a high potential agricultural zone. Its prime land is rapidly being converted to non-agricultural uses particularly through the booming housing and real estate industry. Whereas the housing industry generates quick and sustained income for a minority high income investors, its direct contribution to the reduction in ecosystem goods and services needed for improved livelihoods should worry land use planners and policy makers. While loss in coffee production is the biggest challenge in the emerging land use changes, the potential for growing other essential food and income crops is declining. Food and nutrition insecurity are therefore likely to remain key development concerns. Other land use changes that have been caused by a shift in source of income includes quarrying sand, marram and rocks which are used in the construction sector in Nairobi and environs. Unchecked loss of land also threatens availability of other benefits like water supply and wood fuel. Equally important is the long-term effect on inherent ecosystem health (Agastiva, 2006) . Consequently there is need to align current trends in land use changes to Kenya’s Vision 2030 (Republic of Kenya, 2007) , the constitutional right to food and healthy environment (Republic of Kenya. 2010), and to sustainable development goals. Rapid urbanization and urban growth, particularly in the developing worlds, is continuing to be one of the crucial issues of global change in the 21st century affecting the physical dimensions of cities. This process, with no sign of slowing down, could be the most powerful and visible anthropogenic force that has brought about fundamental changes in urban land cover and landscape pattern around the globe. Understanding and quantifying the spatio-temporal dynamics of urban growth and its drivers is critical to put forward appropriate policies and monitoring mechanisms on urban growth and make informed decision. In this study, the spatio-temporal patterns and processes of land use changes of Ruiru and its drivers will be investigated from 2000 by using satellite remote sensing images, spatial metrics and analysis of the statistical data gathered. (Abebe, 2013) The rapid land use degradation, especially in developing countries will continue to be one of the crucial factors that must be considered in the human dimension of the 21st century (Torrey, 1998). The lack of basic knowledge of the landscape attributes to hydrology and its ecological impacts has made us unable to access, much less to manage and restore limited water resources in the country. Therefore, timely and accurate estimation of implications of population systems to land use attributes is of considerable significance for decision makers in watershed planning and for a better understanding of the relationships between population growth, economic and environmental conditions (Yu & Changshan, 2004) . Despite these dire needs to monitor ecosystems, the ecological and health values of the Ndarugu River and Ruiru River catchment, particularly within the settlement and agricultural areas are not yet fully addressed. Land use and land cover maps covering Ruiru Sub-County will be produced to guide policy analysis and land use planning and development in the County. Awareness on the part of land users on land use changes that fit the notion of “designed for the environment” (i.e. environment and people friendly) will be created through sharing of findings with the various stakeholders in the sub county. Acronyms and AbbreviationsGISGeographic Information SystemICRAFInternational Centre for Research in Agro ForestryKEFRIKenya Forestry Research InstituteLULCLand Use Land CoverNDVINormalized Difference Vegetation IndexNEMANational Environmental Management AuthorityNSDINational Spatial Data InfrastructureRSRemote SensingUNEPUnited Nations Environmental Program IntroductionBackgroundProblem statementRapid transformation of agricultural land into built environment without clear knowledge of how key agricultural products and services will be provided in future should worry development policy makers and actors in Kiambu County and Kenya at large. Traditionally shifts in land use changes away from agriculture have been caused by the inability of land to yield agricultural benefits in the context of changing market opportunities and also people’s survival dynamics (Gruhn et al., 2000; Bationo et al., 2006). While self-driven changes in resource use are permissible in liberalized market systems, strategic interests in pursuit of the greater public good should invoke limits on losses of prime agricultural land, private land tenure notwithstanding. Kiambu County, such land losses are mainly attributed to the growing demand for real estate investments. Although much income may be realised by the investors, the benefits are generally low to the wider resource-poor community. Further, reduced availability of farmland means increased intensification and hence high risks of degradation and poverty. To date, there is scanty documented knowledge on the impact of emerging land use changes on essential ecosystem services in the County like overall food security, supply of wood fuel, conservation of wetlands and community security among others. The question that arises is whether the apparent rapid transformation in land use in Kiambu is guided by any land use master plan and policy with deliberate effort to save and preserve prime agricultural land for posterity, in a country where much of the land area is arid and semi-arid (www.aridland.go.ke/ and UNEP, 2009), and food insecurity and poverty remain pressing challenges more than 50 years after independence. In addressing the above problem, Kiambu County was chosen for being exemplified by unprecedented changes in land use; and its proximity to Nairobi city, which would provide learning opportunities on how to balance rapid urbanisation and the greater good of preserving agricultural land for posterity.Objectives The overall objective of this study will be to contribute to efforts of saving agricultural land from unnecessary non-agricultural uses in pursuit of food security and overall sustainable environmental management. The specific objectives will be: To assess the relative importance of land use changes that have occurred in Ruiru Sub-County, Kiambu over the last 15 years.To analyse the causes of observed land use changes in the study areaTo assess the effects of emerging land use changes on community living standards, with special focus on food supply, availability of wood fuel and domestic water supply.To assess future status of land and its implications on essential ecosystem services for food security planning and environmental healthResearch questionsWhat is the area of the land that has undergone change in each of the classification zones?What are the causes of land use change in the study area?What are the effects of emerging land use changes on food supply, availability of wood fuel and domestic water supply?What is the future status of land and implications on essential ecosystem services?HypothesisThere is a negative relationship between changing land use and critical livelihood indicators, particularly those related to tangible ecosystem services.Significance of the study Conceptual/theoretical framework (where applicable)The relationships between the variables in the study will be investigated based on the Millennium Ecosystem Assessment framework. The relative importance of key drivers of land use changes, their effects on agricultural land and their ultimate effect on community well-being indicators will be analysed as the basis for strategic interventions and planning for future land use in Kiambu County. The research will thus seek to answer the following questions:Why are land owners increasingly shifting land use away from agriculture? How much prime agricultural land has been lost in the last 15 years?How have these changes in land use affected availability of area produced food, availability of wood fuel and preservation of natural water resources?How have these changes affected the living standards indicators of land users measured based on the five components of human well-being in the MA-framework?Which scenarios for the future should be expected if current trends in land use continue unabated?Definition of termsBiodiversity: It is the abundance of the species in an area, both flora and fauna.Conservation:Scientific planning of the use of Natural resource.Degradation:Loss of the aesthetic value of an area as a result of the human interference.Ecosystem:Self sustains natural systems of plants and animals interacting with each other plus their physical environmentEncroachment:Introduction of the anthropogenic factors in an area leading to the interference of the natural ecosystemPreservation:Keeping natural areas pristine and wildRiparian zone:Areas adjacent to wetland being a minimum of 6m to maximum of 30m on either bank from highest water mark.Wetland degradation:The impairment of wetland functions as a result of human activitiesWetland loss: Loss of wetland area, due to the conversion of wetland.Remote Sensing:Refers to the science and art of acquiring earth information without necessary being in conduct with the earth. This is done by receiving satellite images, recording them and then analysing them to generate information of a specific earth surface.Urbanization:This is the process of growth and development of urban areas replacing the natural land uses and the agricultural land practices. Urbanization is characterised by increased shift of lifestyle from the rural practices such as agriculture and forests to secondary land uses such as Building, high density residential, infrastructures and improved utility services.GIS:This is an acronym geographical Information system. It refers to the use of geo referenced data to visualize, question, analyze, and interpret cases in order to understand relationships, patterns, and trends on the land Literature reviewStudies that have been carried out in Murang’a, a neighbouring county, show a complex reality with interaction between different factors. For example soil nutrient status and yields depend on farmers’ resource levels, slope position, land management and soil erosion (Ekbom, Knutsson, & Ovuka, 2000). In order to generalise and extrapolate findings from the complex reality, knowledge regarding the area of concern is required. The interpretation and field verification of large-scale aerial photographs, surveys of relevant literature and interviews with farmers methods could be used for further studies, but there are also other data and materials that can be used to examine LULC changes, e.g., small-scale aerial photographs or satellite images. For example, vegetation status is studied from satellite images, which show large-scale changes (Lindqvist & Tengberg, 1993) (Fairhead & Leach, 1998). Some detailed information can, in this case, be lost, but the advantage is a larger picture of the changes. Small-scale photographs as well as satellite images need field verification. Even with this technique farmers’ knowledge about the area will contribute to increased understanding of the changes. But extrapolating farmer’s perception of environmental changes to larger areas could be difficult mainly as a result of local diversities. In order to verify large-scale environmental changes with farmers’ perceptions, knowledge regarding the investigated area is required, to be able to interpret farmers’ answers from random tests correctly (Ovuka, 2001).LULC changes have previously been investigated by use of Remote Sensing and Geographic Information Systems (GIS) in Rize, a region in North-East Turkey (Reis, 2008). For this purpose, the supervised classification technique was applied to Landsat images acquired in 1976 and 2000. The methods gave satisfactory results with good classification overall accuracy. Most of studies have addressed that post-classification comparison was found to be the most accurate procedure (Mas, et al., 2004) MethodologyStudy areaPopulationIn 1991, Ruiru sub county then a district had a population of over 100,000 people while in the year 2009 census, it had grown to a population of over 238,858 people. Currently, the population is extrapolated to at over 299,067 people (Kiambu County, 2016) signifying an increase in population growth mainly attributed to migration of people from Nairobi as a result of housing shortage. Kiambu County is a county in the former Central Province of Kenya. The capital of Kiambu County is Kiambu and its largest town is Ruiru. Ruiru, a town emerging in terms of population and economic growth as witnessed in recent years has benefited immensely from the construction of Thika Super-Highway and other projects that are Underway. The County is adjacent to the northern border of Nairobi County. Economy Kiambu economy prides in rich highland soils coupled with very favourable climatic conditions, agriculture plays a very important role in the county’s economy. However with its proximity to Nairobi and limited land resources, the services sector is slowly replacing agriculture as a major economic activity. The county is undergoing rapid urbanization as a result. The county is predominantly rural, but its urban population is increasing as Nairobi is growing rapidly. Among the top ten cities and towns in the country, Ruiru is ranked as the sixth most populated region, housing more than 100,000 people. The first five are Nairobi, Mombasa, Kisumu, Nakuru and Eldoret. Education The sub county has a high number of learning institutionsResearch design.Sample size and sampling procedureData collectionData Collection Methods Both quantitative and qualitative research and statistical approaches and procedures as described by among others Neeman (1994), Fink (2003) and Freund (2003) will be used in this work. Earth observation software (ArcGIS and ERDAS) and interpolation techniques will be utilized to analyze earth surface characteristics. Specifically data will be collected using the following methods: i. Tracking Changes in Land Use and Environmental Quality Spatial-temporal analysis of changes in land cover and land use will cover the period 1985-2015. This will be accomplished through use of participatory transect surveys, environmental checklists and GIS techniques. The main output will be land cover and land use maps detailing variations in physical indicators of land quality (evidence and extent of physical land degradation and natural water bodies) through time, causes of the changes and their negative and positive impacts. The graduate student working on this theme will be facilitated in acquiring more training in spatial analysis and use of GIS during course work. ii. Questionnaire Surveys and Interview Schedules Since resource users play a critical role in land use dynamics, researcher-administered questionnaires will be used to gather information from a representative sample of about 400 land users in the study area. This will help address effects of land use changes on the five components of human well-being based on the millennium ecosystem assessment framework, thus: having materially enough for a decent life, enjoyment of good health, having good social relationship, and feeling secure and having the ability to make choices and preferences. The economic effects of the changes in land cover-land use will be analysed from secondary data (national and county economic survey documents and development plans) covering the same period. Face to face interviews will be used to gather information from key respondents such as officers from line ministries and key government agencies that directly or indirectly resonate with the five components of human well-being. iii. Focal Group Discussions Two Focal Group Discussions (FGDs) will be used to verify and add value to data collected through individual questionnaires and interviews. The brainstorming that is inherent in this method will also be helpful in building consensus among land users and other stakeholders, including those who can influence policy choices, on issues under investigation and possible strategic interventions. A final feedback workshop will be held in which the stakeholders will provide input to the tentative conclusions and help to sharpen the findings as part of this participatory, action research approach. Apart from being involved in decision-making at the beginning of the research, key stakeholders will also participate in developing solutions and implementation strategies to identified problems in land use changes. Participatory approaches provide platforms for initial dissemination of research goals and outputs, thus having direct bearing on community livelihoods. iv. Secondary Data Secondary data will be critical in analysing past trends, identifying some gaps based on current conditions and providing the basis for corroborative analysis. Such data will be obtained from among others economic survey records, national/county development plans, the National Land Policy, the 2010 national Constitution, Physical Planning Act, and Agriculture Act. Identified gaps will also be debated and analysed during the focal group discussions and subsequent dissemination workshops. v. Exploratory Scenarios Analysis (ESA) Though various modelling methods can be used to predict the future, an exploratory scenario analysis approach as described by Alcamo et al (2003) will be adopted in this study. Exploratory scenarios analysis seeks to predict the future based on current happenings as the bench mark (pace setter). A negative future on one or several indicators would mean that current happenings, which could be technology, resource use dynamics, governance approaches, policies, legislation, and culture among others, may be wanting and thus desirable of amendments in order to avoid a future doom scenario. A positive outlook for the future would mean that the way things are being done presently is right, and thus the gains should be consolidated and maximised. The output will thus lay the foundation for long-term planning in sustainable land management (use, care and improvement) and enhanced livelihoods within Kiambu County. Vi Data Analysis The physical status of land will be analysed using standard GIS procedures and transect surveys. Questionnaire data will be coded and subjected to both descriptive statistical analysis and analysis of variance using appropriate statistical software. FGD data, secondary data and scenarios data will be analysed using content analysis.Data analysis3.5.1 Satellite imagery analysisThe supervised classification technique is preferred, because the data of the study area is available and the author has a prior knowledge of the technique. LULC changes will be investigated by using of Remote Sensing and Geographic Information Systems (GIS).For this purpose, the supervised classification technique is applied to Landsat images acquired in the past 15 years with an interval of five years. Image Classification of six reflective bands of two Landsat images will be carried out by using maximum likelihood method with the aid of ground truth data obtained from aerial images that will fall within the time epochs under study. The Maximum Likelihood algorithm is a common method, but it is appropriate and efficient method in such uneven study area. It is still one of the most widely used supervised classification algorithms (Wu & Shao, 2002) . The change detection technique, which was employed in this study, was the post-classification comparison. Most of studies have addressed that post-classification comparison was found to be the most accurate procedure (Mas et al 2004, Yuan et al. 2005).