Assessment of the Land Use/Land Cover Change in Koitobos River Catchment, Trans Nzoia County, Kenya

Abstract

Globally, many countries are facing pressure to meet the livelihood needs of their fast-growing populations. This often leads to overuse of natural resources and consequent encroachment on fragile ecosystems such as river catchments and riparian areas mostly in developing countries. The objective of this study was to assess the implication of land use, land cover changes on surface water acreage in the Koitobos River catchment. Specifically, the study assessed the extent of land use/land cover changes with data being based on Landsat images pertaining to the period of study, 1992 - 2022. The research design used was correlations where the Google Earth Engine (GEE) and Remote sensing techniques were used for the analysis with in-depth review of journals and research reports. A sample size of 384 respondents, according to Krejcie, & Morgan as drawn from a target population of 203,821 residents within the study area. The survey data was analyzed using SPSS software version 25 and the Microsoft excel. The results were presented in form of frequencies, charts, maps, and tables. The findings of Land Use/Land Cover Change for the years 1995, 2009 and 2022, showed that Agricultural Land covered most of the study area with a cover of 26,853Ha, (58%), 32,438 Ha (70%), and 36,118Ha (77.68%) respectively. When transitioning through the years, thus shows drastic increased changes in area. This was followed by bare land area which covered an area of 14,915 Ha (32%), 8,093 Ha, (17%) and 6175 Ha (13.28%) for the years 1995, 2009, and 2022 respectively, of the entire catchment area which extremely decreased transitionally as the agricultural land increased due to the pressure exerted on the resource. The forest land showed a drastic decreasing trend through the transitional period from a cover of 2242 Ha (5%) to 1647 Ha (4%) and then 222 Ha (0.48%), due to an increasing demand for space by the growing population as depicted by the Kenya National Bureau of Statistics (KNBS) reports, which increasingly resulted to deforestation activities. The coverage for the agricultural land in the years 1995, 2009, and 2022 spread all over the area separated by patches of bare lands, water, and forests. The population of the study area in 2009, was 166,524 persons and 203,821 persons in 2019, within an area of 465.3 square Kilometers with residents’ density of 438.0 per square kilometer. The study found out that due to a 2% (percent) annual population change over the period 2009 to 2019, this resulted in an increased demand for food production and therefore concluded that environmental policies and laws needed to be adopted together with sustainable land management practices for healing and conserving biodiversity in Koitobos river catchment. The study therefore recommended the adoption of sustainable land use management practices that continually have the potential to heal the land and conserve biodiversity in Koitobos river catchment.