Anthropogenic Impacts Of Land Use And Land Cover Changes On Mai Mahiu Ecosystem, Nakuru County, Kenya

ABSTRACT

Land-use changes are the main cause of human and environmental problems especially in

many developing countries in Africa and Asia. Study was conducted in Mai Mahiu,

Nakuru County, Kenya whose aim was to assess the impacts of land-use and cover

changes on the ecosystem functioning and human environment. Specific objectives were:

(i) to understand the nature of land use practices (ii) to monitor impacts on soil quality;

(iii) impacts on vegetation composition and structure; (iv) to examine the level of

variation in the physico-chemical parameters of rivers; and (v) to assess the effect of

land-use change on climatic variability. GIS technology was used to establish landuse/

cover changes from 1985 to 2015. Soil samples were collected for physical and

chemical analyses from five land-use practice namely; undisturbed forest, disturbed

forest dominated by Croton spp., disturbed forest dominated by Tarchonanthus

camphoranthus, cropland and severely grazed grassland while Transect method was used

for vegetation survey. Water was sampled at four sampling stations (A, B, C and D)

which are sites where the river passes through the above mentioned land-use practices

and analyzed for physico-chemical parameters while climate data was used in climatic

variability analysis. Analysis of variance, regressions and mean separation at 0.05

significance level were excuted on the data using GenStat 14th edition. Results showed a

remarkable land-use and land-cover change between 1985 and 2015. Cropland

significantly increased by 135% from 27.3 km2 in 1985 to 64.2 km2 2015 at the expense

natural forest. Built-up area and roads coverage had increased by almost three times from

9.8 to 29.9 km2. Soil quality deteriorated significantly with land conversions. There were

significant changes in soil bulk density (p