Abstract:
The Central Region of Kenya has undergone significant changes in land cover due to a broad range of drivers. These changes
are more pronounced in forestland conversions. Past researches within the study area have identified drivers of land cover
change without quantifying the influence of these drivers. Predictor variables include population density, precipitation,
elevation, slope, forest fires, soil texture, proximity to roads, rives and towns. Land cover changes were analyzed using
multi-temporal land cover maps between year 1990 and 2014. Boosted regression trees model was applied to determine the
significant drivers and quantify their relative influence on key forestland transitions. The local and spatial influence of the
drivers has further been analyzed by geographical weighted regression using coefficients determined at each sample point.
Significant land cover changes continuously occurred over the study period. Forestland reduced from 38.90% in 1990 to
38.14% in 2014. Grassland reduced from 32.59 to 22.57%, cropland increased from 28.05 to 38.83% and wetland changed
from 0.07 to 0.04%. Other land which constitutes of bare land and built up increased from 0.38 to 0.42%. The results show
population density had the highest contribution to forestland changes throughout the study period, with a minimum contribution
of 20.02% to
a maximum of 26.04%. Other
significant variables
over
the
study
period
are
precipitation,
slope, elevation
and
the
proximity
variables.
The results
indicate that
the
relative
influence of the
drivers
to
forestland
conversion
varies
with
time, location and type of transition.
