| dc.description.abstract | Groundwater depletion is on an increasing trend. Soil moisture content plays a major role
in plant growth, nutrient transport, and oxygen balance. Assessment of soil water balance
is crucial for understanding water dynamics to optimize water and fertilizer use. The
main objective of the study was to examine the effects of land cover on groundwater in
the middle Yala catchment, Kenya.. The specific objectives of this study were to
investigate the groundwater recharge rate, to evaluate soil water distribution in the vadose
zones for various land uses and to simulate the effects of various land cover on the flow
in the vadose zone. Rainfall, Evapotranspiration, and root water uptake will be the main
components of water balance. Therefore, intensive field experiments and HYDRUS-1D
numerical modelling were applied to investigate the effects of land cover on groundwater
dynamics. Primary data in this study were collected under varying environmental
conditions: tree canopy and grassland plantations. Secondary data were collected from
the weather station in Vihiga County. The HYDRUS 1D model was used to simulate the
relationship between the two simulated scenarios under varying soil texture. Rainfall and
soil data were combined with temperature and humidity collected by TMS sensors as
model variables to determine the trends in water fluctuations. The findings revealed
grassland sites maintained an average volumetric moisture content (VMC) of 32–35%,
while eucalyptus sites dropped to as low as 18–20% during peak dry periods. The impact
of seasonal rainfall patterns varied on the soil moisture, and the rate of simulated recharge
in grassland was 4.2 mm/day on average as opposed to 1.6 mm/day on average in the
area with eucalyptus cover. The model was able to well describe the trends in soil
moisture in grassland but the interactions with eucalyptus were a problem. Finally
choosing vegetation covers that boost recharge of groundwater and recommends
controlled growth of eucalyptus is significant to sustainable farming. Future research
suggestions are the long-term monitoring, investigation of various vegetation effects, and
the combination of climate change and remote sensing technology. These observations
are important in enhancing management strategies of groundwater and how land cover
practices contribute to sustainability of groundwater in the area. | en_US |
