Authors: Juma GS 1, Nebat Kituni1, Makokha JW 2
1 Department of Mathematics, Kibabii University, Kenya
2 Department of Physics, Kibabii University, Kenya

ABSTRACT
Advection is defined as a conservative transport of a substance by bulk motion. The substances include pollutants, enthalpy or any material that contains thermal energy. This paper introduces the concept of advection as applied in air pollution modelling of possible pollutants using Hybrid Single Particle Lagrangian Integrated Trajectory Model (HYSPLIT). A three dimensional (3-D) advection equation is specified and a graphical output of a forward air trajectory given over Busia County. The study reveals transboundary flow of air pollutants to the Eastern parts of Uganda and across counties in Western, Central, Rift valley and Eastern Kenya respectively. An intercounty environmental monitoring policy framework is recommended in this study due to the transcounty nature of air pollution issues.

Keywords: Kenya, Busia County, Advection, HYSPLIT