Twesigye, Charles K.; Onywere, Simon M.; Getenga, Zachary M.; Mwakalila, Shadrach S.; Nakiranda, Josephine K.
Description:
The impact of land use activities on loss of vegetation cover and water quality was assessed in three selected
sites within the Lake Victoria Basin using remote sensing technologies and standard water quality analysis techniques.
The three study sites were: (i) Nzoia River Basin (Kenya), (ii) Nakivubo Wetland (Uganda) and (iii) Simiyu drainage
basin (Tanzania). Lake Victoria is the second largest fresh water lake in the world and is served by a drainage basin area
of over 193,000 km2
, traversing five East African Community States; Kenya, Uganda, Tanzania, Rwanda and Burundi.
This paper examines the impact of land use activities on vegetation cover and water quality based on remote sensing and
Geographical Information Systems analysis combined with chemical and physical water analysis. The quality of the
effluent generated by the industries found within the study sites and their effects on downstream discharge was also
determined. Pesticide residues in soil and water samples were determined using analytical standard methods. Soils from
some selected fields in Nzoia River basin showed high levels of compounds such as aldrin, dieldrin, endosulfan, DDT,
and endrin which are together referred to as persistent organic pollutants (POPs). The physical and chemical analysis of
water quality revealed high levels of phosphates and nitrates along the agricultural zones of River Nzoia Basin. The
satellite images revealed that in all the three study sites land vegetation cover has continuously reduced in size. The extent
of environmental degradation caused by agricultural, domestic and industrial wastes and how this affects loss of vegetation
cover and water quality is discussed.