Conference Book of Abstracts - Taita Taveta University College

ased study of archaeal community structure in various higher termites, including wood-feeding,soil-feeding, and fungus-cultivating species. Highest diversity of methanogens was observed inthe soil feeders, where representatives of almost all major lineages were present, including aclade of uncultivated archaea distantly related to the Thermoplasmatales, which represent anovel lineage of methanoarchaea (K. Paul, J. Nonoh, and A. Brune, in preparation). The densityand distribution of archaea in the different termites and gut compartments was compared byqPCR analysis. Experimental stimulation of methanogenesis in gut homogenates of Cubitermesugandensis indicated that community structure in the different compartments microenvironmentsis shaped by exogenous factors, such as oxygen status and the availability ofmethanogenic substrates.Assessment of Sedimentation of Masinga Reservoir and its Implication on the Capacity ofthe Dam for Hydropower GenerationBunyasi, Muzungu Martin¹ and Onywere, Simon Mang’erere²¹ ²Department of Environmental Planning and Management, Kenyatta University, KenyaContact email: martinsembie@gmail.comMasinga Dam was commissioned in 1981 and has a full operation surface area of about 125 km 2that extends about 45 Km upstream. The Dam is the largest of the Seven Forks Hydro ElectricPower (HEP) project dams with a design capacity of 1,560 million m 3 . Masinga catchment ispart of the Tana River basin and covers an area of about 6,255 Km 2 traversing 9 countiesnamely; Murang‟a, Nyandarua, Kirinyaga, Kiambu, Laikipia, Machakos, Kitui, Nyeri and Embu.The Dam has installed capacity of 40 MW and also plays the role of regulating water flow intosubsequent dams and controlling downstream flooding. Masinga Dam therefore directly affectsthe seven forks hydropower project with about 55% of Kenya‟s generated energy. The Dam isthreatened by loss of water storage capacity due to increased dam sedimentation which is linkedto the watershed agriculture activities and land use patterns, river characteristics, and reservoirlocation and design. Rapid human population increase in the region at a rate of about 13.6%between 1969 and 2009, has led to increased catchment settlement and farming on steep slopeswithin the catchment, leading to rapid soil erosion. The dam‟s high trap rate of up to 98%yielded about 23 million m 3 loss of water storage volume annually in its initial years. By 1988about 6% (93.9 million m 3 ) of the dam‟s storage capacity had been lost due to sedimentationresulting in rapid loss of a stable hydraulic head. This raised concerns on HEP capacity of theTana hydro-dams. To develop an effective catchment management strategy to improve the dam‟ssedimentation regime, this research assessed how Masinga catchment activities have affectedMasinga Dam‟s storage capacity and hydropower generation. The study assessed the level andtrend of sedimentation of Masinga Reservoir and the relationship between Masinga catchmentvegetation cover change and sediment loading into Masinga Dam. The study also determined thecorrelation between Masinga Catchment precipitation and temperature trends, and Masinga daminflows and sediment loading and its effects on hydropower generation capacity. The dataanalysis methods utilized included the Normalized Difference Vegetation Index (NDVI) usingArcGIS 10.0 and ERDAS IMAGINE 9.1, statistical analysis using SPSS software for correlationanalysis, and descriptive and inferential statistics. The research findings indicated that thecatchment temperate is rising by 0.02 0 C annually, the rains are declining by 3.9 mm annually,Masinga reservoir inflow is dropping by 0.74 cumecs annually, catchment forest is shrinking by