Merga Hailemariam Urgesa and Belete Yilma
Vertical variation of the physic-chemical corporations of bottom sediments per two centimeter intervals was the main objective of this research. The samples were collected from three deferent lake stations (inflow, deep and outflow) in Feb. 2015. Different parameter pH, electrical conductivity, salinity, major ions (Mg++, K+ , Ca++, Fe++ and Na+ ), total organic matter and total organic carbon were analyzed. The average concentration of pH 7.31, conductivity 378.61μS/cm, salinity and 0.337‰ were recorded. Maximum total organic matter 74.33g/kg and maximum total organic carbon 24.31g/kg was recorded at the upper part of sediment mainly at the inflow station. Some of the concentration increased at the inflow sampling station, like organic matter and organic carbon. Vertically only organic matter and organic carbon decreased down the depth, but other are varied within the depth. Likewise some concentration increased at the outflow station. In a deep lake to decrease the human impact, suspended particles, the tendency to changes the chemical contaminate along the sediment profile but other stations affected. Similarly at the inflow station indicates significant increase in water contribution it have a power to change sediment chemistry. The changes in chemical composition of bottom sediments beside with depth point to periodical increases in fertility as a result of waste suspended particles from inflow. In an outflow lake, the related variation has indicated disturbances in the mechanism of sedimentation ret. All data analyzed using SPSS, excel and one-way ANOVA. Statistically strongly positive correlations between the content of organic matter and total organic carbon were found.