In this present study an evaluation of a daily variability of suspended sediment flux of the river Cirhanyobwa, one of the important tributary of Lake Kivu, is reported. A daily sampling was done during one year. Suspended sediment and discharge was measured using standards method and floating method respectively. The results shown that agricultural has a impact on the transport of suspended sediment in this river. The quantity of suspended sediment in the river Cirhanyobwa was high during the beginning of the first tillage in July-August and February. Daily Suspended sediment and flux increased with daily flow. Ecological techniques are useful to prevent the suspended sediment transport in the river bed. These techniques consist of agricultural practices and conservation of river bank.
Malacological and epidemiological investigations have been done in Katana Health Zone during the period from 2001 to 2011. The results shown that the schistosomiasis exists and constitutes a problem of health in this region. A total of 189,475 stools examinations and 11,000 of urines done during the ten years passed; 1,904 cases of schistosomiasis due to Schistosoma mansoni have been observed. That is a rate prevalence of 0. 95 % and 39 cases of Schistosoma haematobium have been recorded. That is a rate prevalence of 0.35 %. Methodical treatment per os of infested subjects by Ambilhar and the control of intermediate host by molluscicidal no toxic to human and environment are measures to take immediately.