|| 要旨トップ | 目次 |||日本生態学会第61回全国大会 (2014年3月、広島) 講演要旨
一般講演（口頭発表） G1-09 (Oral presentation)
Water erosion is one of the main factors causing soil fertility depletion in agro-ecosystems of East Africa as it removes the fertile surface soil and is predominantly influenced by soil texture and soil moisture content. In this study, four different experimental sites in terms of soil and climate conditions were selected in the Uluguru Mountains of Tanzania to compare the water erosion characteristics. The amount of rainfall and runoff, and the fluctuation of soil moisture content every 10 minutes were evaluated by using a data logger system over a rainy season (160 days).
Results showed that total sediment loss varied from 15.9 to 36.1 Mg ha−1, and total runoff amount varied from 62.7 to 180.5 mm. Both the sediment loss and runoff amount were significantly correlated with total rainfall. However, the runoff ratio varied substantially from 11.1 to 16.6% because of crust formation, which suppressed water infiltration into the soil and resulted in a high runoff ratio. According to the analysis of every rainfall event, runoff ratio was decreased when the initial soil moisture content was low. Sediment concentration in runoff water varied from 17.8 to 36.4 g L−1, and the highest concentration was recorded in a sandy site.