Abstract
In order to build a connection between former study of fine sediment yield and former study of rainfall system, the observation of raindrop size distribution and sediment yield has been made in the Lesti river basin that is a tributary of the Brantas river in Indonesia.
The following results were obtained. Rainfall energy work which are calculated by size distribution obtained by MRR has good relationship with rainfall amount obtained by a raingage. The energy which is used for calculating sediment yield is proven to be treated as linear to rainfall amount. On the other hand, the spatially non-uniform rainfall is shown in the Lesti river basin. The methods for treating the limited rainfall data is proposed in this study. Finally, the accumulation and erosion of sediment is observed in three points in the Lesti river basin. Moreover, main items which are important to estimate the sediment yield is picked up by the observation.
