There are many researches on deterioration rate of wood, but almost these researches just focused on finding out the deterioration rate according to time directly basing on the in]field sampling. These researches mentioned that weather factors are the reasons that cause the deterioration of wood; however, did not show the relationship between the deterioration rates with these factors. Therefore, we have measured the deterioration from 6.0 to 9.0 years at the seven wooden crib dams in Kyoto Prefecture. Wood species are Cryptomeria japonica (Sugi) and Chamaecyparis obtusa (Hinoki). In addition, we calculated the design high water level of overflow depth, warm index, and maximum snow depth at the dam sites to clarify the relationships between them. The design high water level was calculated from Manning's formula. Warm index and maximum snow depth were obtained from the previous studies. The obtained results showed that there is a significant relationship between deterioration rates with design high water level. In the case of dam built at the torrent bed, the warm index and maximum snow depth have not much influence on the deterioration rate.


Key wordsFdeterioration rate, design high water level, warm index, maximum snow depth