A stochastic model for behaviour of fish ascending an agricultural drainage system |
| |
| Authors: | Koichi Unami Kei Ishida Toshihiko Kawachi Shigeya Maeda Junichiro Takeuchi |
| |
| Institution: | (1) Graduate School of Agriculture, Kyoto University, Kitashirakawa-oiwake-cho, Sakyo-ku, Kyoto 606-8502, Japan |
| |
| Abstract: | Adults of Carassius auratus grandoculis ascend from Lake Biwa, Japan, into riparian paddy fields via agricultural drainage systems for the purpose of spawning. However,
land improvement works conducted in the second half of the twentieth century have brought about obstacles for passage of the
fish, and several restoration projects to recover the migratory environment are being attempted. A continuous Markov process
model is presented to scientifically support such a project, defining an ascending probability that quantitatively assesses
the ability of an agricultural drainage system with hydraulic structures for the ascent of the fish. Computational methods
are developed to numerically obtain flow fields of the agricultural drainage system and then the ascending probability in
the entire spatio-temporal domain. The values of model parameters are deductively inferred, referring to results of field
observations. From the computational results of the ascending probability in the agricultural drainage system, effects of
hydraulic structures allowing ascent of the fish are clarified. |
| |
| Keywords: | |
| 本文献已被 SpringerLink 等数据库收录！ |
|
