Evaluation of suitable hydraulic conditions for spawning of ayu with horizontal 2D numerical simulation and PHABSIM

Takayuki Nagaya, Yoshiki Shiraishi, Kouki Onitsuka, Makoto Higashino, Tohru Takami, Noriharu Otsuka, Juichiro Akiyama and Hiroaki Ozeki

Ecological Modelling, 2008, vol. 215, issue 1, 133-143

Abstract: Hydraulic structures such as a dam, weir and water gate affect on the flow depth, velocity, bed topology, water quality and so on, so that the hydraulic structures may affect on the water environment for plants and aquatic lives in and around rivers. Therefore, before construction of such hydraulic structures, it is necessary to conduct the environmental assessment. However, the accuracy of the environmental assessment is not so high at present, because the preference curves of the flow depth, velocity and so on are not clear. Recently, Nagaya et al. [Nagaya, T., Onitsuka, K., Higashino, M., Takami, T., Otsuka, N., Akiyama, J., Matsumoto, K., 2004. Evaluation of weight of parameter for spawning of ayu, Plecoglossus altivelis, and prediction of spawn density per unit area. In: Lee, J.H.W., Lam, K.M. (Eds.), Environmental Hydraulics and Sustainable Water Management, vol. 2. AA. Balkema Publishers, UK, pp. 947–954] pointed out that the velocity, flow depth and substrate affect on the suitability of spawning for ayu, Plecoglosses altivelis altivelis on the basis of statistical investigation. Preference curves of velocity and flow depth were made clear by Onitsuka et al. [Onitsuka, K., Nagaya, T., Higashino, M., Takami, T., Otsuka, N., Akiyama, J., Ozeki, H., Matsumoto, K., Shiraishi, Y., 2005. Suitable flow depth and velocity for spawning of ayu, Plecoglossus altivelis. In: Proceedings of the 31th Congress of IAHR, Korea, pp. 1850–1858]. On the other hand, the preference curve of substrate has not been investigated. In this study, the preference curve of substrate was investigated on the basis of field survey. Further, a numerical simulation by making use of a horizontal 2D numerical model was carried out with changing the discharge at the Gokasegawa River due to a lot of ayu inhabits in the Gokasegawa River. The numerical model is based on the model which was suggested by Nagata et al. [Nagata, N., Hosoda, T., Muramoto, Y., 2000. Numerical analysis of river channel processes with bank erosion. Journal of Hydraulic Engineering, ASCE 126 (4), 243–252]. The suitability of spawning for ayu is predicted with the preference curves of the flow depth, velocity and substrate.

Keywords: Ayu; Spawning; PHABSIM; Suitability index; 2D numerical simulation (search for similar items in EconPapers)
Date: 2008
References: View complete reference list from CitEc
Citations: View citations in EconPapers (6)

Downloads: (external link)
http://www.sciencedirect.com/science/article/pii/S0304380008000860
Full text for ScienceDirect subscribers only

Related works:
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: https://EconPapers.repec.org/RePEc:eee:ecomod:v:215:y:2008:i:1:p:133-143

DOI: 10.1016/j.ecolmodel.2008.02.043

Access Statistics for this article

Ecological Modelling is currently edited by Brian D. Fath

More articles in Ecological Modelling from Elsevier
Bibliographic data for series maintained by Catherine Liu ().