水环境研究所

3rd APHW Conference on Wise Water Resources Management Towards Sustainable Growth and Poverty Reduction, 16-18 October 2006, Bangkok , Thailand

Analyses of relationship between eco-discharge and spawning amount of four major Chinese carps in middle reach of Yangtze River

Chong Li 1+ , Jing Peng 2 , Wengen Liao 3 , Baisheng Ye 4

1 Senior Engineer, Department of Water Environment, China Institute of Water Resources and Hydropower Research (IWHR), Beijing , 100038, China

(Tel: 86-10-6858-5792, Fax: 86-10-6857-2778, E-mail: Lichong@iwhr.com)

2 Professor, Department of Water Environment, IWHR, Beijing , 100038, China (E-mail: pengj@iwhr.com)

3 Professor, Department of Water Environment, IWHR, Beijing , 100038, China (E-mail: wgliao@iwhr.com)

4 Professor, Cold and Arid regions Environmental and Engineering Research Institute, Chinese Academy of Sciences, Lanzhou Gansu 730000, China. (E-mail: yebs@ns.lzb.ac.cn)

+ Chong Li: Phn: +86-10-6858-5792, Fax: 86-10-6857-2778, E-mail: Lichong@iwhr.com

Abstract : The four major Chinese carps, black carp (Mylopharyngodon piceus), grass carp (Ctenopharyngodon idellus), silver carp (Hypophthalmichthys molitrix) and big head (Aristichthys mobilis), are main fishes in Yangtze River . Four surveys on the four major Chinese carps have been carried out in 1960s, 1970s, 1980s and 1990s, and their spawning amount data was available in Yidu reach and Jianli reach, which located 40 km and 210 km downstream of Yichang gauge respectively in the middle reach of Yangtze river. Daily discharge from 1900 to 2004 in Yichang gauge was used as referenced discharge for above two-studied reach. Number of discharge rise events, total days with discharge rise (DDS) and average DDS for discharge rise process during May and June were extracted and used to build relationship with spawning amount of the four major Chinese carps during the same period. It was found, there is significant relationship between total DDS and spawning amount in Yidu reach, others relationship is slight. So, the total DDS plays an important role in spawning amount in the middle reach of Yangtze River . The total DDS during May and June does not show significant trend in past 105 years. This implies that the spawning condition on eco-discharge for the four major Chinese carps is not significant altered during past 105 years.

Keywords ： four major Chinese carps, spawning amount, eco-discharge, Yangtze River