Ecological flow process acknowledging different spawning patterns in the Songhua River

Abstract

Based on the complex population structure of fish species in Songhua River, this paper broke through the present method modeling by the single target species and introduced a developed approach classified by different spawning habits to evaluate ecological flow. Three main spawning periods and two spawning types were respectively analyzed combining with biographical information. For the characteristic of abundant branching channel and wide floodplain in study area, MIKE21 hydrodynamic model was applied to simulate hydrological condition. Combing the habitat preference curves and hydrodynamic results, the composite suitability index for the study reach was attained. At the same time, the lasting time of fish incubation was used to suggest the flow duration. At last, this paper put forward the optimal discharge, flow duration, occurrence time and frequency in April, May and June-July respectively. Using this result, the ecological flow process can effectively support to the management strategies for rational allocation of water resources.