| Song Hua River ecological channel Jilin city section project river is located in the main city section of Jilin,is "S" through the city,by the river section of a number of barrage buildings and their own hydrological conditions,the channel infrastructure and other factors,the project river section can not achieve the full line of shipping through,seriously hindered the development of the Song Hua River water traffic.The Heilongjiang River system is included in the national comprehensive three-dimensional transportation system planning for the construction of four horizontal and four vertical water transport network,in order to promote the development of inland navigation on the Songhua River,to meet the demand for water tourism in Jilin City,while improving the ecological environment on both sides of the Songhua River,to create an ecological tourism channel with special features,Jilin intends to carry out the channel improvement project in this section of the river.The Jilin section of the Songhua River is a protected area for the endemic fish,the seven-gill eel.In order to promote the synergy between the development of the Songhua River navigation and ecological environmental protection,this waterway project is intended to carry out the construction of fish habitat creation program simultaneously.The paper constructs a model for evaluating the suitability of the waterway project and the habitat suitability of the seven-gill eel in the section of the Songhua River from the rubber dam to the Longtan Bridge,calculates and analyzes the changes in water depth,flow velocity,water level,specific drop and other navigational indicators in the study section before and after the implementation of the waterway improvement project and their effects on the habitat of the seven-gill eel,and proposes a site selection area for habitat creation to protect the fish in the study section.The optimal habitat creation plan was selected from the perspectives of habitat creation effect,engineering volume and navigability.The main contents and results of the paper are as follows:(1)To establish a two-dimensional water flow mathematical model from the rubber dam to Longtan Bridge and verify the accuracy of the model.The habitat factors(water depth and flow velocity)were determined,and the habitat suitability curves of seven-gill eels were drawn from the literature to construct a habitat suitability evaluation model.Mainly introduce the findings on hydrology of the project river section,characteristics and distribution of protected fish,composition of geomorphological units and division of habitat functional units;(2)The model calculations of the study river section before the channel project were carried out,and the changes in the hydraulic characteristics of the study river section before and after the channel project were obtained based on the calculation results,and the changes in the habitat suitability of the river section were analyzed in conjunction with the suitability evaluation model,and finally the adverse effects on the suitability of the study river section where the seven-gill eel was located after the construction of the channel project were summarized and analyzed.The effects of the waterway project and its impact on the habitat are presented.(3)Based on the impact on the habitat of the seven-gill eel and the minimization of the impact of habitat creation on the navigation of the channel,the site for habitat creation was selected on the right bank from 52.6 km to 52.27 km downstream of the rubber dam,and a combination of submerged dam and excavation was used to create the habitat.The optimal solution was determined from the perspective of creation effect and economic efficiency.At the same time,the model data were analyzed to determine that the optimal solution would not adversely affect the navigability of the channel.The layout and demonstration of habitat creation options,the effect of each habitat option after implementation and the recommendation of the option are presented. |
