面向生态环境的河湖连通引水调控方案研究

Study on the water diversion regulation scheme of interconnected river system network oriented to ecological environment

河湖水系连通是解决湖泊水环境和水生态问题的重要手段,但如何确定合理的引水调控模式是目前开展河湖连通工作中面临的重点和难点问题。以汤逊湖水系连通工程为研究对象,建立二维浅水湖泊水动力水质数学模型,分析5种引水流量工况下汤逊湖的NH3-N、TN和TP水环境改善效果,根据改进的成本效益评估法对不同引水方案的环境效益进行评估,由此确定最佳的引水调控方案。研究结果表明:引水后汤逊湖水质得到明显改善,且引水流量越大,汤逊湖的水质浓度改善率越大,超标水体比例越少;随着引水流量的增加,净效益先增大后减小,引水流量为40 m^3/s时河湖连通能够带来最大的引水效益。本研究可为汤逊湖及其他类似水域河湖水系连通方案的选择提供科学的参考依据。

The interconnected river system network(IRSN)is an effective means to solve the problems of lake water environment and water ecology.However,how to determine a reasonable water diversion scheme is the key and difficult issue in the implementation of the IRSN.The Tangxun Lake water system was selected as the research object,and a two-dimensional(2-D)mathematical hydrodynamics and water quality model of shallow water lakes was built.Water environment improvement effects of NH3-N,TN and TP in the Tangxun Lake of five water diversion schemes were simulated,and the environmental benefits of different water diversion schemes were evaluated according to the improved cost-benefit assessment approach,so as to determine the optimal water diversion and regulation scheme.Results showed that the water quality of the Tangxun Lake was significantly improved after the water diversion,and the larger the diversion flow,the greater the water quality improvement rates,and the less the proportion of substandard water bodies.With the increase of water diversion flow,the net benefit first increased and then decreased.The water diversion flow of 40 m3/s brought the greatest economic benefits.This study can provide scientific reference for the scheme selection of IRSN of Tangxun Lake and other similar projects.