基于人工神经网络和粒子群优化的初期雨水调蓄池设计方法研究

Study on design method of the initial rainwater storage tank based on ANN and PSO

城市地表径流所产生的非点源污染是城市水系水质恶化的主要原因,设置初期雨水调蓄池是缓解地表径流污染最经济有效的手段之一。目前,初期雨水调蓄池一般采用经验方法设计,没有考虑汇水区污染物累计特性、污水处理厂处理规模、可用征地等客观条件,初期雨水调蓄池的截污效果有限。本文利用SWMM模型模拟分析了地表径流污染物累积特性,利用人工神经网络得到各调蓄池不同截污率与对应总截污量之间的高精度非线性数学模型;结合该模型,以调蓄池总截污量最大为优化目标,以污水处理厂处理规模和可用征地为约束条件,采用粒子群优化算法得出各调蓄池的优化截污率;结合各调蓄池截污率与径流量累积量之间的关系,得出各调蓄池的设计容积,并与国内常用的设计方法进行对比。分析表明,本文提出方法可在满足约束条件下实现截污效果最大化,采用本文提出方法设计的调蓄池在土地使用率和截污效果上均优于规范设计法。该方法合理、高效和适用范围广,可为城市初期雨水调蓄池设计提供技术支撑。

Non-point Source(NPS)pollution of urban runoff is one of the major causes of water degradation,setting up initial rainwater storage tank is one of the most economical and effective approaches to alleviate the runoff pollution.At present,the initial rainwater storage tank is usually designed by means of the empirical method,which does not consider the factors as the characteristics of pollutant accumulation in catchments,the sewage treatment plants capacity,and the available land etc.,resulting in limited pollutant interception effect.In this paper,the characteristics of accumulated runoff pollutants was simulated by means of SWMM model,and a high-precision nonlinear mathematical model between the pollution interception rates and the corresponding interception runoff volume for the initial rainwater storage tanks was obtained by means of the ANN(Artificial Neural Networks).Combined with the model,the optimal pollution interception rates of the storage tanks was obtained by means of the PSO(Particle Swarm Optimization)algorithm with the maximum pollutant interception amount of the storage tanks under the constraints of sewage treatment plant capacity and the available land.Finally,the volume of the storage tanks was calculated according to the relationship between the pollution interception rate and runoff accumulation.This method was also compared with the empirical design method widely used in China.The results show that the method proposed in this paper could maximize the interception effect of the storage tank under the constraints,and the storage tank designed by this method is superior to that of the empirical design method in terms of land utilization rate and pollution interception effect.This method is reasonable,efficient and widely applicable,which can provide technical support for the design of the initial rainwater storage tank.