城市湖库蓝藻水华形成机理综合建模研究

蓝藻水华形成是诸多营养及环境因素相互作用的结果,因此,本文对城市湖库蓝藻水华形成(包括复苏、萌芽、生长、暴发阶段)这一复杂生态过程进行了综合建模研究.通过在阳光房中模拟湖库蓝藻水华形成过程,采用正交实验分析获得蓝藻生长的关键影响因素,并为蓝藻水华形成机理建模提供相应参量.在此基础上,构建了用于模拟湖库蓝藻水华形成过程的蓝藻生长机理模型,采用遗传算法对机理模型中涉及的参数进行优化率定;同时,考虑蓝藻水华暴发阶段具有突变特性,建立了描述蓝藻水华暴发状态的尖点突变模型,进而构建了城市湖库蓝藻水华形成各阶段的综合机理模型.实验仿真结果表明,该综合机理模型能较好地模拟城市湖库蓝藻从复苏到暴发整个过程的变化规律,且该模型结合了数学机理建模和智能方法的优势,克服了单一蓝藻水华机理模型的缺陷,为湖库蓝藻水华形成机理的深入研究提供了新思路.

Comprehensive mechanism modeling on city lake cyanobacteria bloom formation

We developed comprehensive mechanism modeling on city lake cyanobacteria bloom formation, a complex ecological process (including recovery, germination, growth and outbreak) caused by the interaction of various nutrient and environmental factors. Through lake cyanobacteria bloom formation process simulation in the sunroom laboratory, the key factors of cyanobacteria growth were obtained by the orthogonal test to provide parameters for cyanobacteria bloom mechanism modeling. Cyanobacteria growth mechanism model was subsequently developed for simulating the formation of cyanobacteria bloom, with involved parameters optimized by genetic algorithm. Considering the mutation during cyanobacteria bloom outbreak, the cusp catastrophe model was established to describe the outbreak state of cyanobacteria bloom. In addition, the comprehensive mechanism analysis model demonstrated various stages of lake cyanobacteria bloom formation. Experimental findings provided evidences that the changing regularity of algae ranging from recovery to outbreak stages can be simulated by means of the comprehensive mechanism model, which combined the optimization of math mechanism modeling with intelligent method. The combination overcame defects of single cyanobacteria bloom mechanism models and contributed to a new perspective of further exploring cyanobacteria bloom formation in lakes and reservoirs.