城市河道水环境修复与蚊虫孳生关系及协调性研究

Urban rivers are one of the important habitats of mosquitoes. With the rapid expansion of water environment remediation of urban rivers in China,the distribution of mosquito population densities and community structure could also change, therefore, the risk of mosquito-borne diseases may also increase. This conflict presents a chanllenge to urban river water environment remediation designers and also mosiquito control experts. However, there is no study reports of quantitative correlation or model for prodicting the effects and mechanisms of water quality and remediation technology on mosiquito production at present. Based on this fact, in this project, four urban rivers, named Liwa River and Zhenru River of Shanghai City and West-Shanxia River and Mid-Shanxia River of Wenzhou City will be selected as representative rivers for study. Reseraches including macroscopic investigation, experimental and field studies, monitoring of water environment and mosiquito production, and statistical analysis will be carried out in this project. The assessment between environment and hygiene effectiveness will be also studied based on model configuration and case study. The goal of this project is to optimize the designation,construction operation, and habitats benefits while simutaneously minimizing mosiquito production potential.

城市河道是蚊虫的重要孳生地之一。我国城市河道水环境治理与修复正处于快速发展过程中。城市河道水环境修复的同时也改变了蚊虫孳生的环境，从而对蚊虫的群落结构、种群密度及其时空分布造成影响，进而影响蚊媒疾病风险水平。为此，本课题基于城市河道水环境修复与蚊害防制研究相互脱节的现状问题，以我国东南沿海地区丽娃河大河、真如港东段、山下河中段、山下河西段4条城市河道（段）为代表，通过背景调查、模拟实验与机理研究、现场实证及调控研究，解析城市河道的不同水环境背景及其修复措施与蚊虫孳生的耦联关系及其机制，通过基于环境-卫生协调目标的城市水环境修复评价体系构建及案例分析，评价4条河道（段）的环境-卫生协调性，探索城市河道水环境修复与蚊害防制的协调对策，为实现城市水环境修复与水卫生安全的协调发展提供科学依据。

我国城市河道水环境治理与修复处于快速发展阶段，但其对蚊虫孳生的影响未有系统研究。.水质污染水平对白纹伊蚊和淡色库蚊孵化率、化蛹率及体重影响较大，但对羽化率影响较小。相比较淡色库蚊，白纹伊蚊孳生更倾向于清洁水质。植物引入对蚊虫孳生有抑制和促进双重作用，绿薄荷抑蚊效果较好，其次是鱼腥草和香菇草，而石菖蒲和低密度粉绿狐尾藻则促进了淡色库蚊产卵。植物的影响与其挥发的碳氢化合物及其衍生物有关。枝角类及食蚊鱼对蚊幼的捕杀效率与龄期及数量比有关，当枝角类与I龄蚊幼的数量比由10:10增加至200:10，蚊幼死亡率由13.33%增加至100%，1尾0.8cm食蚊鱼和1尾3cm食蚊鱼对10条I龄蚊幼的半致死时间和全致死时间分别为1.08h及3.38h、3.35h和5.00h。10条河道中有4条河道表现为蚊幼阳性，山下河蚊幼数量最多，其次是工业河、九山外河、桃浦河，主要有4种库蚊和1种伊蚊，淡色库蚊是优势种，其次是致倦库蚊。山下河中发现的白纹伊蚊可能与河面垃圾有关。工业河和桃浦河蚊幼季节消长均为单峰型，高峰期为5～6月，而山下河和九山外河均为双峰型，高峰期为5～6月和10～11月。工作的曝气机附近（＜1.5 m）河面无一蚊幼出现。河道中蚊幼密度与TN、TP、COD及P值和A值呈显著正相关，表明有机碳、氮和磷是蚊幼重要营养源。蚊幼密度与水面遮阳率呈较显著正相关，其次是水面植物盖度。.城市河道水环境修复对蚊虫孳生有着“相容”和“相克”的双重效应，并由此决定两者之间协调度。劣V类黑臭型河道适合于库蚊孳生，当河面垃圾多且植物疏于管理时，会导致库蚊及伊蚊暴发性孳生；河道沿岸绿化宜控制合适乔灌草比例，以便实现成虫和幼虫“双控”目标。北纬27°及以南地区需要关注冬季河道蚊害防制，宜加强河道水面保洁、植物管理并间歇运行曝气机。当河道水质达到Ⅲ类后，可实现河道蚊害防制的生态自维持。.本研究成果是国内外首次报道，对诠释河道蚊虫孳生的生态学机制以及指导蚊害防制实践均具有重要意义和价值。