水利工程背景下河流水华暴发成因分析及模拟研究

研究发现，河流水华暴发的主要驱动因素除受过量营养盐摄入、气候变化导致的气温上升和降雨等限制外，水文情势的影响尤为显著.在高强度人类活动影响下，水利工程开发导致的水文情势改变是否为河流水华加剧的成因之一，是水与环境学科交叉研究亟待探索的一个重要应用基础问题.通过对近10年来国内外在水利工程背景下河流水华暴发成因研究进展的综述，辨识了河流水华发生的"水循环-水环境-水生态"相互作用关系；对考虑水文变化的河流水华预测统计学模型、智能算法和水质水量耦合机理模型等进行了回顾和总结，并提出了基于水循环物理过程联系的生物及生物地球化学过程、社会经济用水与管理人文过程等与河流水华发生相互作用与反馈的水系统论研究体系.当前我国水利工程调水影响区下的河流水华问题研究仍面临着一些难点和挑战:① 过去关于水利工程调水对河流中下游水生态的影响研究多数是基于情景假设和规划条件下的预断，随着近年来我国多个大型水利工程的正式实施运行，当前以实际工程调水为背景（如南水北调、引江济汉工程等）开展水华模拟的研究成果仍然十分有限；② 水利工程调水影响区下的河流水华发生机理尚不明确，当前多数藻类生长模型并没有将流域水循环过程影响纳入考虑因素，对河流生态水文过程作用机理与耦合及定量关系分析方面的研究相对匮乏；③ 现阶段水利工程背景下的河流水华问题研究多停留在定性分析和宏观定量阶段，缺乏基于以水系统理论为导向的水生态系统与河流水文情势共同作用机制的定量化研究. 

Research Progress on Cause Analysis and Modeling of River Algal Blooms under Background of Mega Water Projects

Besides excessive input of nutrients, temperature increase and rainfall, change of hydrological regime is regarded as a key driving factor that may cause river algal blooms. However, there is a considerable uncertainty on whether the change of hydrological regime caused by water projects aggravates water blooms in the downstream of river systems. This review collects the existing international and domestic literature from the last ten years in regards to river algal blooms under the background of mega water projects, proposes a relationship among 'hydrology-water quality-water ecology', and proposes future research directions on river water blooms under the impact of water projects. The present study is expected to give theoretical support to address sustainability strategies on regulation of water resources projects. There are still some difficulties and challenges in dealing with river algal blooms under impacts of water projects:(1) The previous researches are mainly based on planned conditions of water transfer projects, so river algal bloom simulations in the actual water transfer conditions are still very limited. (2) The mechanisms of river algal blooms are still not clear, so most current algae models have not considered the effect of water cycle. (3) Most researches on river algae are basically only at qualitative stage; there is lack of quantitative analysis between water ecosystem and water cycle according to water system theory.