浅水草型湖泊生态水文过程演变机制与综合调控

Affected by intense human activities, macrophytic lakes are confronted with a series of problems caused by hydrological regime alteration, such as ecological imbalance and degraded supporting functions to regional economic development etc. In this study, the natural hydrological regime is emphasized for the crucial role in driving and maintaining ecological processes in macrophytic lakes. We aim to address the cumulative effects and regulation issues due to the evolution of multi-scale eco-hydrological processes. The key scientific issue lies on the quantification of the threshold criteria for ecological imbalance and the regulation of multi-objective tradeoff hydrological regime subject to hydrological regime alteration. By identifying the response and feedback mechanism of the biotic population distribution pattern triggered by the habitat variations rising from hydrologic disturbance, we expect to demonstrate the cumulative effects of the evolution of ecohydrological processes in shallow macrophysic lakes, thereby build an ecohydrological evolution dynamic model which couples ecological patterns and processes. The developed model is expected to facilitate the selection of the key indicators for ecosystem stability and resilience in both space and time, and quantify the imbalance mechanism and “tipping point” of lake ecosystems under anthropogenic impact. We aim to further propose a comprehensive hydrological regime regulation framework as well as sustainable water resources management mechanisms which will benefit ecosystem stability and resilience. The outcome of this study is expected to expand ecohydrological evolution theory on shallow macrophytic lakes, propose new thoughts on complex system simulation of lake ecohydrology, and consequently facilitate bridging the gap between emergent environmental flows supplement and sustainable water resources management and integrated regulation.

高强度人类活动影响下，浅水草型湖泊面临水文情势变异引起生态失衡及社会经济支撑功能衰退等系列问题。本项目强调自然水文情势对驱动和维持湖泊生态系统健康的核心作用，针对多尺度生态水文过程演变累积效应和调控研究难点和不足，着重突破水文情势变异条件下的生态失稳阈值及多目标权衡水文情势动态调控机制关键科学问题，揭示水文扰动下生物种群格局分布对生境动态变化响应和反馈机理，阐明浅水草型湖泊生态水文过程演变累积效应，以生态格局－过程耦合关系为核心，构建浅水草型湖泊生态水文过程演变模型，从时、空两个维度提出生态系统稳定性及恢复力控制指标，明确湖泊生态系统失稳机制及突变阈值，提出变化环境下维持生态系统稳定和弹性恢复力的水文情势综合调控模式和长效水资源保障机制。从内涵和机制上丰富湖泊生态水文过程演变理论，为湖泊生态水文复杂系统模型构建提供新思路和新方法，实现应急式生态补水向水文情势综合调控和长效水资源保障转变。

项目紧密围绕国家生态文明发展战略及实现雄安新区蓝绿交织的思想，全面分析了典型浅水湖泊水文情势变化对湖泊生态系统演变的驱动机制，丰富和完善了湖泊生态水文过程演变机理和理论基础；构建了生境格局-过程耦合模型及系统响应突变模型，实现多尺度水文情势扰动下系统稳定性的响应模拟；建立了面向植物多样性保护、湖泊水环境容量提高的生态流量调控方法，提出权衡生态需求和经济效益的生态补水模式，明确了面向生态保护与社会经济协调发展的水资源长效保障机制。发表学术论文84篇(SCI论文63篇)；授权专利6项，出版专著3部，培养博士后2名，博士11名，硕士12名。.（1）浅水草型湖泊生态水文演变模式及其驱动机制：针对高强度人类活动及气候变化综合影响下湖泊自然水文情势的变异驱动生态失衡的重要问题，围绕水文情势变异与生态格局-过程相互作用关系这一关键科学问题，以“水文情势变异—生境格局动态变化—生态系统演变”为研究主线，基于历史数据，分析了白洋淀流域水系格局与水文情势演变过程；在系统分析水文要素变化的基础上，建立了关键水位波动指标-典型生物（浮游植物、底栖动物、水生植物）生境格局的响应关系，探究了典型生物生境格局对水文情势变化的响应机制。.（2）多尺度湖泊生态水文过程演变模型及模拟：针对浅水草型湖泊多时空尺度驱动机制、多要素综合作用复杂性问题，基于浅水草型湖泊中水文过程驱动下的生境格局演变机制，构建了沉水植物、挺水植物、大型底栖动物生境模拟模型。基于元胞自动机和改进的Logistic方程，耦合生境模拟模型和生长动力学模型，构建了挺水植被的格局-过程模拟模型，模拟了不同水文情势下白洋淀芦苇分布格局和生物量，及其耗水量和对水体的净化能力。进一步结合食物网模型，定量模拟和预测了维持生态系统健康的生态需水规律，及不同水文情景下白洋淀草、藻型稳态转换规律及阈值。.（3）变化环境下的水文情势综合调控模式和长效保障机制：在生态水文过程演变研究和格局-过程耦合模型构建的基础上，开展了面向多目标、多尺度需求的水文情势综合调控研究，提出了面向植物多样性保护、湖泊水环境容量提高等多目标的生态流量调控及多水源联合供水优化方法；构建了湖泊二维水动力和水质模型，识别出生态补水后的水力连通过程，预测了不同的生态补水模式下水流路径和营养物质的空间分布，提出了有效的湖泊生态补水模式。