历史时期黄河下游安山湖湿地演变及其与黄河-运河关系的研究

A number of lakes and wetlands were present in the low-lying floodplain of the lower Yellow River during the historical period, which has played a vital role in regulating the flood of the Yellow River, maintaining ecosystem service, and improving local climate conditions. In the meanwhile, the ecosystem and hydrological conditions of these water bodies were greatly influenced by the repeated flooding of the Yellow River and the navigation of the Grand Canal, giving rise to several to tens of meters of lacustrine deposits and thereby making it an ideal site for studying the evolution mechanism of the lake-wetland system and its relationship with the Yellow River and the Grand Canal. In this proposed project, we aim at obtaining a continuous sediment core from the Anshan Lake, establish an accurate chronological framework through AMS-14C and OSL dating methods, and conduct multi-proxy analyses such as sedimentology, geochemistry, and diatoms. Also, we strive to investigate the shoreline position of the Anshan Lake-wetland during different stages, and combine sedimentology and GIS methods to determine the size and storage capacity of the Anshan Lake-wetland complex during the corresponding phase. The overarching objectives of this project were to better understand its formation and evolution and the driving mechanism; capture the flooding events of the Yellow River in the drainage basin, and to reveal the relationship between the lake-wetland system and the Yellow River. Based on integrated analyses of historical documents and the characteristics of environmental proxy records, we also intend to ascertain the relationship between the Beijing-Hangzhou Grand Canal and the Anshan Lake-wetland system This work will provide consulting information for the stakeholder about the restoration and green detention of the lake-wetland system in the lower Yellow River area as well as the feasibility of revitalizing the navigational functionality of the Beijing-Hangzhou Grand Canal.

历史时期黄河下游平原地区发育了众多湖泊和湿地。它们在调蓄黄河洪水、涵养水源、改善局地气候等方面发挥了重要作用。同时，这些水体的生态环境和水文状况深受黄河频繁泛滥和运河航运的影响，堆积了数米至几十米的湖相地层，是研究该区湿地演化规律及其与黄河洪水、运河航运关系的极佳场所。本项目拟以安山湖钻孔为研究对象，通过AMS-14C和光释光测年建立高精度的年代序列，系统开展沉积学、地球化学、硅藻学等环境指标的研究，并且根据探槽揭示的泥炭层位，通过沉积学、GIS等方法综合分析，确定安山湖不同演化阶段（一般期、极盛期、衰落期）的岸线位置、湖泊湿地规模和库容；阐明安山湖湿地演化过程和机理；捕获流域极端洪水事件信息，揭示黄河洪水对安山湖演变的影响；探讨运河通航方式与安山湖之间的关系，特别是安山湖“水柜”对运河连续通航的作用。这对研究黄河下游湿地修复、绿色蓄洪以及运河复航的可行性等方面具有重要的理论和实际意义。

历史时期黄河下游地区发育了众多湖泊和湿地，其中安山湖是非常重要的一个湿地，其形成演化深受黄河泛滥改道的影响。作为运河水柜，其在保障运河行运通航方面具有重要意义。本课题以湖泊沉积物和洪泛地层为研究材料，围绕安山湖湿地演化规律及其与黄河、运河关系问题进行了深入研究。项目重点开展了黄河下游地区湖泊群（安山湖、梁山泊、大野泽）和堌堆遗址（菏泽十里堡）的取样和分析工作。通过黄河下游湖泊群钻孔分析，结果表明黄河下游湖泊群的变迁与黄河关系十分密切，表现出河水注入、湖面扩大，河徙水退、湖面萎缩的复杂过程；黄河洪水注入导致湖泊湿地扩张，梁山泊和大野泽在940-1250AD期间达到最高湖水位；安山湖湿地由大野泽、梁山泊演化而来，约在公元1215年，大野泽受黄河第四次改道影响，向北演化为梁山泊；约在公元1470年，梁山泊受到黄河第五次大改道影响，向北演化为安山湖；安山湖湿地变迁与黄河、运河关系密切，黄河为安山湖、运河提供了水源，在运河通航过程中发挥着重要作用，同时黄河泥沙淤积河道和湖泊湿地也是运河通航的“瓶颈”问题；通过对十里堡考古遗址地层分析，辨识了新石器-青铜器转型期黄河下游地区的两次大洪水，可能与全球变冷背景下持续减弱的厄尔尼诺有关，大洪水改变了黄河下游地区的地表和水文景观，影响了早期国家的起源。研究结果对黄河下游湿地修复、绿色蓄洪以及运河复航等具有重要科学参考价值。