围填海活动对黄河口滨海湿地纵向水文连通网络影响

Influence of sea reclamation on coastal wetlands longitudinal hydrological network in the Yellow River Estuary

河口区域的纵向水文连通连接了河流、潮沟,维持着淡咸水交互的滨海湿地格局。为了研究在高强度人类活动背景下黄河口纵向水文连通变化,基于1985-2015年每5年的Landsat遥感影像数据,提取了黄河口河流与潮沟,构建了每个时期的纵向水文连通网络并分析。结果表明,1985-2015年,研究区水系总面积减少了44.07%,水系网络节点和边的数目持续下降。围填海活动侵占黄河三角洲纵向水文连通可分为5种模式,不同模式对纵向水文连通的影响程度不同,在合适的区域采取适当的模式有助于平衡围填海活动与纵向水文连通。通过从图论的角度总结了围填海活动对于纵向水文连通的影响,为研究河口区域人类活动影响提供了新的理论视角,并为实践中采取何种围填海的形式提供指导。

Longitudinal hydrological connectivity of estuary area connects rivers and tidal creeks,maintaining the pattern of freshwater and saltwater interaction in coastal wetland.To study the change of longitudinal hydrological connectivity under high strength human activity,we interpreted rivers and tidal creeks from Landsat images.We constructed longitudinal hydrological networks and analysed them.The result shows that the total area of hydrographic net decreased 44.07%,and the number of network nodes and edges decreased continuously from 1985 to 2015.Sea reclamation’s occupation can be divided into five patterns on hydrographic net,and we found that different patterns influence longitudinal hydrological connectivity in different ways.Choosing suitable patterns in specific areas helps maintaining the balance between sea reclamation activity and longitudinal hydrological connectivity.This paper summaries impacts of reclamation on longitudinal hydrological connectivity from the perspective of graph theory,providing a new theoretical view to study human impacts in estuary region.It also provides a guide in practice of using specific reclamation type.