流域河口湿地生态健康与湿地发育关系研究

The relationship between estuary wetland ecological health and river geographical development

河口湿地作为一个独立的"活体",有着其自身的地理发育、成熟和衰老的生长过程。以大洋河河口湿地为例,运用面积积分曲线和分维度指数计算大洋河流域发育阶段及河口湿地生长过程,得出如下结论,(1)在河流流域地貌发育早期,河流底蚀、侧蚀、溯源侵蚀强烈,河流含沙量高,泥沙在河口地区沉降而易形成河口湿地;随着流域地貌发育到壮年期,河流泥沙含量输出稳定,河口湿地面积继续扩张;到流域地貌发育晚期,侵蚀减弱,河流含沙量减少,河口湿地缺乏稳定的泥沙供应,在河湾水动力作用下逐渐萎缩、直至消亡。(2)人类活动直接影响河口湿地环境的物理、化学和生物组份,改变了河口泥沙的输入量及沉积环境,人类活动实际上是直接或间接地缩短了河口湿地的发育时间,加速了其发育进程。(3)针对不同发育阶段的河流,在制定河口湿地保护政策和修复措施时,必须充分考虑其地质历史发育特征,政策的制定要符合其生长规律。

the estuarine wetland has its own geographical development,as a separate ＂live＂.In this article,using the area integral curves and fractal dimension index,Calculating the DaYang river basin development stage and estuarine wetland growth process and obtaining the following conclusions：（1） The early developmental stages of river basin topography,river erosion（consist of river end of erosion,lateral erosion and headward erosion） is strong,river sediment concentration is high,and sediment settlement in the estuary area is easy to form estuarine wetlands.Along with the watershed geomorphic development into the mature stage,the river sediment output is stability,estuarine wetland area continues to expand;In the later stages of basin landform development,erosion is weak and river sediment concentration reduced.The estuarine wetland gradually shrinks until the demise in the bend of the river hydrodynamic effect.（2） human activity not only impacts directly on the estuarine wetlands of physical,chemical and biological components,but changes input and depositional environment of the estuarine sediment.Human activities directly or indirectly,actually shorten the development of estuarine wetlands,accelerated river estuary wetland development process.（3） The protection policies and restoration measures must take full account of the characteristics of the geological history and development in the different developmental stages of the river estuarine wetland.Policy formulation must be fit for the growth law.