疏浚泥用于滨海湿地生态工程现状及在我国应用潜力

疏浚泥传统的海上倾倒方式现已成为海洋的主要污染来源,而将疏浚泥应用到滨海湿地生态工程具有重要的价值和意义。疏浚泥应用于滨海湿地生态工程在国外的系统研究超过40a,工程运用已有上百年的历史。综述了海洋疏浚泥运用于滨海湿地生态工程的研究前沿和工程运用现状,同时分析其典型的生态工程案例,以期为我国的技术推广提供参考。疏浚泥用于生态工程用途主要有:(1)生态保育下沉和侵蚀性海岸湿地:人为补给疏浚泥可以补偿因高程降低或者海岸侵蚀带来的负面影响,国际上通常采用疏浚泥薄层覆盖法。(2)生态修复受损的滨海湿地:疏浚泥作为基质恢复和重建其潮间带生境,修复因围垦等人类活动严重受损的湿地,从而恢复湿地植被群落;(3)建造人工生态岛:将疏浚泥堆置于便利处,形成自然疏浚泥岛,按照不同的设计高程创造出不同的生境,随着自然的演替,岛屿演替成为生物多样性高和生境丰富的岛屿。以国际上的疏浚泥生态工程运用为借鉴,结合目前我国海洋经济发展的现状和滨海湿地面临的一系列挑战,分析疏浚泥在我国滨海湿地生态重建和生态修复等工程方面的应用前景,为缓解我国海洋产业经济发展和滨海湿地生态环境保护之间的矛盾提供技术借鉴。

Review of the current situation of coastal ecological engineering using dredged marine sediments and prospects for potential application in China

Dredged marine sediments, which are traditionally discarded by open sea disposal, have historically been one of the main marine pollution sources. It is therefore of great value to investigate the beneficial use of these sediments for coastal ecological engineering applications. Recognizing the importance of this beneficial utilization, some countries have been conducting research in this field for up to 40 years. Linked with this, the practice of ecological engineering has a history of more than 100 years worldwide, with demonstration projects distributed along the Atlantic and Pacific coastal zones, and in estuary wetlands. This paper reviews the current research trends and synthesizes engineering application cases worldwide, aiming to provide guidance for dissemination of this technology in China. The main functions of ecological engineering with placement of dredged marine sediments are summarized as follows: (1) Stabilize and nourish subsiding and eroding coastal wetlands. Coastal wetlands in many areas are deteriorating due, in part, to sediment depletion, subsidence and sea level rise. The ecological engineering efforts using dredged marine sediments provide a potential alternative to ameliorate these effects, and to help restore and nourish coastal ecosystems. (2) Restore the deteriorated wetlands. Dredged materials can be used as a substantial substrate to restore the coastal wetlands in formerly diked lands drained for agriculture and other purposes. The potential use of dredged materials includes enhancing the sediment budget at low elevations, reintroduction of tidal effects, and improving the geomorphology of the marsh plant forms. (3) Create artificial ecological islands. Artificial islands may be created with dredged marine materials, and different types of habitats are developed with various elevations to provide nesting and refuge habitats for birds and other wildlife. Historically, many dredged material islands originally created based simply as a convenient placement option have developed naturally into productive and valuable wildlife habitat, supporting abundant biodiversity and various habitats. Based on the accumulated information, which includes the most environmentally sound and technically feasible options for dredged material placement in modern ports and harbors, and taking into account the oceanic industry and the environmental challenges of China, this study discusses the potential applications of dredged marine sediments for coastal engineering. The summarized information from these global experiences provides potential opportunities to combine dredged marine materials treatment with coastal ecological engineering, guaranteeing the sustainable development of the marine industry. The main purpose of this study is to provide an alternative solution to the contradiction between the oceanic economic development and coastal wetlands ecological and environmental protection.