我国道路工程湿地生态影响评价——以东北地区公路项目为例

Ecological Impact Assessment of Road Construction in Wetland of China——A Case Study of Highway Projects in Northeastern Area

为提高道路工程湿地生态影响评价的科学性和有效性,推动湿地保护工作,选取2006—2015年环境保护部审批和验收的东北地区公路项目为案例,基于环境影响评价和验收调查文件等资料,从湿地生态调查和评价的内容、方法、减缓措施以及运营期环境管理等方面,剖析了当前道路工程湿地生态影响评价现状及存在的主要问题,主要包括:(1)湿地水文情况调查不足,水文特征相关指标变化趋势的分析内容缺失;(2)在改扩建公路项目或与既有公路、铁路并行、交叉的新建项目中,既有工程对湿地的影响未得到系统的评估;(3)湿地生态系统本身的复杂性、遥感解译人员对湿地类型的理解差异以及影像分辨率高低差异,造成对湿地识别不足和湿地相关信息缺失或遗漏;(4)未从湿地保护的角度对工程通过形式开展充分论证,造成桥涵设计不合理;(5)未在运营期开展生态监测和环境影响后评价。针对道路工程湿地生态影响评价存在问题,应从技术和管理层面尽快开展相关工作。一是研究构建适用于道路工程湿地生态影响评价的指标体系;二是以提高湿地数据的精确度为目标研究并改进湿地遥感信息提取的技术方法;三是通过规划环评和早期介入,从源头控制湿地退化、丧失和破碎化;四是实施运营期生态监测和后评价,评估实际影响并提出相应的道路工程改造和湿地修复方案。

To promote the scientificity and effectiveness in ecological impact assessment of road construction on wetlands,and to advance wetland conservation,the highway projects in Northeastern China approved and examined by Ministry of Environmental Protection during 2006—2015 are selected for case study. Based on the environmental impact assessment and acceptance checking reports of these projects,the present situation of ecological impact assessment of road construction on wetlands and the main problems,in terms of contents,methods,mitigation measures and environmental management during the operation period of wetland ecological investigation and assessment,are analysed. The existing problems including（ 1） the hydrological regimes of wetlands are inadequately surveyed and the dynamics of hydrological indexes are absent;（ 2） the impacts of existing road construction on wetlands are not systematically evaluated, especially for road expansion projects or new roads that parallel or cross with the existing roads and railways;（ 3） incompleteidentification of wetlands and deficiency or omission of related information caused by the complexity of wetland ecosystems,difference in the interpretation of wetland types by remote sensing interpreters and difference in image resolution;（ 4） unreasonable design of bridges and culverts caused by the inadequate reasoning of different structure schemes of road from the prospective of wetland protection; and（ 5） ecological monitoring and environmental impact post assessment are not implemented during the operation period. To remedy these problems, further works should be carried out as soon as possible from technical and management aspects,such as（ 1） explore and establish the index system which is applicable to ecological impact assessment of road construction on wetlands;（ 2） study and improve the extraction technology and method of remote sensing information on wetlands,aiming to enhance the accuracy of wetland data;（ 3）mitigate the degradation,loss and fragmentation of wetlands from the source by means of involving in road planning and environmental impact assessment earlier,and（ 4） implement the ecological monitoring and post evaluation during the operation period, assess the actual impact to propose the corresponding road reconstruction and wetland restoration scheme.