INNOVATIVE APPROACHES TO ENHANCE WATER QUALITY AND ECOSYSTEM FUNCTION OF CHANNELIZED STREAMS AND DRAINAGE CANALS
作者单位：Professor Extension Associateand Extension AssistantDepartment of Biological and Agricultural EngineeringNorth Carolina State UniversityBox 7625RaleighNC 27695-7625 District Conservation USDA Natural Resources Conservation Service District Technician Currituck Soil and Water Conservation District Albemarle RC ＆ D Coordinator USDA-NRCS Professor Extension Associateand Extension AssistantDepartment of Biological and Agricultural EngineeringNorth Carolina State UniversityBox 7625RaleighNC 27695-7625 Professor Extension Associateand Extension AssistantDepartment of Biological and Agricultural EngineeringNorth Carolina State UniversityBox 7625RaleighNC 27695-7625
会议名称：《第19届国际灌排大会》
会议日期：2005年
学科分类：082802[工学-农业水土工程] 08[工学] 0828[工学-农业工程] 09[农学] 0815[工学-水利工程] 0903[农学-农业资源与环境]
摘 要：正More than 50 percent of fields in eastern North Carolina require improved drainage for efficient production and other land uses. Historically, drainage practices focused on straightening and deepening natural channels to increase their hydraulic capacity and minimize upstream flooding. There are few un-channelized streams remaining in the region. Traditional channel improvements disassociated the channel from the natural floodplain thereby degrading riparian floodplain ecological functions. Intensive drainage systems that are necessary to provide adequate flood protection during wet periods tend to remove more water than necessary during drier periods. However, wetness continues to be a major concern to many landowners. Pilot studies were begun in 1994 to investigate, evaluate, and demonstrate alternative channel design geometries and management to enhance water conservation, water quality, and ecological functions while maintaining the necessary drainage function. Channel alternatives included : establishment of in-stream wetlands, lowering of the floodplain to reconnect the channel with a new floodplain, redesign of channels using natural channel design principles, and establishment of conservation easements to encourage establishment of perennial riparian vegetation. This paper discusses several recent projects that have been implemented to provide better management of drainage water and to restore or enhance ecological functions of large drainage canals. Nitrogen and sediment transport was reduced by 20 to 30 percent on a mass balance basis by incorporation of riparian vegetation and wetland systems within the drainage networks.