摘要
从水质改善、营养盐去除、经济投入和经济产出4个方面构建了太湖菱控制性种养工程的环境绩效评估指标体系,并通过环境绩效指数进行综合评估。结果表明,太湖菱控制性种养工程的平均环境绩效指数为-0.60,表明其取得的3项收益(水质改善、营养盐去除和经济产出)之和略小于经济投入。然而,工程具有明显的水质改善效果,与无水生植物的对照水域相比:TN浓度降低50%左右;TP降低20%~76%之间;Chl a降低68%;水体透明度是对照的2倍。红菱同化去除氮磷量为528.30 kg/hm^2,仅约为水葫芦的1/3;以40%毛利率计,在当前的种植模式下,红菱带走1 t氮磷的生态补偿为14万元/t。当前,太湖菱控制性种养工程仍未形成规模化、机械化种植模式,经济投入大、产出低是其最大劣势。借鉴水葫芦种养的成功经验,需要首先扩大种植规模,然后从采收方式机械化以及残体资源化利用两个方面增加经济产出,以提高环境绩效。
An indicator framework was structured to assess projects with confined cultivation of Trapa in Taihu Lake,from four categories including water quality improvement,nutrient removal,economic input and output. The environmental performance index（EPI） was then constructed through the calculation and aggregation of these indicators. The results show that average EPI of the projects is -0.60 which indicates that the benefit of sum of water quality improvement,nutrient removal and economic input is less than economic input. Nevertheless,the projects improve water quality compared with the control areas without aquatic plant,with TN concentration decreased by about 50%,TP decreased by 20% to 76%,Chl a decreased by 68%,and transparency doubled. Nutrient removal by nitrogenous and phosphorus assimilation is 528.30 kg/hm^2 for Trapa which is only one-third of water hyacinth. Accordingly,the ecological compensation standard should be 140 000 RMB for one-ton nutrient removal with 40% gross margin in current cultivation mode of Trapa. Without large-scale and mechanized cultivation,the projects have large investment and low economic output. To increase EPI of these projects in the Lake,proposals are made from successful experiences of water hyacinth cultivation,including increasing cultivated area of per project,and then realizing mechanized harvesting and plant residue recycling.
出处
《环境科学与技术》
CAS
CSCD
北大核心
2016年第12期200-208,共9页
Environmental Science & Technology
基金
江苏省太湖治理科研课题(TH2013316)
关键词
太湖
环境绩效
水生植被
水质改善
Taihu Lake
environmental performance
aquatic vegetation
water quality improvement
