城市化对湖泊和港湾环境的影响

全球经济的发展必然经历工业化和城市化。在城市化过程中 ,不可避免地产生工业和生活垃圾。这些垃圾不仅污染土地 ,也污染河流和湖泊 ,特别在湖泊和港湾中 ,由于水流速度变缓 ,污染物容易随着沉积物沉淀下来。又由于气候变化和人类活动 ,湖泊和港湾的沉积物会再次释放污染物而污染水体。这些污染物主要是过量的氮、磷、有毒有机物和重金属 ,由于经济和人文环境的不同 ,在不同地区污染程度有差异 ,目前在发展中国家较为严重。针对这些污染 ,人们用机械的、化学的和生物的方法来治理湖泊和港湾的污染 ,但根本上要从源头控制污染———减少污染物的排放

Impacts of urbanization on lake and bay

Wastes are being delivered during human producing and living.The contaminants consist of point and nonpoint sources.They contaminate not only lands,but also rivers and lakes.The pollutants readily deposited with sediments in lakes and bays.Water columns and sediments of lakes are eutrophic and some sediments in bays distribute organic and heavy metal contaminants.The contaminants in sediments will release under the fitful physicochemical condition.The toxic matter is absorbed by some fishes and phytoplankton.They enter into human bodies through food chain.The pollution treatment of developed countries get effective results because of their huge investments and advanced technology.The developing countries can not control their water pollution to a satisfied degree.Besides sewage treatment,we do need to control the pollution sources.