洞庭湖退耕还湖区水质监测与分析

Supervision and Analysis of Water Quality in Dongting Lake Recovery Area

选择洞庭湖退耕还湖区汉寿县青山湖垸不同生境条件区及周边地区对照点,3年水质监测表明,围垦区在退耕还湖后的前1～2年,水体中氮、磷营养元素,化学耗氧量,生化耗氧量,大肠菌群等项水质指标比本区河流、湖泊天然水体含量高,水体有轻度富营养化现象,但较目前堤垸区地面水水质要好,且其富营养化程度依老宅基区、老堤垸区、老稻田区、老林地草滩区和老渔塘区而依次减弱。随着退耕还湖后多次淹水、退水的进行,退耕还湖区各项水质指标正逐步接近天然水体,这标志着洞庭湖退耕还湖区湿地生态系统的恢复、重建正在缓慢进行。

Supervision of water samples of 3 years in different habitat area and corresponding sites in Dongting Lake recovery area, indicates that N、P、COD、BOD and Coliforms of water are higher in quantity than those of natural rivers and lakes . The water of restoration area is of slights eutrophication, but better than surface water in dike yards. The degree of water eutrophication of old yards, old dike yards, rice fields, woodland, grassland and fishery is in order. With lake recovery, flood rising and falling, each water quality index is close to that of natural water, this marks that the resumption and reconstruction of wetland ecosystem is in gradually underway.