淀山湖水质及与环湖稻田农业面源污染的关系

对淀山湖主要进水和出水口水质进行年度定点监测; 同时, 布置田间试验, 研究不同施肥稻田田面水养分含量动态. 结果表明:淀山湖进出水口水体氨氮和总磷年平均质量浓度分别为 0.47 和 0.13 mg/L, 基本处于 Ⅴ 类水质标准; 进水口水质略劣于出水口, 不同进水口的水质也有很大差异. 进一步研究发现, 淀山湖水质的年度变化与稻田田面水养分的动态变化有密切的相关性, 表明农业面源污染对淀山湖水环境具有显著影响. 在环湖地区, 减少和控制农业面源, 是进一步改善淀山湖水环境质量的关键.

Water quality of Dianshan Lake and its correlations with diffuse agricultural pollution from rice fields

The water quality of the inlets and outlets of Dianshan Lake was monitored annually. Likewise, a field experiment was conducted near Dianshan Lake to study the variations of nutrients in the surface water of experimental plots for various fertilizer treatments. The results indicated that the average contents of NH$_{3}$-Nandtotal P (TP) of the water in Dianshan Lake were 0.47 and 0.13 mg/L, respectively, which only met the Class Ⅴ level specified by the China Surface Water Environmental Quality Standard. The water quality of the inlets of Dianshan Lake varied from site to site and was generally worse than the water quality of the outlets. Further study found close correlations between the annual variations of nutrients in Dianshan Lake and the variations in the surface water of the rice fields. This suggests that the water quality of the lake was strongly influenced by diffuse agricultural pollution from the rice fields surrounding the lake. Therefore, to improve the water quality of Dianshan Lake further, it is highly important to reduce and control the diffuse agricultural pollution.