[Objective] The research aimed to reduce emission load of the farmland runoff by using ecological ditches and pond. [Method] N and P intercepting project construction of the ecological ditches and pond in Zhaiji Villa...[Objective] The research aimed to reduce emission load of the farmland runoff by using ecological ditches and pond. [Method] N and P intercepting project construction of the ecological ditches and pond in Zhaiji Village, Xiangcheng District, Suzhou City as research object, by repairing 1 834 m3 of original drainage ditches, newly excavating 6 800 m2 of ecological main ditches and 6 000 m2 of artificial purification ecological pond, etc., runoff emission load in real control area of the project was counted. [Result] Annual net loads of the runoff emission for TN and TP were respectively 2 552.22 and 95.00 kg in 33.3 hm2 of farmland. Annual runoff intercepting loads of TN and TP were respectively 1 225.07 and 50.35 kg in ditches. Annual runoff intercepting loads of TN and TP were respectively 1 327.15 and 44.65 kg in ecological pond. In effluent, TN concentration was 6.32 mg/L and was smaller than 15 mg/L. TP concentration was 0.25 mg/L and was smaller than 0.5 mg/L. They both reached level-one A discharge standard. [Conclusion] The research provided theoretical basis for effective control of the agricultural non-point source pollution in Taihu Lake basin.展开更多
In the Niheishimizu and Ooshimizu sections of the town of Misato in the Akita Prefecture, Northern Japan, there are many abundant spring water areas. Sparganium (Sparganium emersum and Sparganium erectum) species are ...In the Niheishimizu and Ooshimizu sections of the town of Misato in the Akita Prefecture, Northern Japan, there are many abundant spring water areas. Sparganium (Sparganium emersum and Sparganium erectum) species are widely distributed in the irrigation water that fed by spring water. The irrigation waters were divided the natural type ditch and the maintained ditch that connect with nearby natural ditch to promote environmentally friendly agriculture. This study was conducted in both sections to support the maintenance of the irrigation water fed by the abundant spring water. A vegetation survey was conducted in September of 2005. The survey collected data on the amount of vegetation cover and the stem lengths of the plant species found in selected locations of the study area. The water depths and the flow velocities were also measured in these locations. As for the growth situation of S. emersum and S. erectum, the submerged form of S. emersum was found in water approximately 15 cm deep with a surface flow velocity of approximately 7 cm/s. This species was characterised by a relatively fast flow and relatively shallow water. The emergent and submerged growth forms of S. emersum were found in waters having flow velocities faster than those associated with S. erectum. The emergent form of S. emersum grew in relatively deep water. S. emersum is more capable of adjusting to the conditions of stream habitats than S. erectum.展开更多
基金Supported by Provincial Special Fund,Comprehensive Treatment of the Water Environment(Phase V)in Taihu Lake,China[xiangfagaitou(2011)27]
文摘[Objective] The research aimed to reduce emission load of the farmland runoff by using ecological ditches and pond. [Method] N and P intercepting project construction of the ecological ditches and pond in Zhaiji Village, Xiangcheng District, Suzhou City as research object, by repairing 1 834 m3 of original drainage ditches, newly excavating 6 800 m2 of ecological main ditches and 6 000 m2 of artificial purification ecological pond, etc., runoff emission load in real control area of the project was counted. [Result] Annual net loads of the runoff emission for TN and TP were respectively 2 552.22 and 95.00 kg in 33.3 hm2 of farmland. Annual runoff intercepting loads of TN and TP were respectively 1 225.07 and 50.35 kg in ditches. Annual runoff intercepting loads of TN and TP were respectively 1 327.15 and 44.65 kg in ecological pond. In effluent, TN concentration was 6.32 mg/L and was smaller than 15 mg/L. TP concentration was 0.25 mg/L and was smaller than 0.5 mg/L. They both reached level-one A discharge standard. [Conclusion] The research provided theoretical basis for effective control of the agricultural non-point source pollution in Taihu Lake basin.
文摘In the Niheishimizu and Ooshimizu sections of the town of Misato in the Akita Prefecture, Northern Japan, there are many abundant spring water areas. Sparganium (Sparganium emersum and Sparganium erectum) species are widely distributed in the irrigation water that fed by spring water. The irrigation waters were divided the natural type ditch and the maintained ditch that connect with nearby natural ditch to promote environmentally friendly agriculture. This study was conducted in both sections to support the maintenance of the irrigation water fed by the abundant spring water. A vegetation survey was conducted in September of 2005. The survey collected data on the amount of vegetation cover and the stem lengths of the plant species found in selected locations of the study area. The water depths and the flow velocities were also measured in these locations. As for the growth situation of S. emersum and S. erectum, the submerged form of S. emersum was found in water approximately 15 cm deep with a surface flow velocity of approximately 7 cm/s. This species was characterised by a relatively fast flow and relatively shallow water. The emergent and submerged growth forms of S. emersum were found in waters having flow velocities faster than those associated with S. erectum. The emergent form of S. emersum grew in relatively deep water. S. emersum is more capable of adjusting to the conditions of stream habitats than S. erectum.
