[Objection] The aim was to study application of channels constructed wetland in treatment of domestic sewages in new countryside. [Method] Supported by construction of new rural areas project in China, we surveyed on ...[Objection] The aim was to study application of channels constructed wetland in treatment of domestic sewages in new countryside. [Method] Supported by construction of new rural areas project in China, we surveyed on new rural areas in Gannan, Jiangxi Province, summarized source, characteristics and treatment of domestic sewage in countryside, and designed channels constructed wetland for sewage treatment. [Result] The technique is proven effective in sewage treatment. After the technique was conducted for a trial run for four months, removal rates of COD, TP and TN averaged 73.07%, 73.25% and 72.36%, respectively. After contin- uous sampling for six times, effluent COD was analyzed 20-35 mg/L, TP was 0.60- 1.19 mg/L and TN was 6.88-11.21 mg/L, better than that of Standard 1B ruled by Discharge Standard of Pollutants for Municipal Wastewater Treatment Plant. [Conclusion] Thanks for low investment, channels constructed wetland can be built by trans- formation of bottom land, proving a good way for treatment of diffuse pollution source and control of water non-point pollution.展开更多
Both interchannel wetlands and multi-channels are crucial geomorphologic units in an anastomosing river system. Planform characteristics and development of interchannel wetlands and multi-channels control the characte...Both interchannel wetlands and multi-channels are crucial geomorphologic units in an anastomosing river system. Planform characteristics and development of interchannel wetlands and multi-channels control the characteristics of anastomosing rivers. To under- stand the role that interchannel wetlands play in the development of anastomosing rivers, a study was conducted on the Maqu Reach of the Upper Yellow River （MRUYR）, a gravel-bed anastomosing river characterized by highly developed interchannel wetlands and ana- branches. Geomorphologic units in the studied reach were extracted from high resolution satellite imagery in Google Earth. The size distributions of interchannel wetlands and inter- channel wetland clusters （IWCs）, a special combination of interchannel wetlands and ana- branches, were investigated. Geomorphologic parameters, including the ratio of interchannel wetland area to IWC area （P）, shoreline density （DL）, and node density （Dn） were used to analyze planform characteristics of IWCs and the development of multi-channels in the stud- ied reach. The results suggest that small or middle sized interchannel wetlands and large or mega sized IWCs are more common at the study site. The area of IWC （Su） is highly cor- related with other geomorphologic parameters. P increases with increasing Su, and the upper limit is about 80%, which indicates that the development of interchannel wetlands and ana- branches in the IWC is in the equilibrium stage. In contrast, D~ and D, show a tendency to decrease with increasing Su due to diverse evolution processes in IWCs with different sizes. There are three main reasons leading to the formation of IWCs： varying stream power due to the meandering principal channel; development of the river corridor due to the weakening of geologic structure control; and high stability of interchannel wetlands due to conservation by shoreline vegetation.展开更多
In the past decades, two large scale coastal engineering projects have been carried out in the Deep Bay surrounded by Shenzhen City and Hong Kong Special Administrative Region. One project is Shenzhen River channel re...In the past decades, two large scale coastal engineering projects have been carried out in the Deep Bay surrounded by Shenzhen City and Hong Kong Special Administrative Region. One project is Shenzhen River channel regulation and the other is the sea reclamation along the seashore on the Shenzhen side. The two projects are very close to the two national nature reserves, specifically Futian in Shenzhen and Mai Po in Hong Kong, which are important wetland ecosystems worldwide. This paper aims to identify and monitor the mangrove wetland changes with time series of Landsat Thematic Mapper images pre and post to the two engineering projects being launched. Coupled analysis of the image interpretation results and tidal data acquired at the same time in the context of the two works reveals that the mangrove wetland area has increased from year 1989 to 1994, and has changed little from year 1994 to 2002. Binary coding is applied to reveal the distribution image of mangrove at each phase, and the coding image shows that the construction of the two coastal engineering projects has caused frequent changes in mangrove spatial distribution. The study also shows that the change is not significant regarding to the precision of the method and the natural evolution of mangrove wetland, and the projects do not cause apparently influences upon the two national mangrove conservation zones at least for the research time period.展开更多
基金Supported by Project of the National Eleventh-Five Year Research Program of China(2008BAD96B04)~~
文摘[Objection] The aim was to study application of channels constructed wetland in treatment of domestic sewages in new countryside. [Method] Supported by construction of new rural areas project in China, we surveyed on new rural areas in Gannan, Jiangxi Province, summarized source, characteristics and treatment of domestic sewage in countryside, and designed channels constructed wetland for sewage treatment. [Result] The technique is proven effective in sewage treatment. After the technique was conducted for a trial run for four months, removal rates of COD, TP and TN averaged 73.07%, 73.25% and 72.36%, respectively. After contin- uous sampling for six times, effluent COD was analyzed 20-35 mg/L, TP was 0.60- 1.19 mg/L and TN was 6.88-11.21 mg/L, better than that of Standard 1B ruled by Discharge Standard of Pollutants for Municipal Wastewater Treatment Plant. [Conclusion] Thanks for low investment, channels constructed wetland can be built by trans- formation of bottom land, proving a good way for treatment of diffuse pollution source and control of water non-point pollution.
基金Foundation： National Natural Science Foundation of China, No.41571005, No.4 1271027
文摘Both interchannel wetlands and multi-channels are crucial geomorphologic units in an anastomosing river system. Planform characteristics and development of interchannel wetlands and multi-channels control the characteristics of anastomosing rivers. To under- stand the role that interchannel wetlands play in the development of anastomosing rivers, a study was conducted on the Maqu Reach of the Upper Yellow River （MRUYR）, a gravel-bed anastomosing river characterized by highly developed interchannel wetlands and ana- branches. Geomorphologic units in the studied reach were extracted from high resolution satellite imagery in Google Earth. The size distributions of interchannel wetlands and inter- channel wetland clusters （IWCs）, a special combination of interchannel wetlands and ana- branches, were investigated. Geomorphologic parameters, including the ratio of interchannel wetland area to IWC area （P）, shoreline density （DL）, and node density （Dn） were used to analyze planform characteristics of IWCs and the development of multi-channels in the stud- ied reach. The results suggest that small or middle sized interchannel wetlands and large or mega sized IWCs are more common at the study site. The area of IWC （Su） is highly cor- related with other geomorphologic parameters. P increases with increasing Su, and the upper limit is about 80%, which indicates that the development of interchannel wetlands and ana- branches in the IWC is in the equilibrium stage. In contrast, D~ and D, show a tendency to decrease with increasing Su due to diverse evolution processes in IWCs with different sizes. There are three main reasons leading to the formation of IWCs： varying stream power due to the meandering principal channel; development of the river corridor due to the weakening of geologic structure control; and high stability of interchannel wetlands due to conservation by shoreline vegetation.
文摘In the past decades, two large scale coastal engineering projects have been carried out in the Deep Bay surrounded by Shenzhen City and Hong Kong Special Administrative Region. One project is Shenzhen River channel regulation and the other is the sea reclamation along the seashore on the Shenzhen side. The two projects are very close to the two national nature reserves, specifically Futian in Shenzhen and Mai Po in Hong Kong, which are important wetland ecosystems worldwide. This paper aims to identify and monitor the mangrove wetland changes with time series of Landsat Thematic Mapper images pre and post to the two engineering projects being launched. Coupled analysis of the image interpretation results and tidal data acquired at the same time in the context of the two works reveals that the mangrove wetland area has increased from year 1989 to 1994, and has changed little from year 1994 to 2002. Binary coding is applied to reveal the distribution image of mangrove at each phase, and the coding image shows that the construction of the two coastal engineering projects has caused frequent changes in mangrove spatial distribution. The study also shows that the change is not significant regarding to the precision of the method and the natural evolution of mangrove wetland, and the projects do not cause apparently influences upon the two national mangrove conservation zones at least for the research time period.
