Ascertaining the relationship between "source-sink" landscape and non-point source(NPS) pollution is crucial for reducing NPS pollution, however, it is not easy to realize this target on cell unit scale. To ...Ascertaining the relationship between "source-sink" landscape and non-point source(NPS) pollution is crucial for reducing NPS pollution, however, it is not easy to realize this target on cell unit scale. To reveal the relationships between "sourcesink" landscape and NPS pollution based on cell units of a small catchment in the Three Gorges Reservoir Region(TGRR), the runoff and nutrient yields were simulated first by rainfall events on a cell unit scale based on the Annualized AGricultural Non-Point Source Pollution Model(AnnAGNPS). Landscape structure and pattern were quantified with "sourcesink" landscape indicators based on cell units including landscape area indices and locationweighted landscape indices. The results showed that:the study case of small Wangjiagou catchment highlighted a good prediction capability of runoff and nutrient export by the AnnAGNPS model. Throughout the catchment, the spatial distribution trends of four location-weighted landscape indices were similar to the trends of simulated total nitrogen(TN) and total phosphorus(TP), which highlighted the importance of spatial arrangement of "source" and "sink" landscape types in a catchment when estimating pollutant loads. Results by Pearson correlation analysis indicated that the location-weighted landscape index provided a more comprehensive account of multiple factors, and can better reflect NPS-related nutrient loss than other landscape indices applied in single-factor analysis. This study provides new findings for applying the "source-sink" landscape indices based on cell units in small catchments to explain the effect of "source-sink" landscape on nutrient export based on cell unit, and helps improve the understanding of the correlation between "source-sink" landscape and NPS pollution.展开更多
Taihu Lake is located at the center of Changjiang delta region, the Lake and its effluent rivers are important water sources for 40 million around inhabitants and rapidly increasing industrial factories in Shanghai, J...Taihu Lake is located at the center of Changjiang delta region, the Lake and its effluent rivers are important water sources for 40 million around inhabitants and rapidly increasing industrial factories in Shanghai, Ji-angsu and Zhejiang. The pollutants originate mainly from acidy rain, home sewage of the vast number of inhabitants, livestock manure, agricultural fertilizers & pesticides applied over fields in the drainage basin, and the industrial sewage. Due to the kinds of pollutants, the Lake water is getting highly eutrophic, with frequent blooms of blue-green algae. Compared with point-source pollutants, diffuse pollution is much com-plicated and difficult to control. Thus combating non-point pollution (NPP) is paid much great attention. Based on analysis on source-sink of NPP in Taihu Lake basin, it is concluded that the function of forests on NPP control is multiple and important by both source reduction and sink expansion. The primary objective of planting trees through constructing forested wetlands and establishing riparian forest buffers is to control soil & water erosion, decrease agrochemicals application, and improve farming conditions in the region of Taihu Lake basin. Moreover forests help to intercept acidy rain, protect streambanks, uptake nutrients, hold up pollutants and provide habitat for wildlife.展开更多
针对Sink节点移动所带来的时延问题,提出了一种基于最优路径的移动Sink数据收集方案OPDG(Data Gathering Based on Optimal-Path)。首先由MWHA(Minimum Weighted Heuristic Algorithm)算法得到汇聚节点RP(Rendezvous Point)的集合,然后...针对Sink节点移动所带来的时延问题,提出了一种基于最优路径的移动Sink数据收集方案OPDG(Data Gathering Based on Optimal-Path)。首先由MWHA(Minimum Weighted Heuristic Algorithm)算法得到汇聚节点RP(Rendezvous Point)的集合,然后根据这些RP节点求出移动Sink的最佳驻留点集合,最后求出经过驻留点的最短路径。Sink沿着这条路径周期性采集数据。通过NS-2中大量的仿真实验结果表明,与已有算法相比,OPDG算法能最大限度的减小时延,延长网络的生命周期。展开更多
数据收集是部署无线传感网络WSNs(Wireless Sensor Networks)基本目的。而采用移动Sink方式收集节点数据是解决数据收集效率的有效措施。为此,提出基于遗传算法的移动Sink数据采集算法GMSDC(Genetic algorithm-based Mobile Sink Data C...数据收集是部署无线传感网络WSNs(Wireless Sensor Networks)基本目的。而采用移动Sink方式收集节点数据是解决数据收集效率的有效措施。为此,提出基于遗传算法的移动Sink数据采集算法GMSDC(Genetic algorithm-based Mobile Sink Data Collecting)。GMSDC算法利用遗传算法求解最佳驻留点,再由这些驻留点构建Sink移动路径。仿真结果表明,相比于EDAMS算法,GMSDC算法增加了数据收集量。展开更多
Energy conservation is becoming the main critical issue in wireless sensor network and also the main research area for most of the researchers. For improving the energy efficiency, sink mobility is used with constrain...Energy conservation is becoming the main critical issue in wireless sensor network and also the main research area for most of the researchers. For improving the energy efficiency, sink mobility is used with constrain path in wireless sensor network. In order to solve these optimization problems, inter cluster Ant Colony Optimization Algorithm (ACO) is used with mobile sink (MS) and rendezvous nodes (RN). The proposed algorithm will improve 30% more network lifetime than the existing algorithm and prompts high accurate delivery of packets in highly dense network.展开更多
基金supported by the National Natural Science Foundation of China (Nos. 41671291)
文摘Ascertaining the relationship between "source-sink" landscape and non-point source(NPS) pollution is crucial for reducing NPS pollution, however, it is not easy to realize this target on cell unit scale. To reveal the relationships between "sourcesink" landscape and NPS pollution based on cell units of a small catchment in the Three Gorges Reservoir Region(TGRR), the runoff and nutrient yields were simulated first by rainfall events on a cell unit scale based on the Annualized AGricultural Non-Point Source Pollution Model(AnnAGNPS). Landscape structure and pattern were quantified with "sourcesink" landscape indicators based on cell units including landscape area indices and locationweighted landscape indices. The results showed that:the study case of small Wangjiagou catchment highlighted a good prediction capability of runoff and nutrient export by the AnnAGNPS model. Throughout the catchment, the spatial distribution trends of four location-weighted landscape indices were similar to the trends of simulated total nitrogen(TN) and total phosphorus(TP), which highlighted the importance of spatial arrangement of "source" and "sink" landscape types in a catchment when estimating pollutant loads. Results by Pearson correlation analysis indicated that the location-weighted landscape index provided a more comprehensive account of multiple factors, and can better reflect NPS-related nutrient loss than other landscape indices applied in single-factor analysis. This study provides new findings for applying the "source-sink" landscape indices based on cell units in small catchments to explain the effect of "source-sink" landscape on nutrient export based on cell unit, and helps improve the understanding of the correlation between "source-sink" landscape and NPS pollution.
文摘Taihu Lake is located at the center of Changjiang delta region, the Lake and its effluent rivers are important water sources for 40 million around inhabitants and rapidly increasing industrial factories in Shanghai, Ji-angsu and Zhejiang. The pollutants originate mainly from acidy rain, home sewage of the vast number of inhabitants, livestock manure, agricultural fertilizers & pesticides applied over fields in the drainage basin, and the industrial sewage. Due to the kinds of pollutants, the Lake water is getting highly eutrophic, with frequent blooms of blue-green algae. Compared with point-source pollutants, diffuse pollution is much com-plicated and difficult to control. Thus combating non-point pollution (NPP) is paid much great attention. Based on analysis on source-sink of NPP in Taihu Lake basin, it is concluded that the function of forests on NPP control is multiple and important by both source reduction and sink expansion. The primary objective of planting trees through constructing forested wetlands and establishing riparian forest buffers is to control soil & water erosion, decrease agrochemicals application, and improve farming conditions in the region of Taihu Lake basin. Moreover forests help to intercept acidy rain, protect streambanks, uptake nutrients, hold up pollutants and provide habitat for wildlife.
文摘针对Sink节点移动所带来的时延问题,提出了一种基于最优路径的移动Sink数据收集方案OPDG(Data Gathering Based on Optimal-Path)。首先由MWHA(Minimum Weighted Heuristic Algorithm)算法得到汇聚节点RP(Rendezvous Point)的集合,然后根据这些RP节点求出移动Sink的最佳驻留点集合,最后求出经过驻留点的最短路径。Sink沿着这条路径周期性采集数据。通过NS-2中大量的仿真实验结果表明,与已有算法相比,OPDG算法能最大限度的减小时延,延长网络的生命周期。
文摘数据收集是部署无线传感网络WSNs(Wireless Sensor Networks)基本目的。而采用移动Sink方式收集节点数据是解决数据收集效率的有效措施。为此,提出基于遗传算法的移动Sink数据采集算法GMSDC(Genetic algorithm-based Mobile Sink Data Collecting)。GMSDC算法利用遗传算法求解最佳驻留点,再由这些驻留点构建Sink移动路径。仿真结果表明,相比于EDAMS算法,GMSDC算法增加了数据收集量。
文摘Energy conservation is becoming the main critical issue in wireless sensor network and also the main research area for most of the researchers. For improving the energy efficiency, sink mobility is used with constrain path in wireless sensor network. In order to solve these optimization problems, inter cluster Ant Colony Optimization Algorithm (ACO) is used with mobile sink (MS) and rendezvous nodes (RN). The proposed algorithm will improve 30% more network lifetime than the existing algorithm and prompts high accurate delivery of packets in highly dense network.
