| The city’s pipe network system,which collects sewage and transports it to sewage treatment plants,plays an important role in the recycling of water resources and is called the "blood vessel" of the city.The odor of pipes has been a long-standing problem,sewer are prone to produce various odorous compounds,which release into the atmosphere through manholes,and cause odor nuisances to nearby residents.For example,in Edmonton,Alberta,Canada,more than 10,000 complaints have been recorded over the past decade.These records contain the location and date of the complaints,but there is little information about the specific source of the odor and the severity of the odor,so no effective conclusion can be obtained.Moreover,the information of these complaints is widely distributed,which brings challenges to the analysis.In view of the above problems,this paper designs a visualization system to analyze the evolution of complaints from the perspective of time and space,and then explore the law of odor generation.First of all,this paper uses density-based clustering algorithm DBSCAN to find out the complaint intensive area and enclose it with concave hull,users can adjust the parameters to change the size of the cluster.Secondly,this paper proposes a visualization technology,using a quadtree to establish a spatial index,forming a two-dimensional to one-dimensional mapping,and then generating a grid chart according to the mapping relationship enables the user to track the temporal and spatial changes of complaints in local areas.In addition,users can use the cycle plot to check whether there is a cycle rule in the data,and users can select two areas for comparative analysis.In order to facilitate users to understand the characteristics of different communities,this paper designs a community-based complaint distribution map,and associates with the scatter matrix and bar chart,users can click on different communities to view related information.Through visual analysis,the researchers can obtain hypotheses about the odor problem of sewage pipes,further explore their cycle,outbreak and other pattern characteristics,and help the researchers identify potential problems,so as to facilitate the city managers to effectively allocate resources in appropriate places and improve the quality of life of residents. |
