Study On Hydroinformatics In Urban Stormwater System And Its Application

China is experiencing a rapid process of urbanization, which results in increasingly severe water environment problems, such as water resource shortage, water environment depravation, flood disaster and so on. The urban water environment is a complicated system. According to the different urban function orientation, the different effective research methods need to be adopted based on an overall consideration of the factors. With the wide application of modern technologies, both the quantity and the quality of the available data increase rapidly. Benefit from the high quality and huge number of data, the urnderstanding of the water environment is increasing and this provides a good opportunity for the development of the mathematical models. Hydroinformatics, which combines the modern information technologies, traditional numerical simulation, experiment and monitoring methods has being becoming a effective method for the study of urban water environment.Take a small town in the arid region in north China for instance, this thesis applied hydroinformatics and the related technologies to develop the Urban Stormwater Spatial Information System (USSIS) and established the frame and functions of the USSIS based on the Geographic Information System (GIS). The USSIS is a multivariate data fusion system, with the integration of database and models.Based on the Geodatabase, the USSIS takes the advantage of object oriented technology and build a logical model of urban stormwater and the relative elements with unified modeling language (UML). The multivariate data fusion was realized using the advanced spatial data models, and the knowledge foundation of the urban stormwater system was established. This paper presents an application of DEM, in which the methods used in natural river basin system were applied to urban road and wastewater pipelines. This method was used to determe"drainage route", to divide urban runoff catchments, to extract city surface hydrological features parameters and to provide support for calculation and analysis of urban stormwater system.Soft computation is an important part of the information science system. This thesis uses differential evolution(DE)algorithm to determine the initial connection weights for artificial neural networks(ANN)to improve the computing result. Based on prediction of urban ground water level and water quality, the network structure and factors affecting the performance of the DE-BP method are analyzed, especially the effect of the correlation between training samples and prediction samples on the prediction result. The analysis shows that there is not a positive correlation between sample correlation and prediction accuracy, while the network structure and sample representativeness are significant important.Based on the GIS, the SWMM method and database technology is used together in urban runoff simulation, and the flooding area is determined by non-source flooding method.The urban stormwater spatial information system(USSIS) developed in this thesis can be used as an effective tool for urban planning, rainwater harvesting, flood mitigation, and it is also an important part of decision support system and digital urban system.