The report describes the design and structure of TURBAN Web GIS. We are developing a web-based GIS application for urban environmental assessment for project pilot cities. The app demonstrates the tool for planners and the public and creates a spatial representation of different aspects of the urban environment. Modern cities are growing and rapidly changing systems that require periodic assessment of the geo-ecological state. An objective evaluation of various parts of the urban environment is a necessary guarantee of sustainable and stable development of territories. However, it is only possible considering many factors represented by numerous parameters. The growing complexity of the urban environment leads not only to the need for accurate spatial information in real-time but also creates new challenges to obtaining information valuable for urban citizens. Web GIS technologies make it possible to combine all heterogeneous information about the ecological state of a city into a single data system that is available for use. A web GIS makes it possible to assess the state of the urban environment and present information in spatially visual forms. As online maps simultaneously become more research tools, citizen science activities are starting to implement web GIS applications to support research areas such as ecology and urban studies. The Web GIS is built on the cloud-based ArcGIS (online) software to create and share interactive web maps. We integrate project knowledge through thematic maps into a web GIS framework that links urban landscapes and various urban features with quantitative data from model scenarios. The design of our web GIS combining open data and science data and can quickly present the results and participate in the process of city management. Web-based interactive urban maps serve as a visual tool for urban air quality and the spatial and temporal characteristics of different aspects of the urban environment. The application was developed for Bergen, Norway, with a potential extension of the Praha case study. The Web GIS consists of two elements: WebStory maps of urban climate and pollution and interactive WebGIS presenting a thematic layer of the urban environment. Web GIS is changing how maps and spatial data are shared and accessed.