From the traditional water conservancy point of view, the river management process focuses on the water level, flow rate and stormwater inlet elevation of three factors, which directly affect the success or failure of river management. River design level should be based on urban flood control planning and urban master plan to determine, at the same time, to make the rainwater inlet top higher than the design level. Urban river flow rate is an important parameter of river design, general urban river flow rate should not be too fast or too slow. River water level and flow rate can be controlled by scheduling along the locks and dams.

2, the choice of urban river cross-section

Different river sections of different river functions, there are many choices of river cross-section, such as rectangular cross-section, trapezoidal cross-section, compound cross-section and so on. Due to the tight urban land use, the spatial layout of the river is therefore subject to multiple constraints. Rectangular and trapezoidal section design can improve the land utilization rate of the waterfront, but the water level fluctuates greatly between the abundant water period and the dry water period, and the hard retaining masonry cuts off the material and energy exchanges between the river water and the riverbank, and the landscape and ecological effects are not well behaved. The section selection in the process of urban river improvement is the process of regional landscape structure selection, the number of elements constituting the landscape, type, size, shape and appearance characteristics of the ecological object of the movement of the characteristics of the direct or indirect impact, which in turn affects the overall function of the system.

River cross-section design focuses on the scope of influence of the standard flood, according to the land conditions as far as possible to reserve a wider width of the river, and then according to the basic water level of the river water level relationship design of the river channel sloughs and beach distribution ratio, which not only meets the spatial needs of urban river landscape design, but also can play a buffer role in the extreme weather conditions, to improve the flooding capacity of the urban river.

3, urban river landscape design

Urban river is a linear system, according to the characteristics of linear engineering and economic feasibility principles, choose the appropriate design scale, the core of its landscape design is based on ecological principles to guide the urban river and the surrounding ecosystems to operate benignly, maximize the use of natural forces to promote the regeneration of organic renewal capacity of the system. Above the design strategy, it is necessary to meet the landscape needs of multi-scale and multi-objective as much as possible, and to understand the differences in the needs of regional residents, office workers, and travelers at different times (e.g., different seasons, different weather, different points in time, etc.). At the same time, the designer should think about the change and development process of the natural system itself from the perspective of development, and use appropriate artificial interventions to guide the natural system to develop in a favorable direction. For example, the aquatic community and amphibious community produced in the natural state of the river will gradually evolve into a complex "aquatic, amphibious and terrestrial" ecosystem, taking into account the landscape changes brought about by the development of the system, should be made in the design phase of the scientific and reasonable solutions.

The planning and design of the river waterfront space is an important part of the current urban landscape planning, different from a single water management, waterfront space planning with ecological theory as the guiding ideology, all the issues affecting the river and riverfront ecology (such as flood control, embankment, beach, vegetation, aquatic organisms, etc.) to be taken into account to develop a comprehensive plan to restore the ecological stability of the watershed purpose.

4, urban river ecological environment and landscape benefits

River ecological restoration means the restoration of ecological functions of the river and waterfront, which can support the normal operation and derivation of the river ecosystem. Generally speaking, the ecological functions of the river corridor mainly include habitat function, channel function, filtering and barrier function, source and sink function, etc., . In the process of river management, the embankment formed by hard lining can be considered as an artificial corridor, and according to the analysis of distance one benefit of artificial corridor, its economic benefit gradually decreases with the extension of distance, while the environmental benefit of natural corridor will gradually increase with the extension of distance. Among them, there exists an equilibrium point in which the economic benefits of artificial corridors and the environmental benefits of natural corridors are roughly equal under this length condition. This reflects the fact that urban river channels can build on their strengths and avoid their weaknesses through moderate artificial intervention, and can also be interpreted to mean that moderate localized lining can improve the flood control benefits and play a positive role in the safety of regional public **** and property.

Urban river ecological restoration design, in the important parts of the river need to be reinforced by artificial measures, to protect the economic benefits and play a positive role in the comprehensive benefits of the environment. Landscape ecological design needs to understand the connectivity between landscape elements, avoid reducing landscape diversity and biodiversity, and consider retaining habitats and corridors in key locations that affect biological communities. In ecosystem design, native plants should be used as much as possible to reduce the damaging effects of invasive alien species on the ecosystem. The design of the riverbed slope drop should avoid the big drop program, and fully consider the fish migration and upstream and downstream two-way material and energy connection.