Rainwater pipe network flow calculation method and system based on GIS underlying surface analysis

Abstract

The invention relates to the technical field of urban rainwater pipe network planning, design and evaluation, in particular to a rainwater pipe network flow calculation method and system based on GISunderlying surface analysis, and the method comprises the steps: building a GIS generalization model of a rainwater pipe network system based on a database file related to an inspection well and a pipeline; preprocessing the GIS generalization model, and dividing a water catchment range for the inspection well to obtain sub-drainage areas; analyzing the underlying surface of the drainage area based on land properties of the land parcel, endowing the land parcel with different land properties with different runoff coefficients, and redividing the underlying surface of the drainage area by taking the polygon of the sub-drainage area as a boundary to obtain sub-underlying surfaces; and calculating the confluence of the pipeline based on the sub underlying surface polygon geometric area and the corresponding runoff coefficient. The diversity of the underlying surface in the drainage area is fully respected, the accuracy of rainwater pipe network catchment amount calculation is improved, and a feasible calculation method is provided for planning and designing work of the rainwater pipe network in China.

Description

technical field [0001] The invention relates to the technical field of urban rainwater pipe network planning, design and evaluation, in particular to a rainwater pipe network flow calculation method and system based on GIS underlying surface analysis. Background technique [0002] At present, the most widely used in the planning and design of my country's urban rainwater pipe network and the evaluation of the current rainwater pipe network is the reasoning formula method. Its core essence is the superposition of the constant flow equation and catchment area. The calculation method is shown in the following formula: Q=q · f · ψ. In the calculation of rainwater pipe network flow based on the reasoning formula method, Ψ usually uses the comprehensive runoff coefficient of the pipe network service area, that is, the comprehensive runoff coefficient method. At this time, the attribute information of the underlying surface of the drainage area is generalized, and various types of u...

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Problems solved by technology

[0004] At present, in the calculation method of rainwater pipeline confluence based on the mathematical model method, the hydrological characteristic parameters of the underlying surface mostly use the default values ​​of certain software (such as SWMM), although some areas have calibrated the hydrological parameters of the underlying surface through special research. However, generally speaking, this part of the data generally has insufficient pertinence and relatively few types.

In fact, my country's water supply and drainage codes and plans often only provide runoff coefficients of different underlying surfaces, and generally there is no data on the characteristics of the underlying surface matrix where the project is located for reference

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