Urban non-point source pollution risk recognition method and device based on GIS platform

Abstract

The invention discloses an urban non-point source pollution risk recognition method and device based on a GIS platform. The method comprises the steps: carrying out the calculation of the rasterized DEM data in a target urban region, and obtaining the raster data of the flow direction, the accumulated catchment area and the gradient, so as to determine the topographic index raster data; correcting the topographic index raster data by using raster data of impervious rate, underground water depth and soil saturation permeability coefficient to obtain hydrological sensitive index raster data; calculating a non-point source pollutant source strength index of each type of land utilization according to the pollutant characteristic data and the rainfall intensity data of different types of land utilization; rasterizing the non-point source pollutant source strength index to obtain non-point source pollutant source strength index raster data; and after the hydrological sensitivity index raster data and the non-point source pollutant source strength index raster data are standardized, calculating urban non-point source pollution risk index raster data. According to the method, the influence of urban characteristic factors and rainfall intensity factors is considered, and the urban non-point source pollution risk can be evaluated more accurately.

Description

technical field [0001] The present invention relates to the technical field of area source pollution risk assessment, in particular to a method and device for identifying urban area source pollution risks based on a geographic information system (Geographic Information System, GIS) platform. Background technique [0002] In the past 20 years, my country has experienced a rapid urbanization process, and the urban construction land area has increased by nearly 154%. With the continuous expansion of urban construction areas, the risk of water environmental pollution caused by urban non-point source pollutants driven by rainfall runoff has attracted more and more attention from researchers. Controlling pollutants from the source is an important means to alleviate the problem of urban non-point source pollution. Therefore, it is of great significance to accurately identify the high-risk areas of urban non-point source pollution output for the efficient realization of urban non-po...

AI Technical Summary

Problems solved by technology

[0008] (1) The impact of differences in urban land use types on the generation characteristics of non-point source pollutants is not considered

[0009] There are large differences in the accumulation of non-point source pollutants in urban areas such as residential, industrial, commercial, and transportation land. However, existing methods either evaluate at the sub-basin scale when identifying non-point source pollution risks, or use a unified method for urban land use. None of these can reflect the differences in the accumulation characteristics of different types of surface source pollution loads in urban areas, and cannot be directly used for non-point source pollution risk identification in highly urbanized areas

[0010] (2) The influence of impermeability on surface flow generation and confluence characteristics is not considered

Existing methods often only consider the differences in the migration of pollutants due to the impact of surface runoff potential when quantifying the migration risk of non-point source pollutants, but ignore the impact of pollutants on the start of flushing due to rainfall characteristics, etc. The differences in the migration trends exhibited by the influence of

When the rainfall intensity is small, some pollutants do not migrate or can only migrate for a very short distance due to the limitation of runoff scour power. In this case, the application of existing methods often leads to overestimation of the migration risk of non-point source pollutants

[0014] (4) Did not form a practical tool

[0015] Most of the existing research only stays at the method design stage, and there is no practical tool to further form a system based on the method system, making most methods fail to provide practical help for the actual non-point source pollution control

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