CN-122023056-A - Regional soil heavy metal water input type pollution risk assessment method and system

CN122023056ACN 122023056 ACN122023056 ACN 122023056ACN-122023056-A

Abstract

The invention provides a regional soil heavy metal water input type pollution risk assessment method and system, and relates to the technical field of soil pollution risk assessment. Aiming at the problem of insufficient precision of the existing pollution risk assessment, the method comprises the steps of obtaining sub-basin boundaries, cadmium-containing wastewater discharge points, farmland distribution data, grain yield, farmland irrigation water consumption and flood inundation farmland area, calculating a cadmium discharge hazard index, an irrigation exposure index, a flood exposure index and a vulnerability index according to the obtained data, calculating cadmium pollution risk values of each sub-basin irrigation path and each flood path after standardized treatment of key indexes, dividing the irrigation exposure type and the flood exposure type according to set thresholds, determining the comprehensive risk type by combining double-path risk values, adopting a sensitivity analysis model, taking the key indexes as input quantity and the double-path risk values as output quantity, and identifying the maximum sensitive factor influenced by the risk values through a set sampling and statistical method. The method realizes comprehensive and accurate assessment of the risk of river basin scale pollution.

Inventors

SHEN ZHICHENG
SHI HUADING
XU JINGWEN

Assignees

生态环境部土壤与农业农村生态环境监管技术中心

Dates

Publication Date: 20260512
Application Date: 20260213

Claims (10)

1. The regional soil heavy metal water input type pollution risk assessment method is characterized by comprising the following steps of: S1, acquiring basic data in a target area, wherein the basic data comprise a plurality of sub-drainage basin boundaries, cadmium-containing wastewater discharge points, farmland distribution data, grain yield, farmland irrigation water consumption and flood inundation farmland areas; S2, calculating key indexes based on the acquired basic data, wherein the key indexes comprise a cadmium emission hazard index, an irrigation exposure index, a flood exposure index and a vulnerability index; S3, carrying out standardized treatment on the key indexes, and calculating irrigation path cadmium pollution risk values and flood path cadmium pollution risk values of all sub-watercourses according to the standardized key indexes; S4, dividing the cadmium emission hazard index, the irrigation exposure index and the flood exposure index of each sub-basin into a plurality of grades according to a set threshold value to obtain an irrigation exposure type and a flood exposure type; S5, according to the irrigation exposure type and the flood exposure type, combining the cadmium pollution risk value of each sub-basin irrigation path and the cadmium pollution risk value of the flood path to obtain the comprehensive risk type of each sub-basin; S6, a set sensitive analysis model is adopted, four key indexes are used as input variables, irrigation path cadmium pollution risk values and flood path cadmium pollution risk values are used as output variables, and a set sampling and statistical method is adopted to find out the sensitive input variables with the greatest influence on the risk values.
2. The regional soil heavy metal water input type pollution risk assessment method according to claim 1, wherein in S2, calculating a key index based on the obtained basic data comprises: determining a cadmium emission hazard index by calculating the ratio of the number of cadmium-containing wastewater emission points in a sub-basin to the cultivated land area of the sub-basin; Determining an irrigation exposure index by calculating the ratio of the irrigation water consumption of the cultivated land in the sub-river basin to the cultivated land area of the sub-river basin; Determining a flood exposure index by calculating the ratio of the flood submerged cultivated area in a sub-river basin to the total cultivated area of the sub-river basin; and determining the vulnerability index by calculating the ratio of the grain yield in the sub-river basin to the cultivated land area of the sub-river basin.
3. The regional soil heavy metal water input type pollution risk assessment method according to claim 1, wherein in S3, the normalizing the key index comprises: and carrying out normalization treatment on the cadmium emission hazard index, the irrigation exposure index, the flood exposure index and the vulnerability index so as to unify the value ranges of the key indexes.
4. The regional soil heavy metal water input type pollution risk assessment method according to claim 3, wherein calculating the irrigation pathway cadmium pollution risk value of each sub-basin according to the standardized key index comprises: Multiplying the normalized cadmium emission hazard index, the normalized irrigation exposure index and the normalized vulnerability index to obtain an irrigation path cadmium pollution risk value.
5. The regional soil heavy metal water input type pollution risk assessment method according to claim 3, wherein calculating the flood path cadmium pollution risk value of each sub-basin according to the standardized key index comprises: multiplying the normalized cadmium emission hazard index, the normalized flood exposure index and the normalized vulnerability index to obtain a flood path cadmium pollution risk value.
6. The regional soil heavy metal water input type pollution risk assessment method according to claim 1, wherein in S4, the cadmium emission hazard index, the irrigation exposure index and the flood exposure index of each sub-basin are classified into a plurality of levels according to a set threshold value to obtain an irrigation exposure type and a flood exposure type, comprising: Setting two thresholds, namely a first threshold and a second threshold, by adopting a three-quantile method; When the index value in the cadmium emission hazard index, the irrigation exposure index and the flood exposure index is smaller than or equal to a first threshold value, the grade of the index corresponding to the index value is low; When the index value in the cadmium emission hazard index, the irrigation exposure index and the flood exposure index is larger than the first threshold value and smaller than or equal to the second threshold value, the grade of the index corresponding to the index value is medium grade; When the index value in the cadmium emission hazard index, the irrigation exposure index and the flood exposure index is larger than the second threshold value, the grade of the index corresponding to the index value is high; The method comprises the steps of combining the grade of the cadmium emission hazard index with the grade of the irrigation exposure index, determining the type of irrigation exposure, combining the grade of the cadmium emission hazard index with the grade of the flood exposure index, and determining the type of flood exposure.
7. The regional soil heavy metal water input type pollution risk assessment method according to claim 1, wherein the comprehensive risk type of each sub-basin is obtained by combining the irrigation path cadmium pollution risk value and the flood path cadmium pollution risk value of each sub-basin according to the irrigation exposure type and the flood exposure type, and comprises the following steps: Setting a comprehensive risk threshold by adopting a three-quantile method, wherein the comprehensive risk threshold is a third threshold and a fourth threshold respectively; calculating the comprehensive risk of each sub-basin based on the irrigation exposure type, the flood exposure type, the irrigation path cadmium pollution risk value and the flood path cadmium pollution risk value; The comprehensive risk type is a low risk type when the comprehensive risk is smaller than or equal to a third threshold value, a medium risk type when the comprehensive risk is larger than the third threshold value and smaller than or equal to a fourth threshold value, and a high risk type when the comprehensive risk is larger than the fourth threshold value.
8. The regional soil heavy metal water input type pollution risk assessment method according to claim 7, wherein the comprehensive risk is calculated by the following steps: And calculating the arithmetic sum of the cadmium pollution risk value of the irrigation path and the cadmium pollution risk value of the flood path to obtain the comprehensive risk.
9. The regional soil heavy metal water input type pollution risk assessment method according to claim 1, wherein the set sampling method comprises a self-help sampling method, and the statistical method comprises a cumulative distribution function difference analysis method of a cole Mo Geluo f-smirnov statistic.
10. A regional soil heavy metal water input type pollution risk assessment system for performing the regional soil heavy metal water input type pollution risk assessment method of any one of claims 1 to 9, the system comprising: the system comprises a data acquisition module, a data storage module and a data storage module, wherein the data acquisition module is used for acquiring basic data in a target area, and the basic data comprise a plurality of sub-drainage basin boundaries, cadmium-containing wastewater discharge points, farmland distribution data, grain yield, farmland irrigation water consumption and flood inundation farmland areas; An index calculation module for calculating key indexes based on the obtained basic data, wherein the key indexes comprise a cadmium emission hazard index, an irrigation exposure index, a flood exposure index and a vulnerability index; The risk value calculation module is used for carrying out standardized treatment on the key indexes, and calculating irrigation path cadmium pollution risk values and flood path cadmium pollution risk values of all sub-watercourses according to the standardized key indexes; The exposure type determining module is used for dividing the cadmium emission hazard index, the irrigation exposure index and the flood exposure index of each sub-basin into a plurality of grades according to a set threshold value so as to obtain irrigation and flood exposure types; the comprehensive risk calculation module is used for combining the cadmium pollution risk value of each sub-basin irrigation path and the cadmium pollution risk value of the flood path according to the irrigation and flood exposure types to obtain the comprehensive risk type of each sub-basin; The analysis module is used for adopting a set sensitive analysis model, taking four key indexes as input variables, taking irrigation path cadmium pollution risk values and flood path cadmium pollution risk values as output variables, and finding out the sensitive input variables with the greatest influence on the risk values through a set sampling and statistical method.

Description

Regional soil heavy metal water input type pollution risk assessment method and system Technical Field The invention relates to the technical field of soil pollution risk assessment, in particular to a regional soil heavy metal water input type pollution risk assessment method and system. Background Soil heavy metal pollution has become a significant environmental concern worldwide, with water-infused pollution being an important route for regional soil heavy metal accumulation. The watershed is used as a basic unit of hydrologic cycle and substance migration, and the internal hydrologic hydraulic conditions directly influence the regional transmission and distribution of heavy metal pollutants, so that the development of the watershed-scale soil heavy metal water input type pollution risk assessment is of great significance. In the prior art, soil heavy metal pollution risk assessment focuses on a single pollution path, or only carries out case analysis aiming at a specific area, and comprehensive consideration of irrigation and flood paths is lacking. Meanwhile, the traditional evaluation method often ignores sensitivity analysis of risk factors, and is difficult to identify key influence factors, so that the accuracy of an evaluation result is insufficient, and a targeted support can not be provided for regional pollution prevention and control. Therefore, developing a regional soil heavy metal water input type pollution risk assessment method and system is important for improving the precision of pollution risk assessment. Disclosure of Invention Aiming at the problem of insufficient accuracy of heavy metal water input type pollution risk assessment of the existing regional soil, the invention provides a regional soil heavy metal water input type pollution risk assessment method, which specifically comprises the following steps: S1, acquiring basic data in a target area, wherein the basic data comprise a plurality of sub-drainage basin boundaries, cadmium-containing wastewater discharge points, farmland distribution data, grain yield, farmland irrigation water consumption and flood inundation farmland areas; S2, calculating key indexes based on the acquired basic data, wherein the key indexes comprise a cadmium emission hazard index, an irrigation exposure index, a flood exposure index and a vulnerability index; S3, carrying out standardized treatment on the key indexes, and calculating irrigation path cadmium pollution risk values and flood path cadmium pollution risk values of all sub-watercourses according to the standardized key indexes; S4, dividing the cadmium emission hazard index, the irrigation exposure index and the flood exposure index of each sub-basin into a plurality of grades according to a set threshold value to obtain an irrigation exposure type and a flood exposure type; S5, according to the irrigation exposure type and the flood exposure type, combining the cadmium pollution risk value of each sub-basin irrigation path and the cadmium pollution risk value of the flood path to obtain the comprehensive risk type of each sub-basin; S6, a set sensitive analysis model is adopted, four key indexes are used as input variables, irrigation path cadmium pollution risk values and flood path cadmium pollution risk values are used as output variables, and a set sampling and statistical method is adopted to find out the sensitive input variables with the greatest influence on the risk values. Further, in the step S2, key indexes are calculated based on the obtained basic data, wherein the key indexes comprise a cadmium emission hazard index is determined by calculating the ratio of the number of cadmium-containing wastewater discharge points in a sub-river basin to the cultivated land area of the sub-river basin, an irrigation exposure index is determined by calculating the ratio of the cultivated land irrigation water consumption in the sub-river basin to the cultivated land area of the sub-river basin, a flood exposure index is determined by calculating the ratio of the flood submerged cultivated land area in the sub-river basin to the total cultivated land area of the sub-river basin, and a vulnerability index is determined by calculating the ratio of grain yield in the sub-river basin to the cultivated land area of the sub-river basin. Further, in the step S3, the normalization processing of the key indexes comprises the normalization processing of the cadmium emission hazard index, the irrigation exposure index, the flood exposure index and the vulnerability index so as to unify the value ranges of the key indexes. Further, calculating the irrigation path cadmium pollution risk value of each sub-basin according to the standardized key indexes comprises multiplying the standardized cadmium emission hazard index, the standardized irrigation exposure index and the standardized vulnerability index to obtain the irrigation path cadmium pollution risk value. Further, calculating the flood path cadmi