Identification Sources and High-Risk Areas of Sediment Heavy Metals in the Yellow River by Geographical Detector Method

Jianxiu Hao,Hongbing Fang,Jun Ren,Ling Tao

doi:10.3390/w13081103

Jianxiu Hao, Hongbing Fang + Show 2 more

Open Access

https://doi.org/10.3390/w13081103

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Journal: Water	Publication Date: Apr 16, 2021
Citations: 8	License type: CC BY 4.0

Affiliation: Lanzhou Jiaotong University

Abstract

In order to determine the key influencing factors, risk areas, and source pathways of heavy metals in the sediment of the Yellow River, 37 samples were collected in the surface sediment (0–5 cm) of the Inner Mongolia section of the Yellow River main stream for the determination of heavy metals copper (Cu), nickel (Ni), zinc (Zn), chromium (Cr), lead (Pb), and cadmium (Cd). Based on the geographical detector model (GDM) and ArcGIS 10.2 software, this paper selected 6 heavy metals and 15 influencing factors, including 8 natural factors and 7 anthropogenic factors, to detect key influencing factors, risk areas, and sources of heavy metals. The results showed that: (1) The average contents of heavy metals Cr and Cd in the sediments exceeded the average value in soil, the world average concentration in the shales, and the first-level standard of soil environmental quality in China, and they were the main risk metals; (2) Vegetation coverage (VC) was the largest influencing factor for the spatial distribution of heavy metals in the sediment, followed by per capita income (PI), and land use type (LUT) and road network density (RD) were smaller influencing factors. The interactions of the factors were enhanced; (3) The Wuhai section for a risk area was mainly polluted by Cd and Pb, which were caused by atmospheric deposition and industrial emission. The Baotou section for a risk area was mainly polluted by Cr, which mainly originated from river transportation and industrial discharge. The conclusions can provide a scientific basis for the environmental protection and management of the different areas in the Inner Mongolia section of the Yellow River.

Highlights

Heavy metals are toxic [1] and can accumulate within the bodies of humans, endangering health [2]
Sediments are sources and sinks of river heavy metals. When environmental conditions such as pH, electrical conductivity (EC), chemical oxygen demand (COD), and organic matter change, heavy metals fixed in sediments can be released from sediments again and cause secondary river pollution [4]; sediments act as indicators of heavy metal pollution in rivers [5]
The study area focuses on the Inner Mongolia section located in the upper stream Yellow River, which flows through Wuhai City (Hainan, Wuda, and Haibowan District), Alxa League (Alxa Left Banner), Byan Nur City (Dengkou, Hangjin Youqi, Linhe, Wuyuan, and Wulate Qianqi), Baotou City (Jiuyuan, Donghe, and Tumote Youqi), and Hohhot City (Togtoh) for 627 km [31] (Figure 1)

Summary

Introduction

Heavy metals are toxic [1] and can accumulate within the bodies of humans, endangering health [2]. Heavy metals Cu, Ni, Zn, Cr, Pb, and Cd have been listed as environmental pollutants of priority control in China [3]. Sediments are sources and sinks of river heavy metals. When environmental conditions such as pH, electrical conductivity (EC), chemical oxygen demand (COD), and organic matter change, heavy metals fixed in sediments can be released from sediments again and cause secondary river pollution [4]; sediments act as indicators of heavy metal pollution in rivers [5]. Heavy metals in river sediments have been a research hotspot domestically in China and internationally [6]

Methods

Results

Discussion

Conclusion