A new comprehensive ecological risk index for risk assessment on Luanhe River, China

2017 ◽  
Vol 40 (5) ◽  
pp. 1965-1978 ◽  
Author(s):  
Kun Bao ◽  
Jing-ling Liu ◽  
Xiao-guang You ◽  
Xuan Shi ◽  
Bo Meng
Complexity ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Min Guo ◽  
Shijun Wang

The agro-pastoral ecotone, an ecological transition zone connecting adjacent areas of agricultural planting area and grassland animal husbandry, has three features: a complex natural condition, relatively pronounced population pressure, and a fragile ecological environment. In this study, we conducted an ecosystem risk assessment in the western part of Jilin Province, China, based on multiscale and multitemporal remote sensing images and land-use data. Furthermore, we focused on land-use change from 1995 to 2015 by applying the dynamic change information survey method and carrying out a transfer track analysis. The results revealed three main findings. (1) The ecological risk index at the scale of 3 km × 3 km harbors significant spatial correlation. (2) The ecological risk index of unutilized land, forest land, and grassland is relatively high for each, and their anti-interference ability is weak, while the ecological risk index of construction land and water area is the lowest. (3) Human interference, e.g., construction activities and cultivated land occupation, is the leading factor driving the exacerbation of ecological risk and frequent land-use type conversions. At the study period’s end, a trend of slight contraction in the high-risk areas was found, indicating that land-use regulation and land protection policies have had significantly positive impact upon the lands’ ecological value. The overall study identified a reasonable research scale for eco-environmental risk assessment and discerned relationships between regional land-use changes through geospatial analysis. Moreover, our findings can help provide practical case study information applicable to similar regions with agro-pastoral ecotones.


2018 ◽  
Vol 56 (2C) ◽  
pp. 72-79
Author(s):  
Dang Van Hieu

Tam Giang - Cau Hai lagoon plays an important role in coastal ecosystems of Thua Thien Hue Province. The present study aims to determine three toxic elements (Pb, As, Hg) in the surface sediment and to assess the ecological risk of the selected metal in this area. Sediment samples and water quality were collected at 9 stations in rainy and dry seasons. Toxic metals were determined following the USEPA methods 3050A for measuring by atomic absorption spectrophotometer. Concentrations of Hg, Pb and As in the study area were in the range of 0-2.64 mg/kg, 4.83-22.13 mg/kg and 1.18-6.24 mg/kg, respectively. The results showed that concentration of Hg in sediment of most sampling sites were exceeded the National Technical Regulation on Sediment Quality (QCVN 43:2012/BTNMT), while Pb and As were below the regulated level. Ecological risk assessment presented that investigated metals posed medium to high risk to ecology. The estimated ecological risk index (ERI) ranged from 43.9 to 582.9 with the order of Hg>As>Pb. The highest ecological risk was found at the stations closed to the Thuan An inlet and ship construction area.


2014 ◽  
Vol 1051 ◽  
pp. 552-556
Author(s):  
Xiao Tian Ma ◽  
Ren Jun Liang ◽  
Ji Cai Qiu ◽  
Li Zhi Wang ◽  
Xiu Zhen Wang

This study used four acid digestion methods and the Tessier five-step method to analyze the content characteristics of the elements Hg and As in samples. Further measures included the enrichment factor, geoaccumulation index and potential ecological risk index, for a comprehensive ecological risk assessment of pollution by Hg and As. The average contents were 1.16 mg·kg-1 for Hg and 46.76 mg·kg-1 for As.The two class natural background level was compared to evaluate the cumulative pollution index: among all sampling points, the Hg Igeo mean was-0.55, indicating this element was non-polluting, and the As Igeo mean of 0.23 indicated pollution-free to light pollution. The overall potential ecological risk index (RI) had a mean of 64.93, which indicated slight potential ecological harm to the wetland system.


Forests ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 891
Author(s):  
Qian Zhang ◽  
Guilin Han ◽  
Xingliang Xu

Human agricultural activities have resulted in widespread land degradation and soil contamination in the karst areas. However, the effects of reforestation after agricultural abandonment on the mobility risks and contamination of heavy metals have been rarely reported. In the present study, six soil profiles were selected from cropland and abandoned cropland with reforestation in the Puding karst regions of Southwest China. The Community Bureau of Reference (BCR) sequential extraction method was used to evaluate the compositions of different chemical fractions of soil heavy metals, including Fe, Mn, Cr, Zn, Ni, and Cd. The total contents of Cr, Ni, Zn, Cd, and Mn in the croplands were significantly higher than those in the abandoned croplands. For all soils, Cr, Ni, Zn, and Fe were mainly concentrated in the residual fractions (>85%), whereas Mn and Cd were mostly observed in the non-residual fractions (>65%). The non-residual fractions of Cd, Cr, Ni, and Zn in the croplands were higher than those in the abandoned croplands. These results indicated that the content and mobility of soil heavy metals decreased after reforestation. The individual contamination factor (ICF) and risk assessment code (RAC) showed that Cd contributed to considerable contamination of karst soils. The global contamination factor (GCF) and potential ecological risk index (RI) suggested low contamination and ecological risk of the investigated heavy metals in the croplands, moreover they can be further reduced after reforestation.


2017 ◽  
Vol 43 (1) ◽  
pp. 34-47 ◽  
Author(s):  
Cem Tokatli

Abstract Gala Lake National Park that has an international importance is one of the most important wetland ecosystems for Turkey. As same as many aquatic habitats, Gala Lake is under a significant anthropogenic pressure originated from agricultural activities conducted around the lake and from industrial discharges by means of Ergene River. The aim of this study was to evaluate the sediment quality of Gala Lake and Irrigation Canal by investigating some toxic element accumulations (As, B, Ni, Cr, Pb, Cd, Zn and Cu) from a statistical perspective. Pearson Correlation Index (PCI) and Factor Analysis (FA) were applied to detected data in order to determine the associated contaminants and effective factors on the system. Potential Ecological Risk Index (RI) and Biological Risk Index based sediment quality guidelines (mERM-Q) applied to detected data in order to assess the ecological and biological risks of heavy metals in the ecosystem. Also Geographic Information System (GIS) technology was used to make visual explanations by presenting distribution maps of investigated elements. According to the results of PCI, significant positive correlations were recorded among the investigated toxic elements at 0.01 significance level. According to the results of FA, two factors, which were named as “Agricultural Factor” and “Industrial Factor”, explained 86.6% of the total variance. According to the results of Potential Ecological Risk Index, cadmium was found to be the highest risk factor and according to results of Biological Risk Index, nickel and chromium were found to be the highest risk factors for Gala Lake and Irrigation Canal. As a result of the present study, it was also determined that heavy metal contents in sediments of Gala Lake National Park reached to critical levels and the system is intensively under effect of agricultural and industrial originated pollution.


2017 ◽  
Vol 8 (30) ◽  
pp. 37-45
Author(s):  
Mehri Rezaei ◽  
Ali Mehdinia ◽  
Abolfazl Saleh ◽  
Soroush Modabberi

2014 ◽  
Vol 955-959 ◽  
pp. 2280-2284
Author(s):  
Kai Yue Gong ◽  
Pei Shi Qi ◽  
Yun Zhi Liu

In this study, the distribution and enrichment characters of heavy metals were explored. And the potential ecological risk levels of heavy metals were evaluated by geo-accumulation index method and potential ecological risk index method. The concentrations of heavy metals in sediments of Harbin section of Songhua River are: Zn>Pb>Cr>Cu>Ni>Cd. The enrichment degree of Zn is the highest, while Cd is the lowest. The potential ecological risk indexes of heavy metals in the sediments of section of Songhua River in Harbin are: Cd>Pb>Cu>Zn>Ni>Cr. The main heavy metals pollution is Cd, which has low content but considerable potential ecological risk and contributes most to RI. The ecological risk level of heavy metals in the sediments of the section of Songhua River in Harbin is moderate.


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