scholarly journals Exploring Variability in Landscape Ecological Risk and Quantifying Its Driving Factors in the Amu Darya Delta

2019 ◽  
Vol 17 (1) ◽  
pp. 79
Author(s):  
Tao Yu ◽  
Anming Bao ◽  
Wenqiang Xu ◽  
Hao Guo ◽  
Liangliang Jiang ◽  
...  
Keyword(s):  
High Risk ◽  
Crop Yield ◽  
Ecological Risk ◽  
Risk Index ◽  
Driving Factors ◽  
Road Density ◽  
Amu Darya ◽  
Risk Areas ◽  
Landscape Ecological ◽  
Gwr Model

Examining the drivers of landscape ecological risk can provide scientific information for planning and landscape optimization. The landscapes of the Amu Darya Delta (ADD) have recently undergone great changes, leading to increases in landscape ecological risks. However, the relationships between landscape ecological risk and its driving factors are poorly understood. In this study, the ADD was selected to construct landscape ecological risk index (ERI) values for 2000 and 2015. Based on a geographically weighted regression (GWR) model, the relationship between each of the normalized difference vegetation index (NDVI), land surface temperature (LST), digital elevation model (DEM), crop yield, population density (POP), and road density and the spatiotemporal variation in ERI were explored. The results showed that the ERI decreased from the periphery of the ADD to the centre and that high-risk areas were distributed in the ADD’s downstream region, with the total area of high-risk areas increasing by 86.55% from 2000 to 2015. The ERI was spatially correlated with Moran’s I in 2000 and 2015, with correlation of 0.67 and 0.72, respectively. The GWR model indicated that in most ADD areas, the NDVI had a negative impact on the ERI, whereas LST and DEM had positive impacts on the ERI. Crop yield, road density and POP were positively correlated with the ERI in the central region of the ADD, at road nodes and in densely populated urban areas, respectively. Based on the findings of this study, we suggest that the ecological constraints of the aforementioned factors should be considered in the process of delta development and protection.

scholarly journals Ecological risk assessment of geohazards in Natural World Heritage Sites: an empirical analysis of Bogda, Tianshan

2019 ◽  
Vol 11 (1) ◽  
pp. 327-340 ◽  
Author(s):  
Qin Liu ◽  
Zhaoping Yang ◽  
Hui Shi ◽  
Zhi Wang
Keyword(s):  
Risk Assessment ◽  
High Risk ◽  
Ecological Risk ◽  
Ecological Risk Assessment ◽  
World Heritage ◽  
Natural World ◽  
Low Risk ◽  
World Heritage Site ◽  
Heritage Site ◽  
Risk Areas

Abstract Ecological risk assessment plays an important role in avoiding disasters and reducing losses. Natural world heritage site is the most precious natural assets on earth, yet few studies have assessed ecological risks from the perspective of world heritage conservation and management. A methodology for considering ecological threats and vulnerabilities and focusing on heritage value was introduced and discussed for the Bogda component of the Xinjiang Tianshan Natural World Heritage Site. Three important results are presented. (1) Criteria layers and ecological risk showed obvious spatial heterogeneity. Extremely high-risk and high-risk areas, accounting for 13.60% and 32.56%, respectively, were mainly gathered at Tianchi Lake and Bogda Glacier, whereas the extremely low-risk and low-risk areas, covering 1.33% and 17.51% of the site,were mainly distributed to the north and scattered around in the southwest montane region. (2) The level of risk was positively correlated with the type of risk, and as the level of risk increases, the types of risk increase. Only two risk types were observed in the extremely low-risk areas, whereas six risk types were observed in the high-risk areas and eight risk types were observed in the extremely high-risk areas. (3) From the perspective of risk probability and ecological damage, four risk management categories were proposed, and correlative strategies were proposed to reduce the possibility of ecological risk and to sustain or enhance heritage value.

Assessment of Heavy Metal Contamination in Sediments along the Jiangsu Lagoon

2013 ◽  
Vol 641-642 ◽  
pp. 211-214
Author(s):  
Zhao Xiang Han ◽  
Zhen Zhu ◽  
Dan Dan Wu
Keyword(s):  
High Risk ◽  
Ecological Risk ◽  
Heavy Metal Contamination ◽  
Risk Index ◽  
Potential Ecological Risk ◽  
Low Risk ◽  
Moderate Risk ◽  
Ecological Risk Index ◽  
Risk Indices ◽  
Medium Risk

Abstract: In this study we have worked on the evaluation of heavy metal contamination in the sediments taken from the Jiangsu lagoon and thereby used the Enrichment factor (EF), Pollution load index (PLI), Geoaccumulation index (Igeo), Potential ecological risk index (PERI), Potential ecological risk index (PERI), Potential toxicity response index (PTRI) and Risk assessment code (RAC) and the methods of statistical analysis. The average EF of Zn is found to be less than 2, and the average EF of Cu, Cr, Cd, Pb and Ni are found to be greater than 2 in Jiangsu lagoon.The EF for Pb, Cd and Cr are higher along the Jiangsu lagoon and harbor, which reveals the anthropogenic contribution to the increased content of the surface sediments of the Jiangsu coast. PLI values calculated for Yancheng suggest that this zone is appreciably less impacted by metal pollutants than Nantong. Zn (Igeo(mean)<0), as unpolluted to moderately polluted with Cu (0<Igeo(mean)<1), moderately polluted with Ni (1<Igeo(mean)<2), moderate to strongly polluted with Cd (2<Igeo(mean)<3), and strongly polluted with Cr and Pb (3<Igeo(mean)<4). The potential ecological risk indices of Cu, Zn and Ni in 9 stations in Lianyungang coast were lower than 40, which indicated slight potential ecological risk of three metals in 9 stations.Potential ecological risk indices of Cu, Zn and Cd in 9 stations in Yancheng lagoon were lower than 40, which indicated slight potential ecological risk of two metals in 9 stations. The sediments show a medium risk for Cu with PERI value greater than 40 indicating a moderate risk from sediments across the entire Nantong region. The amount of Cu and Ni with low risk, while Cd with moderate, with high risk in Lianyungang coast. Cu, Zn and Cd with low risk, while Cr and Ni with moderate risk, but, the Pb with very high risk in Yancheng coast. Cu and Zn with low risk, Cr and Ni with medium risk, Pb,Cd with high risk in Nantong coast.

scholarly journals Identification of Ecological Risk Zoning on Qinghai-Tibet Plateau from the Perspective of Ecosystem Service Supply and Demand

2021 ◽  
Vol 13 (10) ◽  
pp. 5366
Author(s):  
Wei Shi ◽  
Fuwei Qiao ◽  
Liang Zhou
Keyword(s):  
Land Use ◽  
Ecosystem Services ◽  
High Risk ◽  
Ecological Risk ◽  
Temporal Pattern ◽  
Supply And Demand ◽  
Tibet Plateau ◽  
Risk Areas ◽  
Spatio Temporal ◽  
Qinghai Tibet Plateau

With the interaction of global change and human activities, the contradistinction between supply and demand of ecosystem services in the Qinghai-Tibet Plateau is becoming increasingly tense, which will have a profound impact on the ecological security of China and even Asia. Based on land cover data on the Qinghai-Tibet Plateau in 1990, 2005, and 2015, this paper estimated the supply capacity of ecosystem services using the value equivalent method, calculated the demand for ecosystem services using population density and economic density, established an ecosystem risk index based on the idea of an ecosystem service matrix to reveal the spatio-temporal pattern of the supply and demand of ecosystem services in the Qinghai-Tibet Plateau, and identified the potential ecological risk areas arising from the imbalance between supply and demand. The results showed that: (1) In terms of the spatio-temporal pattern of land use change, the desert area of the Qinghai-Tibet Plateau decreased the most with 26,238.9 km2, and other types of land use increased, of which construction land increased by 131.7%; (2) In terms of the supply and demand of ecosystem services, the Qinghai-Tibet Plateau was mainly dominated by low-level surplus areas, accounting for 64.0%, and the deficit in some areas has worsened significantly; and (3) In terms of division pattern of ecological risk areas, the Qinghai-Tibet Plateau presented characteristics of high risk in the east and low risk in the west. The high-risk area accounted for 1.1%, mainly distributed in the Huangshui Valley and the “One River and Two Tributaries” (Yarlung Zangbo River, Lhasa River, Nianchu River). The research results can provide reference for ecosystem management and policy formulation of the Qinghai-Tibet Plateau and have important significance for realizing the coupling and coordinated development of human–land relationship in Qinghai-Tibet Plateau.

scholarly journals Landscape ecological risk assessment and spatiotemporal change analysis in Yonghe County

2021 ◽  
Vol 237 ◽  
pp. 04038
Author(s):  
Jixuan Yan ◽  
Guang Li ◽  
Haiyan Wang ◽  
Meihua Zhang ◽  
Dongyuan Sun ◽  
...  
Keyword(s):  
Ecological Risk ◽  
Arable Land ◽  
Low Risk ◽  
Risk Level ◽  
Distribution Analysis ◽  
Risk Area ◽  
Change Analysis ◽  
Landscape Type ◽  
Risk Areas ◽  
Landscape Ecological

On the basis of land use data, combined with ArcGIS and fragstats4.2, the landscape ecological risk spatial mode and process feature of Yonghe county from 1980 to 2018 were analyzed. The results showed that: (1) from 1980 to 2018, the landscape pattern of Yonghe county changed obviously, the area of arable land and holt decreased, while the area of grassland, water and buildings grow a number. The conversion area between arable land and grassland is the largest. In Yonghe County, the fragmentation degree of landscape is on the rise, and the separation degree is also on the rise. The overall dominance of construction land is the largest, and the dominance of grassland is the smallest. (2) The landscape ecological risk level gradually subsided, the area of middle risk area decreased, and moderate risk areas are falling. From the spatial distribution analysis, the risk types of Yonghe County subsided from southeast to northwest. The high-risk areas were principally scattered in sangbi town and Jiaokou township. The main landscape type in this area was grassland, which was easily disturbed by human activities; the low-risk areas were principally scattered in Potou Township in the north and Yonghe County in the middle of the study area, and Woodland and buildings are the main landscape types land have strong anti-interference ability and low risk value.

scholarly journals Patch Pattern and Ecological Risk Assessment of Alpine Grassland in the Source Region of the Yellow River

2020 ◽  
Vol 12 (20) ◽  
pp. 3460
Author(s):  
Jia Liu ◽  
Jianjun Chen ◽  
Qiaoting Qin ◽  
Haotian You ◽  
Xiaowen Han ◽  
...  
Keyword(s):  
Spatial Distribution ◽  
High Risk ◽  
Ecological Risk ◽  
Yellow River ◽  
Source Region ◽  
Alpine Grassland ◽  
The Yellow River ◽  
Vegetation Types ◽  
Alpine Steppe ◽  
Risk Areas

The source region of the Yellow River (SRYR) is an important water conservation and animal husbandry resource in China. It is of great significance to understand the patch pattern and ecological risk of alpine grassland in the SRYR for ecological environment management. This study first used 12 unmanned aerial vehicle (UAV) aerial images and eight moderate resolution imaging spectroradiometer (MODIS) vegetation index product MOD13Q1 images from July to August in 2019 to extract alpine grassland patch patterns in the SRYR, then constructed an ecological risk model based on the landscape vulnerability index and landscape disturbance index, and finally combined spatial self-reliance correlation and semi-variance analysis methods to explore the spatial distribution of ecological risks. The results showed that the patch fragmentation degree (Pi), area weighted shape index (AWMSI), and separation degree (Si) of the four grassland types in the SRYR are ordered as follows: alpine steppe > degraded meadow > alpine meadow > swamp meadow. Moreover, the greater the fractional vegetation cover (FVC), the greater the landscape dominance index (DOi), and the better the ecosystem stability. The spatial difference of ecological risk in the SRYR shows a situation of low risk in the east (ERImin=1.5355) and high risk in the west (ERImax = 70.6429). High FVC was found in low and mild low risk areas where the vegetation types are mainly swamp meadow and shrub, while low FVC was found in high and mild high-risk areas where the vegetation types are mainly alpine steppe and degraded meadow. The spatial distribution of ecological risk of the SRYR has obvious positive spatial correlation (Moran's I = 0.863), the spatial aggregation distribution is distinct, and the local space has significant high-high aggregation and low–low aggregation phenomena. The results of this study reveal that patch characteristics have good indicative significance for alpine grassland ecological protection and should be considered in future studies. In addition, the ecological risk in the SRYR is relatively high, especially in the western region, which should be taken seriously in future ecological management and governance.

scholarly journals Integrating Ecosystem Function and Structure to Assess Landscape Ecological Risk in Traditional Village Clustering Areas

2021 ◽  
Vol 13 (9) ◽  
pp. 4860
Author(s):  
Sheng Liu ◽  
Ming Bai ◽  
Min Yao
Keyword(s):  
Land Use ◽  
High Risk ◽  
Ecological Risk ◽  
Land Use Changes ◽  
Ecosystem Structure ◽  
Study Region ◽  
Boundary Area ◽  
Ecological Risk Assessments ◽  
And Function ◽  
Landscape Ecological

Land use in traditional village clustering areas often exhibits slight dynamic changes; however, significant hidden ecological hazards may be present in local settlements. There is still a lack of dynamic ecological risk assessments for the corresponding classification-based prevention strategies and landscape ecosystem attributes’ enhancement. Based on the land-use changes, this study integrated the ecosystem structure and function to explore the characteristics of the landscape ecological risk in traditional village clustering areas. The clustering area of 24 national traditional villages in Songyang County of Lishui City in Zhejiang Province, China, served as the study region to evaluate and analyze the changes in the landscape ecological risk from 2010 to 2019. The results showed that the land-use transitions were subtle but dominated by changes from forest cultivated land, posing high risk and medium—high risk increased slowly in size. Additionally, significantly increased risks were located mainly in the boundary area of the five villages. Moreover, 22 settlements were found in the sensitive area with increased risks less than 600 m away. This assessment will provide a basis for traditional villages’ risk prevention and ecosystem protection.

scholarly journals Spatiotemporal Trends, Sources and Ecological Risks of Heavy Metals in the Surface Sediments of Weitou Bay, China

2021 ◽  
Vol 18 (18) ◽  
pp. 9562
Author(s):  
Qiuming Chen ◽  
Faming Huang ◽  
Anran Cai
Keyword(s):  
Heavy Metals ◽  
High Risk ◽  
Ecological Risk ◽  
Risk Index ◽  
Principal Component ◽  
Potential Ecological Risk ◽  
Ecological Risks ◽  
Spatiotemporal Trends ◽  
High Concentrations ◽  
Anthropogenic Contributions

Heavy metals are extremely harmful materials to marine ecosystems and human health. To determine the anthropogenic contributions and ecological risks in Weitou Bay, China, the spatiotemporal variations in the concentrations of heavy metals in surface sediment were investigated during spring 2008 and 2017. The results indicated that high concentrations of pollutants were generally located near the river mouths and along the coast of industrial areas. Principal component analysis indicated that heavy metal contents were mainly affected by industrial waste drainage, urban development, natural weathering and erosion, and interactions between organic matter and sulfides. The potential ecological risk assessment demonstrated that, in 2008, 82% of the sampling sites were at low risk, while 18% were at moderate risk. The situation had deteriorated slightly by 2017, with 73%, 18%, and 9% of stations in Waytou Bay at low, moderate, and very high risk, respectively. Cd was the most harmful metal, followed by Hg. These two elements accounted for more than 80% of the potential ecological risk index (RI) value. The present work analyzed the source of heavy metals, identified the major pollution elements and high risk areas, and provides guidance for pollution control and ecological restoration in Weitou Bay.

scholarly journals Comprehensive Analysis of Nitrogen Deposition in Urban Ecosystem: A Case Study of Xiamen City, China

2018 ◽  
Vol 10 (12) ◽  
pp. 4673
Author(s):  
Longyu Shi ◽  
Miao Zhang ◽  
Yajing Zhang ◽  
Bin Yang ◽  
Huaping Sun ◽  
...  
Keyword(s):  
High Risk ◽  
Nitrogen Deposition ◽  
Ecological Risk ◽  
Assessment Model ◽  
Atmospheric Nitrogen Deposition ◽  
Atmospheric Nitrogen ◽  
Residual Rate ◽  
Xiamen City ◽  
Risk Areas ◽  
The Impact

Atmospheric nitrogen deposition can supply nitrogen for ecosystems while posing a serious threat to ecological security. An assessment of the ecological risks caused by atmospheric nitrogen deposition is critical for urban sustainable development. Based on “Ecological Risk Analysis” and the “Driver-Pressure-State-Response (DPSR) framework,” this paper established a comprehensive ecological risk assessment model and assessed the ecological risk of nitrogen deposition in Xiamen City, China. The results showed that the risk from nitrogen deposition to the forest ecosystem is high due to the impact of nitrogen deposition on the residual rate of litter and survival rate of seedlings. The risks to freshwater and marine ecosystems were determined to be high and moderate, respectively, due to the promotion of eutrophication by nitrogen. The risk to farm ecosystems was low due to the impact on weeds. The proportion of high-risk areas in Xiamen City was 37.1%. Among the districts of Xiamen City, Tong’an and Xiang’an had the highest proportion of high-risk areas (48%) and low-risk areas (31.8%), respectively.

scholarly journals Flood-Landscape Ecological Risk Assessment under the Background of Urbanization

Water ◽  
2019 ◽  
Vol 11 (7) ◽  
pp. 1418 ◽  
Author(s):  
Yuan ◽  
Fang ◽  
Yan ◽  
Sui ◽  
Ding ◽  
...  
Keyword(s):  
Ecological Risk ◽  
Landscape Pattern ◽  
Large Scale ◽  
Risk Index ◽  
Structural Features ◽  
Watershed Scale ◽  
Landscape Pattern Metrics ◽  
Basin Scale ◽  
Landscape Ecological ◽  
Landscape Patches

The Hydrologic Modeling System (HEC-HMS) and statistical analysis method were used to analyze the relationship between flood eigenvalues (i.e., flood volume and peak flow) and landscape pattern metrics. Then, the flood-landscape ecological risk index (ERI_FL) was proposed and constructed to quantitatively assess the flood-landscape ecological risk (FLER). The semivariogram method was used to spatialize the ERI_FL values. Lastly, this study analyzed the spatial–temporal change of FLER at watershed scale and at sub-basin scale, respectively. Two historical landscape distributions (i.e., 2003 and 2017) of Qinhuai River basin were used to perform this study. The results showed that there were certain relationships between landscape pattern and flood eigenvalues, and for different landscapes, the response metrics and degrees were different. FLER increased as urbanization increased. FLER change magnitude had a positive relationship with urban land percentage change magnitude. The distribution of FLER and the distribution of FLER change both showed spatial differences at watershed scale. The structural features of landscape pattern had significant effects on regional floods. In the urbanization process, avoiding forming large-scale landscape patches, improving landscape abundance, and increasing contact area between different types of landscape patches were helpful to reduce the negative effects caused by the increase of urban landscape area on flood.

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