Ecological Vulnerability Assessment Research Articles

Identification and assessment of the mudflat ecological vulnerability dominated by coastline evolution in Jiangsu

Coastlines have experienced profound alterations due to human disturbances and ocean dynamics against the backdrop of climate change and intensified anthropogenic activities. Significant modifications have occurred within the muddy coastal ecosystem, rendering it extremely susceptible to heightened levels of vulnerability. However, existing studies on coastal eco-environmental vulnerability have often overlooked crucial factors such as coastline erosion and siltation, particularly concerning coastline change. In this study, we assess coastline stability utilizing Landsat remote sensing imagery to investigate the vulnerability of coastal ecology alongside 24 economic and natural parameters, serving as indices for the Coastal Vulnerability Index (CVI) of the coastal eco-environment. Subsequently, we analyze the impact factors to vulnerability and predict trends in coastline change over the next 20 years to propose recommendations for sustainable development to safeguard the coastal eco-environment. Our findings reveal a trend towards coastline stabilization in Jiangsu, with significantly higher stability observed during 2010–2020 compared to 1985–2010. The overall CVI along the Jiangsu coast shows an downward trajectory over the past 15 years, primarily influenced by tidal action and coastal topography and geomorphology. Predictive modeling suggests Jiangsu coastline is bounded by the Sheyang estuary, with the coastline to the north dominated by stabilization and to the south dominated by siltation. Climate change, coupled with intensified human activities and future coastline alterations, may exacerbate vulnerability. Effective protection strategies for coastal ecosystems necessitate a comprehensive understanding of local natural conditions, resource availability, and socioeconomic dynamics. Governmental interventions should focus on reinforcing regulatory frameworks for coastal organism management, implementing coastal protection infrastructure, and enhancing supervision and management protocols for beachfront development, thereby fostering the sustainable management of muddy coastlines.

Mapping and assessment of ecological vulnerability to wildfires in Europe

BackgroundWildfires play a significant and complex role in ecosystems, influencing various aspects of their functioning and structure. These natural disturbances can positively and negatively impact ecosystems, shaping landscapes, nutrient cycles, biodiversity, and ecological processes. This study focuses on assessing and integrating the different factors that affect the ecological vulnerability to wildfires at the European scale. Our methodology follows three steps. Firstly, ecological values based on biological distinctiveness and conservation status were estimated to understand pre-fire conditions better. Secondly, we obtain vegetation’s coping capacity (or resistance) to the impacts of fire, considering the functional traits of plants and fire characteristics through a fire extreme scenario. Finally, post-fire recovery time was calculated by considering the species-specific recovery time, recovery starting time, growth recovery rate, and the environmental constraints affecting the optimal vegetation response. These three variables were combined using a dynamic model that assumed the change of value due to wildfires integrated throughout the recovery time.ResultsOur results indicate that the tundra biome emerges as the most ecologically vulnerable to fire, primarily due to its high ecological values and long recovery time, which outweigh its moderate coping capacity. Following closely, the temperate conifer forests also exhibit high vulnerability driven by their high recovery time, despite moderate ecological and coping capacity values. The boreal forests rank next, with moderate vulnerability due to their long recovery time and moderate coping capacity. The Mediterranean region, although having moderate ecological values and recovery time, shows a notable vulnerability influenced by lower coping capacity. The temperate broadleaf and mixed forests demonstrate relatively lower vulnerability owing to their balanced ecological values, moderate recovery time, and substantial coping capacity. Lastly, the temperate grasslands, savannas, and shrublands are the least vulnerable, benefiting from lower ecological values and the fastest recovery time, alongside moderate coping capacity, which collectively reduce their overall fire vulnerability.Furthermore, we found that coping capacity is the factor that most influenced ecological vulnerability to wildfires.ConclusionsThe study identifies key zones for European or national policies on fire prevention and post-wildfire regeneration. It offers insights into effective forest management and conservation policies, applicable to current conditions. Additionally, the methods can predict future ecological vulnerability to wildfires based on climatic and socio-economic trends.

Revealing various change characteristics and drivers of ecological vulnerability in the mountains of southwest China

Ecological vulnerability (EV) assessment is an important means of reflecting the evolutionary process of the local ecological environment, which is crucial for ecological security. The current EV assessment still faces challenges in comprehensively revealing its spatio-temporal change characteristics due to diversity, multi-scale complexity and non-linearity of ecosystems. In this study, we comprehensively revealed the spatio-temporal change features and driver mechanisms of EV in Yunnan Province (YP) using methods such as breaks for additive seasonal and trend (BFAST) and Geodetector. According to the findings, (1) the ecological vulnerability index (EVI) in YP decreased by 0.0265 on the raster scale between 2000 and 2018, and the ecological vulnerability level (EVL) was mainly dominated by level III. At the city scale, EVL in YP was dominated by level IV. At the basin scale, the average EV of the Jinsha River basin was much greater other basins. (2) The linear trend of EV in the YP mainly showed an insignificant decrease, mostly concentrated in the YP’s eastern region. The non-linear trend mainly showed a monotonous decrease, with the mutation time concentrated in 2009. The future persistence trend of EV under different coupling modes was dominated by anti-persistence decrease (Sen-MK + Hurst) and anti-persistence monotonous decrease (BFAST + Hurst), with an area percentage of 40.19 % and 25.13 %, respectively. (3) Gross primary productivity was the priority factor influencing YP’s EV (q = 0.4137). This study not only enriches the cases of EV assessment studies in the high mountain valley area but also bridges the gap of analysing the multi-spatial scale characteristics and change trends of regional EV.

Ecological vulnerability assessment and spatial-temporal variations analysis in typical ecologically vulnerable areas of China

Ecological vulnerability assessment is crucial for environment protection, ecological restoration and resource utilization. However, many former studies have limitations in the indicator system of the assessment, which were not comparable for different types of ecologically vulnerable areas. It is difficult to apply directly to the ecological vulnerability assessment of different types and in various regions. Aiming to solve these problems, the study proposed a well-established and comprehensive indicator system for ecological vulnerability assessment and conducted ecological vulnerability assessment application of five types of typical ecologically vulnerable areas of China based on remote sensing, meteorological, geographic and other data. The results show that the average EVIs value of Zhangbei County ranging from 0.525 to 0.559 are the highest among the five research areas during the four periods, followed by Zoige region and Xiamen bay. However, the region with the lowest average EVI value varies. In 2005 and 2015, it was Taihe County, while in 2010 and 2020, it was the Sanjiangyuan region. The variation of average EVIs in the five typical areas presents slight fluctuation and remains generally stable from 2005 to 2020. It indicates that the environmental protection measures and projects undertaken by the Chinese government in recent years have had a striking effect, curbing the trend of ecological environment deterioration.

Changes of ecological vulnerability in areas with different urban expansion patterns— A case study in the Yanhe river basin, China

Urban expansion has the potentiality to disrupt ecosystems and form highly fragile urban landscapes. However, studies investigating the impact of different urban expansion patterns on the ecological environments are relatively limited. Taking the Yanhe river basin, a typical basin in a loess region, as a case study, we developed an ecological vulnerability assessment system as well as assessed the main drivers of ecological vulnerability for different time periods (1990, 2000, 2010 and 2018). Additionally, we classified each urban expansion region into three different patterns according to the landscape expansion index, and analyzed changes in the ecological vulnerability under these three diverse patterns. Finally, the Kruskal-Wallis rank sum test was applied to compare the factors for the different changes in ecological vulnerability across different urban expansion patterns. Our investigation also aimed to elucidate the impacts of different urban expansion patterns on ecological vulnerability and identify key physical-social-economic-climatic drivers. The results indicate that the ecological vulnerability index (EVI) of the study area is decreasing gradually from the peak value of 0.459 in 2000 to 0.383 in 2018. Habitat quality index is found to be the most influencing factor, followed by aridity index and building density (mean q of 0.53, 0.46, and 0.42, respectively). Our study also reveals that the outlying expansion areas have the greatest increase in EVI at 0.38, with edge and infill expansions at 0.31 and 0.27, respectively. It is also found that when the overall environment is improving, the outlying expansion areas have the smallest decrease in EVI. Initial ecological vulnerability and key drivers may explain this difference. Therefore, results of this study indicate that the ecological impacts of diverse urban expansion patterns are significantly different, among which outlying expansions should receive prioritized attention.

Ecological Vulnerability Assessment of the Three Rivers Source Area Based on the Analytic Hierarchy Process

The Three Rivers Source, known as the “Water Tower of China”, is the birthplace of the Yangtze River, Yellow River, and Lancang River. The carrying capacity and environmental capacity of its ecological environment affect the ecological balance and resource utilization in the surrounding areas of the Three Rivers Source region, and are even closely related to the country’s ecology and economy. Taking the Three Rivers Source region as the research object, this paper selects six indicator layers and their corresponding 23 indicator items that affect the ecological vulnerability of the region. Nine professors in the field of ecological environment were invited to score and screen the indicators. Finally, a judgment matrix was established, and the Analytic Hierarchy Process (AHP) was used to comprehensively evaluate the ecological vulnerability of the Three Rivers Source region. The research results show that the most significant factor affecting the ecological vulnerability of the Three Rivers Source region is the reduction in ecological area, with a weight of up to 23.4%. This factor is followed by changes in terrain, growth and development environment, ground trampling effects, changes in vegetation structure, and potential changes in the integrity of natural vegetation. Their weights are 19.8%, 18.5%, 15.4%, 13.8%, and 12.3%, respectively. The weight of reduction in area is approximately 1.6 times higher than the potential impact on the integrity of natural vegetation. Changes in soil environment and terrain are the primary factors affecting ecological vulnerability. The lower the potential integrity of vegetation, the more fragile the ecosystem. Among the 20 research sites in the Three Rivers Source region, one has an extremely fragile ecological environment, and only six sites do not require excessive intervention. By analyzing and evaluating the different influencing factors of ecological vulnerability in the Three Rivers Source region, this study formulates corresponding ecological strategies to ensure the ecological restoration and sustainable development of the Three Rivers Source region. It provides a theoretical basis for the protection, management, and ecological construction of the Three Rivers Source region.

Ecological Vulnerability Assessment of the Qaidam Basin Based on SRP Model

Ecological Vulnerability Assessment of the Qaidam Basin Based on SRP Model

Geospatial assessment of ecological vulnerability of fragile Eastern Duars Forest integrating GIS-based AHP, CRITIC and AHP-TOPSIS models

Assessment of the ecological vulnerability of regional forests is extremely vital for easing the struggle for forest conservation. Therefore, the present study aims to delve into the ecological vulnerability of the Eastern Duars forest in the Indian sub-Himalayan region. The study employs three cutting-edge multi-criteria decision-making methods, including AHP, CRITIC, and AHP-TOPSIS methods, in which geo-environmental (elevation, slope, soil texture), hydro-meteorological (precipitation, temperature, waterbodies), vegetation index and anthropogenic (land use land cover, road, settlement) criteria are integrated, to assess ecological vulnerability. The vulnerability maps indicate that very high vulnerable areas comprise 0.05%, 0.01%, 23.96%, high vulnerable 19.72%, 17.51%, 41.52%, moderate vulnerable 63.45%, 49.66%, 29.49%, low vulnerable 16.70%, 30.82%, 4.10% and very low vulnerable 0.08%, 2.02%, 0.92% of area as per AHP, CRITIC, and AHP-TOPSIS method respectively. The highly vulnerable region is found in human-modified areas, where anthropogenic activities disrupt the natural ecological process, and deforestation is evident. Hence, careful strategic policies should be enforced regarding the restriction of anthropogenic activities, human habitation expansion, and changing climate to sustain the fragile Duars forest ecosystem. The inclusion of objective and hybrid criteria weighting methods, along with predominant knowledge-driven subjective weighting method, will promote the practice of comprehensive ecological vulnerability assessment.

Ecological Vulnerability Assessment and Spatiotemporal Characteristics Analysis of Urban Green-Space Systems in Beijing–Tianjin–Hebei Region

The evaluation and analysis of the ecological vulnerability of urban green-space systems are conducive to the sustainable development of urban green-space systems. Taking the urban green-space system in the Beijing–Tianjin–Hebei region in 2010, 2015, and 2020 as the research object, an ESSR model was first constructed, and a total of ten types of impact factors were integrated into the four dimensions of “Exposure, Sensitivity, State and Response”. The weight of the impact factors was objectively determined via spatial principal component analysis, and the ecological vulnerability of the urban green-space system was evaluated via superposition analysis; the evaluation’s results were graded. Moreover, the transfer matrix, center-of-gravity migration model, standard deviation ellipse, and spatial autocorrelation analysis were used to study the temporal and spatial variation characteristics of the evaluation results; then, the driving force of impact factors was analyzed based on a geographical detector. Finally, the rationality of the evaluation results was verified using the changing trend of the remote sensing ecological index (RSEI). The results show that the ecological vulnerability of the urban green-space system in the Beijing–Tianjin–Hebei region has decreased year by year for the past ten years. The distribution law of “Hebei surrounds Beijing and Tianjin” is presented in this space, and 2015 is the mutation node. In 2010, the moderately and severely vulnerable areas of Hebei surrounded the mildly vulnerability areas of Beijing and Tianjin. Moreover, in 2015 and 2020, the mildly vulnerable areas of Hebei surrounded the severely vulnerable areas of Beijing and Tianjin. Vulnerability expands slightly in the east–west direction and shrinks slightly in the north–south direction, and the center of gravity shifts towards Beijing year by year along the northeast direction. Moreover, the spatial distribution of vulnerability shows significant positive spatial autocorrelations and exhibits very obvious agglomeration. In addition, vulnerability is the result of the combined effect of various factors, and education degree, human disturbance index, and annual average precipitation are the dominant factors. The analysis results provide a reference for the effective application and sustainable development of urban green-space ecological functions.

Ecological vulnerability assessment and its driving force based on ecological zoning in the Loess Plateau, China

The imbalance of natural, social, and economic systems has engendered a multitude of environmental challenges, resulting in the increasingly vulnerable ecological environments. To mitigate the adverse effects of external disturbances on ecosystems, ecological vulnerability assessment (EVA) has emerged as a pivotal research domain in environmental science. Therefore, EVA of the Loess Plateau from 2000 to 2020 was conducted, utilizing a sensitivity-resilience-pressure (SRP) model based on ecological zoning, and identifying its driving factors. The findings revealed an overall ecological vulnerability index (EVI) of 0.53, signifying indicating a moderate vulnerability, and it exhibited a decreasing trend, with EVI of 0.58, 0.53, and 0.49, respectively. The EVI in the five ecological zones was: S5 (sandy desert region, 0.80) > S3 (agricultural irrigation regions, 0.66) > S1 (loess hilly and gully region, 0.52) > S4 (river valley plain region, 0.43) > S2 (Earth-rocky mountainous region, 0.38). Notably, a declining pattern in EVI was observed in S5, S1, and S3, while S2 and S4 experienced an increase. Moreover, the grade of EV reduced from the northwest to the southeast during all three periods, with a distinct positive spatial correlation and the presence of hot spots, sub-hot spots, sub-cold spots, and cold spots. Vegetation cover, humidity, and dryness were the main driving factors of EV, displaying significant interrelationships among all indicators. Finally, targeted protective strategies were proposed to enhance EV in different ecological zones of the Loess Plateau. Overall, EV in five ecological zones exhibited distinct spatiotemporal variation. This study offered a valuable framework of EVA applicable to arid areas, thereby promoting the ecological management and healthy development in vulnerable regions.

Sustainable development assessment of ecological vulnerability in arid areas under the influence of multiple indicators

The fragile ecosystems of arid areas are highly vulnerable, especially under the impact of human activities. Therefore, there is an urgent need to develop appropriate ecological vulnerability assessment models for these areas. In this study, Zhongwei City was taken as the study area. And a multi-indicator comprehensive assessment system was constructed using the optimized featured indicators-vulnerability scoping diagram (FVSD) model. The weights for each indicator were determined using the analytic hierarchy process-entropy weight (AHP-EW) method, leading to the creation of the ecological vulnerability map of Zhongwei City. The results showed that the overall ecological vulnerability of Zhongwei City is high and there is a significant spatial aggregation. There was obvious spatial heterogeneity in the distribution of vulnerability, with high vulnerability mainly concentrated in Haiyuan County, showing a decreasing trend from south to north. Watershed area index, annual average temperature, PM10 and annual afforestation index were the most important indicators affecting the ecological vulnerability, the fragile environmental conditions and human activities combine to shape the spatial heterogeneity of ecological vulnerability. The results of the study have important theoretical and practical implications in guiding ecological management of Zhongwei City. Moreover, the research framework can be replicated in different areas and is instructive for ecological vulnerability studies.

Corrigendum: Ecological vulnerability assessment based on remote sensing ecological index (RSEI): a case of Zhongxian County, Chongqing

Corrigendum: Ecological vulnerability assessment based on remote sensing ecological index (RSEI): a case of Zhongxian County, Chongqing

A new perspective on the whole process of ecological vulnerability analysis based on the EFP framework

Ecological vulnerability (EV) assessment is an effective method for evaluating ecological environments. However, there are few studies on the internal transformation process of EV and its influencing factors. As an important water source of China’s South-to-North Water Diversion Project, the southern Shaanxi has been gradually affected by different degrees of human influence in recent years. Therefore, the framework of “Evolution-Factor analysis-Prediction (EFP)” was established to analyze the evolution process from point to surface in this area, which was a new perspective that can be used to analyze the whole process of tracking ecological vulnerability evolution. The results showed that the ecological vulnerability had an obvious zonal distribution found significant ecological improvement, with an increase of 24.61% in ecological vulnerability level I and level II, and a decrease of 6.82% in level IV and level V. The causes obtained using the factor analysis model were mainly human factors, with the most significant factor being the industrial/agricultural output and its value exceeding 0.7. The center of gravity of ecological vulnerability shifted from the south to the north-east and then to the west by 17,390 and 20,206 m, respectively. This framework can better analyze the change process of regional ecological vulnerability, and is a feasible way to track the evolution of global environmental change.

Impact of grassland storage balance management policies on ecological vulnerability: Evidence from ecological vulnerability assessments in the Selinco region of China

The Selinco region is a highland grassland ecosystem with a unique lake system and diverse flora and fauna. However, it is highly vulnerable to degradation due to its high altitude and harsh climate. In recent years, the region has been subjected to increasing external pressures, including climate change, human activities, and natural disasters. Therefore, conducting an ecological vulnerability assessment is essential to ensure the sustainable development of the region. To achieve this, we performed a comprehensive integrated spatial principal component analysis (SPCA) of 12 representative ecological vulnerability indicators to assess the ecosystem of the region. This approach facilitated a comprehensive assessment of the ecological status of the region. Our study indicated that population and livestock density are the most important factors influencing environmental vulnerability. While the region has shown a trend of ecological recovery and stability over the past 20 years, some areas still experience ecological deterioration, emphasizing the importance of increasing efforts for to ecological conservation and restoration. Furthermore, we observed that different ecologically fragile areas have experienced varying degrees of transformation, underscoring the importance of more precise ecological conservation policies. At the county level, Nima and Shuanghu counties require focused attention and remedial measures to address severe ecological degradation, while other counties have demonstrated a trend towards ecological restoration, which could be attributed to the implementation of a balanced grass storage management policy that mitigates the impact of human activities. Therefore, further research is essential to determine the persistence of ecological trends and to identify long-term conservation and sustainable use solutions.

Ecological vulnerability assessment of coral islands and reefs in the South China Sea based on remote sensing and reanalysis data

Coral reefs are ecosystems that are highly vulnerable to external environmental impacts, including changes associated with ocean acidification and global warming. Assessing the vulnerability of coral reef growth environments over large areas of the sea is a difficult and complex process, as it is influenced by many variables. There are few studies on environmental vulnerability assessment of coral islands and reefs in the South China Sea. It is therefore particularly important to understand the environmental sensitivity of corals and how coral communities respond to changes in climate-related environmental variables. In this study, indicators were selected mainly from natural environmental factors that hinder the development of coral reefs. The sea surface temperature (SST), sea surface salinity (SSS), wind velocity (WV) and direction, sea level height (SL), ocean currents (OC), and chlorophyll concentration (Chl) of coral reefs in South China Sea Island were integrated to calculate the coral reef environmental vulnerability region. In a GIS environment, Spatial Principal Component Analysis (SPCA) was used to develop sensitivity models and evaluate the ecological vulnerability of coral reefs. Based on the Environmental vulnerability indicator (EVI) values, the study area was classified as 5 grades of ecological vulnerability: Potential (0.000–0.577), Light (0.577–0.780), Medium (0.780–0.886), Heavy (0.886–0.993) and Very Heavy (0.993–1.131). Sensitivity models identified regional gradients of environmental stress and found that some coral reefs in western Malaysia and southwestern Philippines have higher vulnerability. Meanwhile, the study found that the reefs of Paracel Islands and Macclesfield Bank areas of medium vulnerability. Future use of high-precision data from long time series will allow better estimates of site-specific vulnerability and allow for the precise establishment of marine protected areas so that the ecological diversity of coral reefs can be sustained.

A reliable ecological vulnerability approach based on the construction of optimal evaluation systems and evolutionary tracking models

Ecological vulnerability assessment is an effective means to monitor ecosystem stability, and its application has been an emerging hotspot. Although some progress has been made in the study of ecological vulnerability, there are few studies on the accuracy of the evaluation index and the tracking of the evolution process. Therefore, this study discussed the impact of the improved ecological vulnerability assessment index system and spatial scale on the ecological vulnerability of the target area, and conducted a confirmatory analysis of it. Taking Weinan City, a typical city in the Yellow River Basin as the research object, the evolution tracking model of ecological vulnerability was established, and the internal relationship between the dimensions of impact factors and ecological vulnerability index (EVI) was analyzed. The results showed that (1) the correlation between EVI and NDVI of the optimized index system (e) (ISe) was −0.793, and the R-value of linear fitting was 0.63, which indicated that the optimized evaluation results were closer to the actual situation. (2) From 1999 to 2019, the overall ecological condition of Weinan was positive, with the distribution characteristics of low EVI in northern and southern mountain cities and high EVI in central plain cities. (3) Hierarchical transformation of EVI in the combination area where ecological vulnerability remained stable and degraded accounted for 75.24%, indicating that the overall evolution direction of ecological vulnerability changed to a good direction. The results can provide an effective way to optimize and validate the ecological vulnerability assessment system and track the evolution of ecological vulnerability effectively.

Long-term ecological vulnerability assessment of Indian Sundarban region under present and future climatic conditions under CMIP6 model

Vulnerability assessment of ecosystem bestows an idea about the ecosystem health and its ability to resist environmental stress. Indian Sundarban region situated at the southwest part of Ganga-Brahmaputra-Meghna delta has been under constant threat of frequent climate hazards and long-term climate change. Various attempts have been made for vulnerability assessment of this mangrove ecosystem focusing only on static non-temporal variables. The present work hypothesises that mangrove ecosystems are highly adaptive and respond to the changing environment by various natural resilience strategies at the ecosystem level. So, a better understanding of the dynamics of mangrove ecosystem will provide an idea about the state of vulnerability for this ecosystem. The present study uses 16 parameters to create exposure, sensitivity and adaptive capacity risk indices and constructs the vulnerability status for the Indian Sundarban. The results showed that the sea-level rise will happen between 0.7 m to 0.9 m under baseline climate conditions. The CMIP6 multi-model ensemble showed that the future minimum temperature for the region will go up to 29.48 °C, thereby reducing the max and min temperature difference for the region. The fuzzy AHP-based vulnerability assessment revealed that the western Sundarban is more prone to climate vulnerability. The island-like Surendranagar, Lothian, and West-Ajmalmari are extremely vulnerable. The proximity to human habitat will play an important role in climate change sensitivity to the Sundarban region. The time series analysis of mangrove forests showed the Mann-Kendall ‘τ’ value varies between 0.82 to −0.83. The central Sundarban forests area shows a varying degree of forest health deterioration. The assessments from the present study and the maps will help the environmental and risk-managers to identify the regions needing more climate change adaptation strategy.

Ecological Vulnerability and Ecological Risk Assessment of Shanghai Section of Hangzhou Bay North Shore

Vulnerability research and ecological risk assessment of coastal ecological environment are of great significance for the temporal and spatial evolution process and trend of coastal zone. In this paper, using the 4-phase GF-1 remote sensing data, the landscape fragility index and landscape artificial disturbance intensity index of the Shanghai section of the north bank of Hangzhou Bay are calculated, and the temporal and spatial variation characteristics and the response to human activities are analyzed. The prediction based on Kalman filtering is used. The area of the landscape vulnerability level of the Shanghai section of the north shore of Hangzhou Bay in 2022. The results show that: (1) The lower fragile area is the dominant type of vulnerable area between 2013 and 2016, and the low-vulnerable area rises to the dominant type in 2016-2018, and the area of higher and high vulnerable areas is on the rise, and the vulnerable areas in 2018-2019 The change is slower than the previous stage. High-level vulnerable areas continue to spread, mainly from urban to suburban, inland to coastal, land to port. (2) The landscape change in the study area has a significant response to human activities, and there is a significant positive correlation between landscape fragility and landscape artificial disturbance intensity. (3) Based on the Kalman filter method, the results of predicting the level of vulnerable areas in each landscape in 2022 show that the area of the low vulnerability level area and the higher vulnerability level area has increased from the previous moment, and the lower vulnerability level area and The area of the medium vulnerability level has increased from the previous moment, and the area of the high vulnerability level has increased from 2018, which is lower than that in 2019.

Change of the spatial and temporal pattern of ecological vulnerability: A case study on Cheng-Yu urban agglomeration, Southwest China

China's urban economy has developed rapidly over the decades, and the Cheng-Yu urban agglomeration has become one of China's four typical urban agglomerations, with a large population and a high level of economic development. However, the conflict between humans and the environment is becoming increasingly prominent together with economic development. In order to protect the ecological environment in urban areas, thus scientific understanding and assessment of ecological vulnerability are beneficial to establishing regional conservation measures, and serve as a key means to maintain environmental health. Based on the “Sensitivity-Resilience-Pressure” (SRP) model, this study considered remote sensing, geographic and statistical data to construct an evaluation system for regional ecological vulnerability. In addition, the coupled AHP (Analytic hierarchy process)-Entropy weighting model was proposed to obtain the weight of each evaluation indicator and analyze the spatio-temporal distribution characteristics of the ecological vulnerability of the study area during 2000–2020. The changes and the divergence pattern were depicted by the transfer matrix, dynamic degree and spatial auto-correlation. The results indicated that the ecological vulnerability of Cheng-Yu urban agglomeration is mainly mild and moderate, with an overall high distribution in Chongqing and Chengdu, while low in the central and north zone (e.g., Ziyang, Mianyang). It is consistent with the distribution of HH (High-High) and L-L (Low-Low) clusters, respectively, having a significant positive spatial correlation. In particular, the severely vulnerable area increased from 7059 km2 in 2000 to 23553 km2 in 2020, with an increased rate of 233.66 %. Combining the transfer matrix and dynamic degree, it was found that the ecological environment underwent a rapid deterioration followed by a slow recovery. This study provides a scientific reference for the ecological policy making which serves sustainable urban development.

Ecological vulnerability assessment of natural oasis in arid Areas: Application to Dunhuang, China

Oasis vegetation contains a variety of ecological functions and can quickly indicate changes in the environment. According to the vegetation dynamics of natural oasis, this study constructed a natural oasis ecological vulnerability assessment model (NOEV) The model is based on Pressure-Sensitivity-Resilience framework, combined with redundancy analysis, minimum cumulative resistance model, and ecological risk sensitivity index to effectively assess the ecological vulnerability of natural oasis. The results showed that human activities, represented by the expansion of farmland and population growth, were the main factors affecting the vegetation dynamics of natural oasis in the last 30 years, and their contribution to the change of vegetation area is 42.08%. In the temporal dynamics, a serie of economic and environmental policies implemented by the government after the 21st century have promoted the recovery of vegetation. Vulnerability decreased on the whole oasis but increased in some local areas during 2005–2020. In the spatial dynamics, the transition zone of vulnerability from high to low occurred, it a distance of approximately 30 km from an artificial oasis located also in the area. We suggest that the governments should set up an ecological buffer zone in this area and implement different environmental protection policies inside and outside the buffer zone. Few vulnerability assessment models have been constructed for oasis ecosystems, and the NOEV model constructed in this study helps to formulate more direct and effective policy recommendations for the government's ecological protection and restoration work.