The Effects Of Human Activities On Laizhou Bay Coastal Ecosystem And Its Early Warning

With the development and utilization of the coastal zone,the scale and intensity of nearshore human activities such as reclamation of land from the sea,coastal aquaculture,port and waterway construction are increasing,which destroys the coastal ecological environment and restricts the sustainable development of the coastal zone.The Laizhou Bay is one of the three bays in the Bohai Sea.It is rich in oil,natural gas,brine,mineral,and biological resources.In recent years,along with the port construction,industrial,and mining enterprises,the scale of reclamation has been increasing,the artificial coastline is growing rapidly,the natural coastline is almost disappeared,and the biodiversity and ecosystem health of coastal zone are facing severe challenges.Deeply study the types and dynamic changes of human activities in the coastal zone of the Laizhou Bay,and explore the effect of typical human activities on the coastal ecosystem,and carries on the early warning research of Laizhou Bay coastal zone ecosystem,which is of great significance to protect the coastal ecosystem and realize the sustainable utilization of coastal resources.Based on remote sensing images in different five periods and a large amount of socio-economic data,this study focuses on the intensity of human activities in the Laizhou Bay and exploration of its impact on the coastal ecosystem through four sections.First,an index system is constructed to dynamically evaluate the changes in human activity intensity from 1980 to 2018.Secondly,the effects of human activities on the coastal ecosystem are investigated from three aspects: the nearshore land subsystem,the shoreline,and tidal flat subsystem and the nearshore sea subsystem.Thirdly,the pressure-state-response(PSR)model is used to warn the security status of the coastal ecosystem.Finally,the countermeasures and suggestions are proposed for sustainable development in this region.The main conclusions are:(1)The intensity of human activities in the coastal zone of the Laizhou Bay has an obvious temporal and spatial variation from 1980 to 2018.A set of index system evaluating human activities in the coastal zone is constructed.The intensity of human activities in the coastal zone of this region increased significantly during the studied period,and with the largest increase from 2000 to 2010.The intensity of human activities in Shouguang city,Kenli of Dongying City remained at a high level.(2)Human activities have different impacts on the three ecological subsystems of the Laizhou Bay in the coastal zone.This study established a quantitative analysis model of the trade-off cooperative system relationship between human activities and the coastal ecosystem,which considers both the internal differences of the coastal ecosystem and the integrity of the ecosystem.The interaction between human activities and the ecosystem in the coastal zone of the Laizhou Bay gradually increased from 1980 to 2018.The coupling coordination degree between human activities and ecosystem has a good correlation with regional economic development.Where there is a higher the coupling coordination degree,there is the more obvious the cooperative relationship between human activities and the ecological system.The length of artificial shoreline and natural shoreline,the total area of shoreline and the area of salt-breeding ponds are main indicators associated with the intensity of human activities.With the increased intensity of human activities,the total length of the coastline increases,the natural coastline decreases,and the artificial coastline increases,resulting in a more tortuous coastline.The intensity of human activities is positively correlated with the area of tidal flats,the change rate of tidal flats,the area of salt ponds,and construction land.The nearshore sea area subsystem has not been strongly affected the coastal zone.The maximum comprehensive impact is 0.74,and the strongly affected area accounts for ? 30% of the total area in the study area.Most of the other areas are moderately and weakly affected areas,accounting for ? 60% of the total area.Among them,reclamation and port shipping are the most dominant human activities,followed by sewage discharge,mariculture and marine salt industry,which of them has a medium degree impact.(3)Comprehensive evaluation and early warning of coastal ecosystem in the Laizhou Bay based on Stress-State-Response and Extension Cloud Model.The Stress-State-Response(PSR)model was used to evaluate the comprehensive health status of the coastal ecosystem in Laizhou Bay under the influence of human activities.It was found that the health status of the coastal ecosystem in five periods were health,health,sub-health,unhealthy and sub-health respectively,and firstly showed a deterioration trend and then an improved trend.The extension cloud model is used to study the early warning of the Laizhou Bay coastal ecosystem in 2025 and2030.The results show that under the scenario of the continuation of the current situation,the ecological security level will be level ?(yellow warning)in 2025,with a trend of orange change,and the forecast results will be level ?(orange warning)in2030,but has a trend of improving to level ? yellow warning.Under the scenario of ecological environment protection,the ecological security levels of Laizhou Bay coastal zone in 2025 and 2030 are level ?,and the trend of improvement to level ?(blue warning).(4)Countermeasures and suggestions for sustainable development of coastal ecosystem in the Laizhou BayThe countermeasures and suggestions for the sustainable development of the Laizhou Bay coastal zone were proposed from three aspects: standardizing human activities in the coastal zone,protecting important ecologically sensitive areas and strengthening the monitoring and scientific research of the coastal zone ecosystem.To curb the deterioration trend of the coastal zone ecosystem of the Laizhou Bay and develop it sinto a benign and healthy state,the utilization intensity of coastal wetland in the coastal zone should be strictly controlled,strengthen the monitoring and scientific research of coastal ecological environment,and fundamentally reduce/solve the pressure of coastal ecosystem in this region.