The Landscape Pattern Change And Ecological Security Evolution Resrarch Of Guangxi Beibu Gulf Coastal Wetland

Guangxi Beibu gulf coastal wetland is an important wet area in Guangxi,which has important ecological functions and provides a natural ecological barrier for the coastal economic development of Guangxi Beibu Gulf.The local wetland ecosystem has an irreversible impact because of the irrational development and utilization of coastal wetlands with the rapid economic development of Guangxi.It is of great significance for the rational utilization of coastal wetland resources and ecological environment construction in Guangxi to study the spatial-temporal evolution of landscape pattern and ecological security status.Based on RS and GIS technology to acquire the remote sensing image(2000,2005,2010 and 2016)and establish the classification system for the coastal wetland information extraction,the spatial and temporal evolution of landscape pattern in the study area was analyzed by land use transfer matrix and landscape pattern index,and analysis the driving force.A total of 20 indicators were selected from the three aspects of environmental pressure,resource environment state and human response to construct the ecological security evaluation index system of Guangxi Beibu Gulf coastal wetland based on the PSR model framework,to evaluate the ecological security of Guangxi Beibu Gulf coastal wetland in 2000,2005,2010 and 2016 respectively.The results show that:(1)During the 2000 to 2016 period,the area of tidal flats,water in the category of natural wetlands reducing were 23.24 ? squared and 58.7 ? squared,and the area of mangrove was decreases and then increased because of a lot of artificial mangrove planting and native mangrove ecological restoration in late period;In the category of artificial wetland,the area of aquatic farm has been increased 6.35 ? squared,and the area of paddy field is greatly reduced,covers an area of 103.78 ? squared;The biggest change in area is construction land with the area increase of 170.61 ? squared in all types of landscape,which increase comes mainly from urban construction of sea reclamation;The second change in area is aquatic farm,whose main increase source is paddy field;The speed of change in area of wetland was increases at first and then slows down.The variation of coastal wetland landscape is affected by human disturbance,the heterogeneity of landscape decreases,the spatial distribution tends to be balanced,and the instability of landscape structure increases.(2)Natural factors such as climate and hydrology are the basis of landscape changes of various coastal wetlands.Human factors such as regional development level,population growth,economic development and improvement of urbanization level are the main driving factors of landscape changes in study regional wetlands.(3)The ecological security of Guangxi Beibu Gulf coastal wetland presented a declining trend on the whole from 2000 to 2016.And it was declining obviously during the 2005 to 2010,and then the declining trend of ecological security of coastal wetland was alleviated from 2010 to 2016 with the increasing protection of coastal wetland.In the three change areas of ecological security of coastal wetland,the overall condition is better in Fangchenggang section,Qinzhou section,and Beihai section.Guangxi Beibu Gulf coastal wetland ecological security level from grade I to grade ? changes,the ecological safety of Guangxi Beibu Gulf coastal wetland is threatened,which need to take corresponding measures to protect the security of ecological.(4)According to the research on the change of regional landscape pattern and its driving factors,ecological security status and influencing factors,suggestions are put forward from the three aspects of coastal wetland resource management,protection,and ecological restoration,so as to maintain or improve the ecological security status of Guangxi Beibu Gulf coastal wetland and promote the harmonious development of human and coastal wetland.