基于景观格局变化的海岸带生态风险评价——以辽宁省瓦房店市为例

Ecological Risk Assessment of Coastal Zone Based on Landscape Patterns Change:A Case Study of Wafangdian County,Liaoning Province

文章利用RS和GIS技术手段对辽宁省瓦房店市1990—2015年的变迁过程进行监测,得出各历史时期的土地利用变化信息。将各类土地利用信息与景观生态学相结合,利用景观格局破碎度、景观分离度、景观优势度作为指标构建景观损失指数,并利用景观组分的面积比重构建海岸带生态风险指数。基于ArcGIS和Fragstats软件平台,通过空间采样和插值方法得到区域生态风险的空间分布,据此重构了瓦房店市1990—2015年的生态风险值变化过程。监测表明,1990—2015年期间,耕地、林地和滩涂呈减少趋势,水域和建设用地逐年增加,其他类型变化幅度不大。虽然耕地所占总面积比例由45.37%减少至37.23%,但一直是瓦房店最主要的景观。25年间瓦房店生态安全总体呈下降态势,1990—2015年6时段的生态风险年平均值分别为0.211 9、0.200 3、0.203 2、0.194 9、0.209 7和0.209 1。在时间维度,1990—2005年和2010—2015年生态安全度下降明显;在空间维度,瓦房店市海岸带的李官镇-三台满族乡和谢屯镇-炮台镇的生态风险度高,西杨乡、东岗镇和驼山乡生态风险由极高降为高或中,生态安全度有所提高。研究表明,人口和社会经济发展是影响瓦房店市景观格局变化的主要因素,该区域未来海岸带要实现可持续开发必须要进行科学的规划。

According to the remote sensing survey of Wafangdian＇s coastal zone changes during the past 25 years,the monitoring historical data of regional remote sensing was disposed by RSand GIS techniques,and the land utilization information during various periods of time was classified by combining with research purpose.From ecological risk definition,combining all kinds of information of land use and landscape ecology,landscape fragmentation,landscape isolation and landscape dominance were conducted as the index to build landscape damage index,while the ecological risk index was constructed by the coastal zone proportion of landscape composition.Based on software platform of ArcGIS and Fragstats,spatial distribution of regional ecological risk could be worked out by space sampling and interpolation method;and then reconstructed the ecological risk value process of Wafangdian from 1990 to 2015.Research showed that,during 1990—2015,land,woodland and beaches had shown a decreasing trend,with increasing water and other types of construction little changes.The total cultivated land area ratio decreased from 45.37% to37.23%,but had been the most important landscape.Comparing the ecological risk values of 1990 and 2015,an overall decline in Wafangdian coastal zone ecological security status was concluded.The annual average values of the ecological risk of 1990—2015 were：0.211 9,0.200 3,0.203 2,0.194 9,0.209 7 and 0.209 1.In the time dimension,the ecological security degree of 1990—2005 and 2010—2015 decreased significantly.In the space dimension,the coastal zone of Wafangdian City,ecological risk degree of Liguan-Santai and Xietun-Paotai＇s was high,ecological risk degree of Xiyang,Donggang and Tuoshan decreased from extremely high or higher to middle or low,ecological safety was improved.The results showed that the population and social economic development were the main factors that influenced the landscape pattern change of Wafangdian City,a scientific plan to deal with it should be carried out by the government.