基于土地利用/覆盖变化的中国大陆沿海地区生态状况评价

Assessment of ecological conditions over China's coastal areas based on land use/cover change

研究沿海地区土地利用变化及其对生态状况的影响,对于了解区域生态状况演变乃至全球变化具有重要意义.本研究以中国大陆沿海地区1980、1990、1995、2000、2005、2010和2015年7期土地利用/覆盖、高程及基础地理信息数据为关键数据源,利用生态等级指数法,对10个省级行政单位56个城市的生态状况进行综合评价,分析其时间动态演变和空间分异特征,深入探讨了高程分异及海陆梯度对我国大陆沿海地区生态状况的影响.结果表明:1980—2015年间,我国大陆沿海地区生态状况基本稳定,呈现逐步恶化、局部改善的特征.我国大陆沿海地区生态状况大致以杭州湾为界,呈南高北低的空间分异特征.大陆沿海地区生态等级指数高程分异显著,海拔<10 m的地区生态状况相对较差,海拔<30 m的区域在研究时段内生态状况的恶化趋势最为明显;研究区生态状况随着海拔的升高而增加,且海拔>400m区域的生态状况在研究时段内呈现逐步好转的趋势.大陆沿海地区生态等级指数在海陆方向上亦存在梯度特征,自陆向海呈现高-低-高模式,距海10 km处生态状况变化最为显著,且随着距海距离的增加而降低.

Studying the changes of land use and its impacts on ecological condition in coastal areas is of great significance for understanding the evolution of the regional ecological conditions and even global change. In this study,the study area encompassed 10 provincial administrative units of China＇s coastal areas,covering a total of 56 cities. Based on the land use and land cover data in1980,1990,1995,2000,2005,2010 and 2015 and the corresponding elevation data,we assessed ecological conditions and its temporal dynamic evolution and spatial differentiation characteristics with the ecological grade index method. The effects of the elevation differentiation and land-sea gradient on the ecological condition in China＇s coastal areas were analyzed. The results showed that the ecological conditions of China＇s coastal areas were basically stable and deteriorated on the whole although partially improved from 1980 to 2015. With Hangzhou Bay as a boundary-belt,ecological conditions in southern parts were better than that in the northern parts. The ecological grade index differed significantly with the variation of elevation. The areas with elevation below 10 m were in relatively poor ecological condition,and the regions below 30 m had the most obvious changes of ecological conditions. Moreover,the ecological conditions increased with elevation,with a gradual turnaround trend of improvement at above 400 m. There was a gradient characteristic of the ecological grade index in China＇s coastal areas,showing a high-low-high pattern from land to sea. Furthermore,the maximum value of ecological condition changes appeared at a distance of 10 km to the coastline,and the values decreased with the increasing of distance to the coastline.