东北地区湿地遥感监测与景观分析

分析东北地区湿地的时空变迁特点,可为东北地区湿地资源的合理利用、合理分配湿地资源、制定东北地区湿地保护和利用相关政策提供科学依据。以1975年MSS遥感图像、2013年CBERS遥感图像为数据源,借助于地理信息系统软件,采用人机交互目视解译的方法,并根据所建立的遥感解译标志,在遥感图像中解译出东北地区湿地信息;引入马尔科夫转移矩阵、重心迁移、景观格局等多种分析方法,探讨东北地区湿地时空动态变化特点。结果表明:近40年来东北地区湿地面积总体呈减少趋势,其中沼泽湿地面积减少24 769.9 km~2、河流湿地面积减少6 753 km~2、人工湿地面积增加22 017.4 km~2;非湿地与湿地各类型间转化明显,其中,沼泽湿地向非湿地、人工湿地转化显著,非湿地向沼泽湿地、人工湿地转化显著;湿地重心总体向南偏西方向迁移36.5 km,其中,人工湿地重心向北偏东方向迁移354.7 km、沼泽湿地重心向南偏西方向迁移261.4 km。景观格局分析显示,东北地区湿地总体向破碎化、多样化与不规则化发展。

Remote Sensing and Landscape Analysis of Wetlands in Northeast China

As one of the three major types of ecosystems on earth, wetlands provides important ecological services such as regulating climate, conserving water, purifying wastewater, degrading environmental pollutants and protecting species diversity. In this study, MSS remote sensing images of Northeast China wetlands from 1975 and CBERS images from 2013 were analyzed using GIS software and human-machine interactive visual interpretation. The spatial-temporal changes of the wetlands were then explored using the Markov transfer matrix, barycenter migration model and characterization of landscape patterns. The wetland area of Northeast China has decreased over the past 40 years, from 86017.0km2 in 1975, to 76707.3km2 in 2013. There was an obvious migration between non-wetland and wetland; meadow wetlands decreased significantly by 24769.9km2 and river wetlands by 6753km2, while constructed wetlands increased by 22017.4km2 and lake wetlands by 920.1km2. The barycenter of constructed wetlands migrated 354.7km to the northeast while the barycenter of meadow wetlands migrated 261.4km to the southwest, giving an overall wetland barycenter migration of 36.5km to the southwest. The spatial migration of wetlands in Northeast China is due to overexploitation of wetland resources in the north of Wudalianchi City and east and north of Jiamusi City at the end of 20th century, resulting in a significant decrease of meadow wetlands and a significant increase in constructed wetlands. In the study area, the total wetland area decreased while the number of wetland patches increased from 12,110 to 16,907. The patch density increased from 0.141 ind/km2 to 0.220 ind/km2 while the average area of the wetland patches decreased from 7.103km2 to 4.537km2. The Shannon diversity index of the wetland landscape pattern increased from 1.774 to 1.945 and the Shannon evenness index increased from 0.790 to 0.926. Overall, the landscape pattern of wetlands in Northeast China displayed increased fragmentation, diversification and irregularity. These results provide a scientific basis for the protection, restoration and rational utilization of wetland resources in Northeast China. It also provides a technical reference for the coordination and development of the regional ecological environment.