1990—2013年中国东北地区湿地生态系统格局演变遥感监测分析

全球变化背景下,湿地生态系统极具敏感性和脆弱性。论文以Landsat TM/ETM+/OLI和国产环境卫星影像为数据源,重建1990、2000和2013年3期东北地区湿地生态系统分布格局;通过将东北地区划分为六大重要湿地分布区,探讨了区域天然湿地与人工湿地的分布和动态空间差异性及其驱动因素。结果表明：1990、2000、2013年东北地区湿地面积分别为11.75×10⁴、10.57×10⁴、10.41×10⁴ km²,湿地率分别为9.45%、8.50%、8.38%。湿地分布具有明显的地域特征,大兴安岭湿地区是最主要的天然湿地分布区,除水田外的人工湿地主要分布在辽河三角洲湿地区。1990—2013年东北地区湿地面积损失严重,损失面积为1.34×10⁴ km²,湿地相对损失率为11.4%,天然湿地相对损失率为14.3%,主要转化为耕地。三江平原湿地区的湿地率下降最明显,天然湿地损失面积为9 935.2 km²;松嫩平原湿地区人工湿地面积增加最明显,增加 1 141.9 km²。气候变化影响叠加人类活动干扰背景下,沼泽湿地是对全球变化响应最显著的湿地类型,损失面积为16 091.4 km²。气候要素和人文因子对湿地影响具有明显的空间差异性,人类活动的变化更加能够主导东北地区湿地面积的变化。

Monitoring the Evolution of Wetland Ecosystem Pattern in Northeast China from 1990 to 2013 Based on Remote Sensing

With the background of global change, wetland has great sensitivity and vulnerability. In order to investigate the dynamics of the spatial characteristics and heterogeneity of natural and human-made wetlands in Northeast China, the ecosystem pattern of six important wetland regions in the study area in 1990, 2000 and 2013 were rebuilt based on satellite images of Landsat TM, ETM+, OLI and Chinese HJ. Results indicated that the area of wetlands in Northeast China in 1990, 2000 and 2013 was 11.75×10⁴, 10.57×10⁴ and 10.41×10⁴ km², respectively. The distribution of wetlands had obvious regional features. There are more natural wetlands in the Greater Khingan Mountains wetland region, while there are more human-made wetlands in the Liaohe Delta wetland region. Notable loss of wetlands was observed in Northeast China during 1990-2013 (11.4% of wetland, 14.3% of natural wetland). Most of the disappeared wetlands were converted to croplands. The most significant decrease of wetland area was observed in the Sanjiang Plain with a loss of 9 935.2 km² for natural wetlands, however significant increase of human-made wetland area was observed in the Songnen Plain, with an increase of 1 141.9 km². There were clearly spatial differences in the impacts of climatic and human factors on the wetlands. Based on the changing trends of wetland, climate and human factors, human activities were the leading driving force for the losses of wetlands.