近30年来高邮湖(含邵伯湖)自然水域面积变化及其影响因素

Changes in Water Area of Gaoyou Lake (including Shaobo Lake) and the Influencing Factors in the Past 30 Years

  • 摘要: 湖泊水域面积变化特征反映气候与人类活动对湖泊生态系统结构与功能的影响,对湖泊健康评价与水生态修复有重要指导价值.以1988-2015年8期Landsat TM/ETM+遥感影像为数据源,综合运用目视解译法与比值阈值法提取了研究区高邮湖(含邵伯湖)及其围网养殖区的边界信息,分析了研究区水域面积变化特征及其影响因素.结果表明:①1988-2015年研究区自然水域面积呈现前期持续缩小、近期部分恢复的阶段性变化趋势.其中,1988-2000年自然水域面积缓慢缩减,平均减小速率为4.08 km2/a;2000-2011年迅速缩减,平均减小速率为12 km2/a;2011-2015年迅速增长,自然水域面积增加108 km2;1988年自然水域面积最大(716 km2),2011年最小(535 km2),2015年部分恢复(643 km2).②1988-2015年流域内年均降水量先减后增,年均气温逐渐升高.年均气温升高与自然水域面积变化具有相关性(R2=0.472);年均降水量则与自然水域面积变化无明显关联(R2=0.118).③1988年和1992年研究区内未见明显的围网养殖,2000年围网养殖区面积仅为45 km2,2011年最大,达199 km2.2000-2009年和2009-2015年围网养殖区面积平均增长速率分别为15.56和9.00 km2/a;北部湖区围网养殖集中,自然水域面积变化最为显著,东西湖区次之.研究显示,1988年以来,年均气温和围网养殖对高邮湖自然水域产生了显著影响,湖区北部湿地侵占严重,湿地生态屏障功能下降.

     

    Abstract: The change of lake water area demonstrates the impact of climate and human activities on the structure and function of the lake ecosystem, which therefore becomes an important ecological indicator for lake health assessment and water restoration. The characteristics of natural water area change under the impact of aquaculture and climate change in the past 30 years in Gaoyou Lake (including Shaobo Lake), a typical shallow lake in East China, as well as various influencing factors were analyzed. Using GIS technology, images of the Landsat TM/ETM+ remote sensing from 1988 to 2015 were set up as the data source. The boundary information of Gaoyou Lake (including Shaobo Lake) and its breeding area was extracted by visual interpretation and ratio threshold methods. The results showed that:(1) In the past 30 years, the natural water area of Gaoyou Lake tended to progressively reduce in the early stage and partially recovered in the following years:the largest area appeared was 716 km2 in 1988, the smallest area was 535 km2 in 2011, and 643 km2 in 2015. From 1988 to 2000, the average natural water area decreased by 4.08 km2/a, whereas from 2000 to 2011 the average decrease rate was 12 km2/a, yet from 2011 to 2015 it increased by 108 km2. (2) From 1988 to 2015, the annual amount of precipitation in the catchment decreased first and then increased. The annual average temperature increased gradually in relation to the change of natural water area in Gaoyou Lake (R2=0.472); There was no significant correlation between precipitation and the change of water area (R2=0.118). (3) The enclosed aquaculture lake area was neglectable before 2000, which was only 45 km2 in 2000, while the largest area of 199 km2 appeared in 2011. The average growth rate of aquaculture area was 15.56 km2/a from 2000 to 2009 and 9.00 km2/a from 2009 to 2015. The aquaculture was concentrated in the northern lake area, where the natural water area consequently shrank most significantly, followed by the eastern and the western lake. Since 1988, temperature and fishery aquaculture have a significant impact on the natural waters of Gaoyou Lake that the shoal in the northern part of the lake has been heavily invaded, and the ecological barrier function of wetlands has greatly declined.

     

/

返回文章
返回