1988—2017年洪泽湖自然湖面变化特征及其影响因素

Characteristics and influencing factors of natural lake level change of Hongze lake in 1988—2017

以Landsat TM/ETM+遥感影像作为数据源,基于GIS和RS技术,利用年变化率和湖泊变化强度指数等方法定量分析1988—2017年洪泽湖湖面变化趋势及特征,通过收集1988—2018年洪泽湖地区的气象数据以及人工围养数据,结合当地实际深入研究湖面变化主要原因。①1988—2017年,洪泽湖自然湖面整体上呈萎缩-平稳-萎缩的态势,近30年共减少125.81 km2,相对萎缩速率为9.88%,强度变化指数(Q)为-0.34。相比而言,第三阶段(2009—2017年)减少较为显著,第一阶段(1988—2000年)次之,第二阶段(2000—2009年)较稳定,其Q分别为-0.61、-0.24和-0.13;从区域位置上来看,洪泽湖面积变化主要集中在湖区西部,其次是东北部。②气温与降水量因子均与湖面变化呈线性相关,气温在1988—2018年总体升高,促使蒸发量增大;其降水量的变化也导致湖泊补给量下降。③洪泽湖沿岸的养殖业造成自然湖面萎缩,1988—2017年人工养殖面积扩大了20倍,直接导致自然湖面损失5.0%。④湖泊阶段变化中,政策变化以及洪涝灾害也是影响洪泽湖自然湖面变化的驱动因子。1988—2017年洪泽湖自然湖面基本呈逐步萎缩的态势,气象因素、政策变化以及洪涝灾害情况导致湖面的萎缩,但围网养殖是导致其变化的主要原因。

Using Landsat TM/ETM+remote sensing image as data source,based on GIS and RS technology,using annual change rate and lake change intensity index and other methods to quantitatively analyze the change trend and characteristics of Hongze lake in 1988—2017.By collecting the meteorological data and artificial conservation data of Hongze lake in 1988—2018,combined with the local actual situation,the main causes of area change were studied in depth.①From 1988 to 2017,the natural lake surface of Hongze lake showed a trend of shrinking-stable-shrinking.In the past 30 years,it decreased 125.81 km2,the relative shrinking rate was 9.88%,and the intensity change index(Q)was-0.34.In comparison,the third stage(2009—2017)decreased significantly,followed by the first stage(1988—2000),and the second stage(2000—2009),which was relatively stable,with Q of-0.61,-0.24 and-0.13,re⁃spectively.In terms of regional location,the change of Hongze lake area was mainly concentrated in the west of the lake area,followed by the northeast.②Both temperature and precipitation factors are linearly related to the change of lake level,and the overall increase of temperature in 1988—2018 promotes the increase of evaporation;The change of precipitation also leads to the decrease oflake sup⁃ply.③From 1988 to 2017,the area of artificial aquaculture expanded 20 times,which directly led to the loss of 5.0%of the natural lake.④During the change of lake stage,policy change and flood disaster are also the driving factors that affect the change of the natu⁃ral lake surface of Hongze lake.From 1988 to 2017,the natural lake surface of Hongze lake basically showed a trend of gradual shrink⁃ing.Meteorological factors,policy changes and flood and waterlogging disasters caused the lake surface to shrink,but purse seine farming was the main reason for its change.