1956年以来洞庭湖盆的演变  

Evolution of Dongting Lake Basin Since 1956

作　　者：徐琪 瞿毅然 朱博渊 柴元方 XU Qi;QU Yi-ran;ZHU Bo-yuan;CHAI Yuan-fang(School of Hydraulic and Environmental Engineering,Changsha University of Science&Technology,Changsha 410114,Hunan Province,China;Key Laboratory of Water-Sediment Sciences and Water Disaster Prevention of Hunan Province,Changsha 410114,Hunan Province,China;The Bartlett School,University College London,London WC1E 6BT,UK;Faculty of Geographical Science,Beijing Normal University,Beijing 100875,China)

机构地区：[1]长沙理工大学水利与环境工程学院,湖南长沙410114 [2]水沙科学与水灾害防治湖南省重点实验室,湖南长沙410114 [3]伦敦大学学院巴特莱特学院,伦敦WC1E 6BT [4]北京师范大学地理科学学部,北京100875

出　　处：《中国农村水利水电》2023年第11期119-124,130,共7页China Rural Water and Hydropower

基　　金：国家自然科学基金资助项目(52209079);流域水循环模拟与调控国家重点实验室开放研究基金项目(IWHR-SKLKF202211);湖南省自然科学基金项目(2021JJ40607)。

摘　　要：1956年以来洞庭湖盆经历了萎缩和扩容的历史过程,为分析各历史阶段变化原因和预测变化趋势,根据1956-2019年洞庭湖水系水沙和湖盆水面面积、湖容实测资料开展研究,基于分离变量法重点识别泥沙淤积、湖盆沉降、湖区围垦及洞庭湖水系采沙对湖容变化的贡献比例。结果表明:1956-2019年洞庭湖水面面积减小1247.59 km^(2),其中东洞庭湖水面面积萎缩最为严重,1956-1980年湖区围垦是洞庭湖水面面积减小的主要因素,1980年以后洞庭湖水面面积趋于稳定。三峡水库蓄水前(1956-2002年)入湖沙量及出湖沙量均持续减少,泥沙淤积率约为70%;三峡水库蓄水后(2003-2019年),入湖沙量大幅减少,泥沙淤积率降至14%。湖盆沉降、湖区采沙与泥沙淤积对湖容的影响存在抵消效应,洞庭湖盆目前仍处于缓慢的构造沉降中,平均沉降速率约3 mm/a;2003年以后随着采沙活动进行,洞庭湖萎缩速率有所减缓。1980年以前湖容减小,湖区围垦、泥沙淤积和湖盆沉降对湖容增大的贡献比例分别为-92.7%、-13.2%和5.9%;1980年以后湖容经历了由减小至变大的过程,整体为减小,1981-2002年泥沙淤积、湖盆沉降的贡献比例分别为-107.6%和7.6%,2003-2019年泥沙淤积、湖盆沉降及采沙的贡献比例分别为-11%,24.8%和86.2%。三峡水库蓄水后湖盆沉降速率大于泥沙淤积速率,同时湖区采沙为三峡水库蓄水后湖容变化控导因素,随着新一轮采沙规划(2023-2027年)实施,洞庭湖将呈现扩张趋势。Since 1956,the Dongting lake basin has experienced a historical process from shrinkage to development.To investigate the reason behind its evolution during each historical stage and predict its evolution trend,we work out this study based on data of water-sediment dis⁃charge,lake-basin water surface area and lake capacity during 1956-2019,in which contribution ratios of sedimentation,lake basin subsid⁃ence,reclamation and sand mining on lake-capacity variation are identified using the variable separation method.Results show that the lake-basin water surface area decreased by 1247.59 km2 during 1956-2019,in which the shrinkage of the east lake basin was the most se⁃vere,and reclamation within the lake basin was the major driving factor during 1956-1980,whereas the lake-basin water surface area be⁃came stable after 1980.Both sediment input and output continuously declined before the impoundment of the Three Gorges Dam(1956-2002),with a rough sedimentation ratio of 70%in the lake.However,sediment input experienced a remarkable reduction after the impound⁃ment(2003-2019),with the sedimentation ratio falling to 14%.There was an offset effect among lake-basin subsidence,sand mining and sedimentation when they altered the lake capacity.At present,the lake basin is still in a slow tectonic subsidence,with an average rate of 3 mm/a.As sand minning proceeds,the lake shrinkage slows down.Before 1980,the lake capacity decreased,with contribution ratios of recla⁃mation,sedimentation and tectonic subsidence were-92.7%,-13.2%and 5.9%.However,after 1980,the lake capacity witnessed a shift from declination during 1981-2002 to augment during 2003-2019 and a net declination,with contribution ratios of sedimentation and tecton⁃ic subsidence were-107.6%and 7.6%during 1981-2002 and those of sedimentation,tectonic subsidence and sand mining were-11%,24.8%and 86.2%during 2003-2019.Considering the higher rate of tectonic subsidence than sedimentation after the impoundment of the Three Gorges Dam and the dominance of sand mi

关 键 词：洞庭湖 水面面积 湖容 驱动因素 贡献比例 

分 类 号：TV142[水利工程—水力学及河流动力学]