| 摘要: |
| 伴随泥沙淤积、水库运行、湖区围垦、岸线侵占和破坏等自然和人为因素的影响，洞庭湖区湖岸线已发生显著的改变，但是目前仍缺少遥感解译揭示其演变过程。利用1986—2022年多源遥感影像，通过归一化差异植被指数、最大值合成法以及大津法和目视解译相结合的阈值划分方法，识别并提取东洞庭湖、南洞庭湖和目平湖的植被带范围，进而分析洞庭湖区湖岸线的演变规律。通过栅格计算得到湖泊每年（相比于上年）植被带扩张和萎缩的面积，以及1986、1990、2000、2010和2020年植被带变化的空间分布。结果表明，洞庭湖区自然湖岸线呈现普遍扩张的趋势，并且不同位置在不同时期扩张和萎缩面积的占比不尽相同。东洞庭湖、南洞庭湖和目平湖的自然岸线所围水域面积分别缩减144.84、191.42和80.48 km2，缩减率分别为27.83%、39.20%和48.26%。藕池河东支尾闾汇入东洞庭湖内，通过数字岸线分析系统对其自然岸线进行统计分析表明，藕池河东支尾闾的自然岸线平均每年扩张距离为45 m，净岸线移动最大和最小距离分别为3281和386.93 m，线性回归的决定系数为0.68。总体而言，泥沙冲淤和水位变化是洞庭湖自然岸线变化的主要原因，人类采砂活动在局部区域造成了洞庭湖自然岸线的萎缩。 |
| 关键词: 洞庭湖 湖岸线 植被带 扩张萎缩 岸线演变 主控因子 |
| DOI： |
| 分类号: |
| 基金项目:国家重点研发计划项目(2023YFC3209502)；湖南省重大水利科技项目(XSKJ2019081-03)；湖北省技术创新重点研发计划项目(2023BCB110) |
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| Shoreline evolution of natural lakes in Lake Dongting area based on multi-source remote sensing interpretation |
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Bai Kuankuan,Li Zhiwei,Zhang Peng,Wang Zaiai,Zhao Wengang,Lu Hanyou
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State Key Laboratory of Water Resources Engineering and Management,Wuhan University
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| Abstract: |
| With the influence of natural and anthropogenic factors such as sediment deposition, reservoir operation, lake reclamation, shoreline encroachment and destruction, the lake shoreline of Lake Dongting area has changed significantly. However, the results based on remote sensing interpretation are still lacking to reveal its evolution processes so far. Based on the multi-source remote sensing imagery from 1986 to 2022, the range of vegetation zone in the east Lake Dongting, south Lake Dongting and Lake Muping were identified and extracted to analyze evolution processes of the lake shoreline using the threshold division methods, such as NDVI and maximum value composite combining with Otsu and visual interpretation. Through raster calculation, the annual expansion and erosion area relative to the previous year, as well as the spatial distribution in 1986, 1990, 2000, 2010 and 2020 of vegetation zone were obtained. The results show that the area of vegetation zone in Lake Dongting presented a general trend of expansion, and the proportion of expansion and erosion showed spatiotemporal differences. The water area enclosed by the natural shoreline decreased by 144.84, 191.42 and 80.48 km2, with a reduction rate of 27.83%, 39.20% and 48.26%, respectively. The analysis using the digital shoreline analysis system shows that the average annual moving distance of the natural shoreline in the tail zone of the east branch of Ouchi River entering the east Lake Dongting is 45 m. The maximum and minimum distance of the net shoreline movement is 3281 m and 386.93 m, respectively, and the coefficient of determination of the average linear regression is 0.68. In general, the sediment erosion and deposition and water lever change are the main driving force for the change of the natural lake shoreline in Lake Dongting, and sand mining activities have caused the erosion in the local area. |
| Key words: Lake Dongting lake shoreline vegetation zone expansion and retreat shoreline evolution dominant factors |
