The dynamic responses of wetlands to upstream water conservancy projects are becoming increasingly crucial for watershed management. Poyang Lake is a dynamic wetland system of critical ecological importance and connected with the Yangtze river. However, in the context of disturbed water regime in Poyang Lake resulting from human activities and climate change, the responses of vegetation dynamics to the Three Gorges Dam (TGD) have not been investigated. We addressed this knowledge gap by using daily water level data and Landsat images from 1987 to 2018. Landsat images were acquired between October and December to ensure similar phenological conditions. Object‐oriented Artificial Neural Network Regression for wetland classification was developed based on abundant training and validation samples. Interactions between vegetation coverage and water regimes pre and post the operation of the TGD were compared using classification and regression trees and the random forest model. Since the implementation of the TGD in 2003, Poyang Lake has become drier, especially during the dry season. A more rapid plant growth rate was observed post TGD (44.74 km² year⁻¹) compared to that of the entire study period (12.9 km² year⁻¹). Average water level for the antecedent 20 days most significantly affected vegetation before 2003, whereas average water level for the antecedent 5 or 10 days was more important after 2003. The impoundment of the TGD after the flood season accelerated the drawdown processes of Poyang Lake, and the rapidly exposed wetlands accelerated vegetation expansion during the dry seasons, resulting in shrinkage and degradation of the lake area. This study deepens our knowledge of the influences of newly developed dams on lakes and rivers.

中文翻译：

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大坝运行导致水文连通湿地植被动态的加速

湿地对上游水利项目的动态响应对于流域管理变得越来越重要。yang阳湖是具有重要生态意义的动态湿地系统，与长江相连。然而，在human阳湖由于人类活动和气候变化而引起水情混乱的情况下，尚未研究植被动力学对三峡大坝（TGD）的响应。我们通过使用1987年至2018年的每日水位数据和Landsat图像来解决这一知识缺口。Landsat图像是在10月到12月之间获取的，以确保相似的物候条件。基于丰富的训练和验证样本，开发了用于湿地分类的面向对象的人工神经网络回归。使用分类和回归树以及随机森林模型比较了TGD手术前后植被覆盖度与水分状况之间的相互作用。自从2003年实施TTG以来，Po阳湖变得更加干燥，特别是在旱季。TGD后（44.74 km²年^-1）相比，整个研究期间（12.9 km ²年^-1）。前20天的平均水位在2003年之前对植被的影响最大，而前5天或10天的平均水位在2003年之后更为重要。汛期后TGD的蓄水加速了Po阳湖的水位下降过程，并且快速暴露的湿地加速了干旱季节的植被扩张，导致湖泊面积缩小和退化。这项研究加深了我们对新开发的水坝对湖泊和河流的影响的认识。