The typical Japanese river maintains a vegetation‐suppressive effect on riparian habitats. During recent decades, most Japanese rivers have encountered extensive human‐induced alterations, and over time, the rivers have been transformed from unvegetated to vegetated. The lower Tedori River, which is a representative case of this phenomenon, is located in a region that exhibits signs of global climate change. According to quantitative analyses of sediment, the river corridor has historically reached an equilibrium since the prohibition of heavy sediment extraction activities, and the water discharge is stable because of dams. The contemporaneous vegetation encroachment was observed in a historical imagery survey and the vegetation dynamics of the river reach for the past 18 years were analysed to identify forcing hydro‐climatic variables. The normalized difference vegetation index (NDVI) was adopted for the surveillance of vegetation dynamics, and multiple regression analysis was employed to evaluate its relationship with predictor variables. River water level was the strongest determinant of NDVI, with both Pearson correlation and standardized β coefficients of −0.405, while air temperature was next, with values of 0.363 and 0.288, respectively. These findings were supported by the spatial distribution of temporally advancing vegetation patches determined using the aerial imagery and pixel value maxima of NDVI bands. In addition, the development of vegetation patches will presumably give rise to more pro‐vegetation surroundings in the riparian zone through reciprocal linkages with hydrogeomorphic processes. These objective predictions may help inform the proactive planning for river and coastal management.

中文翻译：

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在水文地貌改建的河流环境中河岸植被的长期遗留

典型的日本河流对河岸生境保持了植被抑制作用。在最近的几十年中，大多数日本河流都经历了人为引起的广泛变化，并且随着时间的流逝，河流已从无植被转变为无植被。代表这种现象的特多里河下游位于显示全球气候变化迹象的地区。根据对沉积物的定量分析，自从禁止进行大量的泥沙提取活动以来，河道历史上就达到了平衡，并且由于大坝，排水稳定。在历史图像调查中观察到同期的植被入侵，并分析了过去18年河段的植被动态，以识别强迫的水文气候变量。采用归一化植被指数（NDVI）进行植被动态监测，并采用多元回归分析评估其与预测变量的关系。河流水位是NDVI的最强决定因素，皮尔逊相关系数和标准β系数均为-0.405，而空气温度次之，分别为0.363和0.288。这些发现得到了使用航空影像和NDVI波段的像素值最大值确定的临时前进植被斑块的空间分布的支持。另外，植被斑块的发展可能通过与水文地貌过程的相互联系而在河岸带带来更多的植被环境。