Different levels of human pressures have modified the dynamism and the morphological pattern of most riparian environments worldwide. Among the anthropogenic agents, flow regulation by dams, gravel mining; artificial land use and land cover changes together with climate change are the most frequently studied. Medium and short term geomorphological adjustments and riparian vegetation cover changes have been frequently studied by using a variety of methodological approaches, with the diachronic analysis of orthophotographs as the most common starting point. The main objective of this research is to assess the spatio-temporal evolution of geomorphological conditions and riparian vegetation cover along a 38 km-long reach of the Tagus River, analysing the last 70 years, in order to understand the main drivers leading to those changes. To that purpose, a complementary diagnosis has been carried out by combining different approaches: (1) Simple geomorphological indicators, (2) Specific geomorphic indexes, (3) Landscape metrics and (4) Transition matrices, together with the analysis of flow discharges. Results show that River Tagus has suffered a narrowing process (67.7%) along the entire study period (1946–2014) close to a decrease in width ratio of 2.1 m/year. However, the narrowing trend was not stable along the entire period, with the most dramatic reduction happened between 1956 and 1975 with a decrease ratio around 7.1 m/year for that subperiod. At the same time, woody riparian vegetation, grass and shrubs covers decreased in comparison with 1946 photo while agriculture land increased within initial riparian zone. By combining different approaches, we note the progressive impoverishment of geomorphic status that is more severe when we consider the area (-49%) of fluvial landforms instead of their number (-26%), in parallel with the fragmentation and complexity pattern found for both vegetated and bare gravel bars according to landscape patchiness analysis. Our results show that geomorphic status in the 4 sub-reaches have decreased, although in the case of sub-reach 1 and 4 the response presents a delay with the more important decrease occurring from 1975 to 1999. This geomorphological evolution is explained by the synergic combination of different human pressures along time. Initially, flow regulation by large dams influenced this evolution, but water-transfer since 1979 and floodplain occupation by farmland activities were more relevant with the time. River dynamism, figured out as the amount of area subject to rejuvenation (i.e., evolution toward more pioneer stages) and succession processes (i.e., evolution toward more mature stages), was reduced more than a half along the period 1946–1975, while it completely changed after 1975 where they became close to 10% of the initial dynamism. Thus, our results show by the combination of different approaches that River Tagus channel has become immobilized, reduced with a simplified morphology and its riparian vegetation lost its dynamism converted into a mature wood.

不同水平的人类压力已经改变了全世界大多数河岸环境的动力和形态模式。在人为因素中，大坝的流量调节，砾石开采；人工土地利用和土地覆盖的变化以及气候变化是研究最频繁的。经常使用各种方法学方法来研究中短期地貌调整和河岸植被覆盖度变化，以正射照片的历时分析为最常见的起点。这项研究的主要目的是评估塔霍河38公里长的河段的地貌条件和河岸植被覆盖的时空演变，分析最近70年，以了解导致这些变化的主要驱动因素。为此，通过组合不同的方法进行了补充诊断：（1）简单的地貌指标，（2）特定的地貌指标，（3）景观指标和（4）过渡矩阵，以及流量排放分析。结果表明，塔霍河在整个研究期间（1946–2014年）经历了变窄过程（67.7％），其宽度比减小了2.1 m /年。但是，缩小趋势在整个时期内都不稳定，最大的下降发生在1956年至1975年之间，该时期的下降率约为7.1 m /年。同时，与1946年的照片相比，木质的河岸植被，草和灌木的覆盖面积减少了，而最初的河岸带内的农业用地却增加了。通过结合不同的方法，我们注意到，当我们考虑河流地貌的面积（-49％）而不是其数量（-26％）时，地貌状态的逐步恶化更为严重，同时发现植被和裸露的砾石的破碎和复杂性模式根据景观斑块分析。我们的结果表明，尽管在1级和4级子区域中，响应出现了延迟，并且从1975年到1999年出现了更重要的下降，但4个子区域的地貌状态有所下降。随时间变化的不同人类压力的组合。最初，大型水坝的水流调节影响了这一演变，但自1979年以来的调水和农田活动对洪泛区的占用都与时间相关。河流动力，计算出，在1946年至1975年期间，受复兴的区域（即，朝着更多的先驱阶段发展）和继承过程（即，朝着更成熟的阶段发展）的面积减少了一半以上，而在之后1975年，他们的动能接近最初的10％。因此，我们的结果表明，通过不同方法的组合，塔霍河河道已被固定化，通过简化的形态而减少，其河岸植被失去了其动力并转化为成熟的木材。