Les vessants dels rius creen unitats, de Yorkshire a Catalunya

 

https://share.google/jWsNaa8HSLq67rgBu 

Yorkshire’s eight main rivers ridden from source to mouth in 2018–2020. The Swale, Ure, Nidd, Wharfe, Aire, Calder, Don and Derwent all flow ultimately into, or become, the Ouse not far from York. Their dales and valleys cover the county. https://e2e.bike/e2e-bike/yorkshire-ridings/ 

https://riusdecatalunya.cat/segre-5/   Des de Nyer, a la Granja dels Coms (fermedescoums), pensant que el Segre organitza la Cerdanya -i neix a França.