Original sentence: Its northern part, which averages around 250m above sea level, the landscape is marked by several river valleys, as Weiße Elster, Zwickauer Mulde and the Göltzsch have their spring in the Vogtland, while the Saale flows through Bavaria and Thuringia in the west of Vogtland
Edited sentence: In its northern part, which averages around 250m above sea level, the landscape is marked by several river valleys, as the Weiße Elster, the Zwickauer Mulde and the Göltzsch have their spring in the Vogtland, while the Saale flows through Bavaria and Thuringia in the west of Vogtland