Why Ganga Brahmaputra basin has varied topography?

The Ganga-Brahmaputra basin has varied topography due to its geological history, which includes the collision of the Indian and Eurasian tectonic plates, leading to the uplift of the Himalayas. This collision creates diverse landforms such as mountains, hills, and plains within the basin. Additionally, the region is shaped by erosion and sediment deposition from the rivers, resulting in fertile alluvial plains and intricate river systems. The interplay of these geological and hydrological processes contributes to the basin's rich topographical diversity.