Headward erosion is a process in which the upper part of a stream or river valley erodes back towards its source, effectively lengthening the river. This process is significant in understanding river dynamics, landscape evolution, and the development of drainage networks.
Source Ferguson, R. I., & Werritty, A. (1983). Headward Erosion in a Small Scottish Catchment. Earth Surface Processes and Landforms, 8(4), 391-395.