Why do you think that the slopes or gradients are created by tectonic factors?
Slopes or gradients are created by tectonic factors because endogenic forces continuously elevate or build up parts of the earth's surface. These forces are mainly land-building forces that create relief variations on the earth's surface.
Due to variations in geothermal gradients and heat flow from within, along with differences in crustal thickness and strength, the action of endogenic forces is not uniform. This results in a tectonically controlled original crustal surface that is uneven, creating natural slopes and gradients from higher levels to lower levels.
These gradients are essential for mobility of surface materials, as all movements on the earth's surface occur due to gradients.
Explanation
The textbook explains that endogenic forces (tectonic factors) are land-building forces that continuously elevate parts of the earth's surface. Since the action of these forces is not uniform due to variations in geothermal gradients, heat flow, crustal thickness and strength, the original crustal surface becomes uneven. This unevenness creates gradients from higher to lower levels, which are essential for mobility and geomorphic processes like erosion, transportation and deposition.