What is the process that tends to build up the land surface by deposition of solid material in its lower areas, known as ?

The process of building up the land surface through the deposition of solid materials, such as sediment, in lower areas or depressions is known as aggradation. In geomorphology, weathering and erosion lead to the simultaneous processes of 'degradation' (wearing down) and 'aggradation' (building up) [1]. Aggradation occurs when the supply of sediment exceeds the transport capacity of a system, causing materials to settle and fill up depressions [1][t1]. This typically happens in river systems, deltas, and alluvial fans where stream velocity decreases, reducing the water's transporting power and forcing the load to settle [c2][c3]. While 'abrasion' and 'attrition' are types of erosional wear, and 'agglomeration' refers to the collection of particles into a mass, aggradation specifically describes the increase in land elevation due to sediment accumulation [t1][t3].

Sources

1. [1] Physical Geography by PMF IAS, Manjunath Thamminidi, PMF IAS (1st ed.) > Chapter 16: Fluvial Landforms and Cycle of Erosion > 16. Fluvial Landforms and Cycle of Erosion > p. 197