Exogenous relief agents - also called external agents or even from weathering and erosive agents – are the elements of nature that act in the transformation of the Earth's superficial modelling. They manifest themselves both in the wear of the existing relief on the surface and in the transport of sedimentary material to other areas, allowing the formation of new landscapes.
The main external agents of relief transformation are water, wind and climate. They help to modify the contours of natural landscapes and even act to model new terrestrial features. Together, these elements act in what we call weathering and also foster the process of erosion.
O weathering, also called weathering, consists of wear that results in physical degradation or chemical-biological decomposition of rocks. THE erosion, in turn, is nothing more than the result of the weathering process, in addition to also covering the transport of the generated sedimentary material and its deposition in other areas.
At waters promote weathering and erosion
in several possible ways. One example is rainwater, which slowly erodes the external volume of the relief and transports sediments (rock particles) to other areas. River waters also modify landscapes, and the same process occurs with sea water and coastal relief.The winds act, mainly, in the physical weathering of the external forms, mainly in those more acute rock formations. Slowly, over the millennia, the force of the winds gradually “breaks” the external features, taking the sediments to other areas. In some locations, the presence of winds is linked to the formation of sandbanks and also dunes in desert environments.
The climate mainly causes chemical weathering, in addition to the breaking of rocks through change of temperatures and modification of the expansion of different parts of the same structure of the relief.
In addition to the natural elements that constitute the relief transformation processes caused by exogenous agents of transformation, it is important to remember that human action can interfere and, mainly, accelerate such processes, especially the erosion. By removing vegetation or directly intervening in the composition of landscapes, human beings can have severe impacts on the natural order of behavior of the land relief.
By Me. Rodolfo Alves Pena
Source: Brazil School - https://brasilescola.uol.com.br/geografia/agentes-exogenos-relevo.htm