Slope development | Geomorphology | Principle Of Geography

 

Geomorphology

Principle Of Geography

Geography Complete Study Material

(Paper - I)

Slope Development

                        The physical landscape is an assemblage of slopes. Geomorphologists for long been intrigued by the study of the origin and form of slopes, it posed a major challenge to the study of landforms. Various theories and models were formulated to provide a rational explanation to its origin and form but all had their own flaws. Despite the fact that slope constitutes the core of landform study, it has not received due attention and largely remained neglected. The study of slopes faces a number of challenges. It becomes difficult to determine its nature, the rate of operation of the processes, and its effect on the slope. It is also very difficult to mark the whole trajectory of slope development and trace changes in its form with the passage of time. In a landform study, there are two aspects that have always remained in the focus- the form and the process. The term ‘form’ indicates the morphology of a given region at a given time. The different shape a landform assumes is the focus of the study while ‘process means the actual operation of different agents which bring about changes in the physical environment. These agents are many and they vary in terms of their role in different regions. The process includes agents such as soil creep, surface wash, weathering, etc.

                  Slopes are produced by both Endogenetic and Exogenetic processes. Based on these two processes they have been broadly divided into – Endogenetic Slopes and Exogenetic slopes.

Endogenetic Slopes

These slopes originate due to the processes which originate within the earth. Different earth movements lead to the formation of folds, faults, rift valleys, etc. These slopes are also referred to as tectonic slopes. Fault scarps are often associated with faults and rift valleys. The volcanic eruption which is also an outcome of the endogenetic process going on inside the earth results in the formation of new features. Volcanic Eruptions cause the accumulation of lava and pyroclastic materials and give rise to different kinds of volcanic hills, plateaus, and cones. The features formed due to the volcanic eruptions or tectonic processes undergo modification by subaerial processes resulting in various slope forms.

Exogenetic slopes 

These slopes are an outcome of external processes originating at or near the earth’s surface. Processes like weathering, mass wasting, erosion, and deposition play key role in fashioning a landscape. These processes consistently operate upon the surface and regularly create and modify slope forms.