Suppose you are standing at the top of a hill after a heavy rainfall. As the rainwater falls, it begins to flow down through different small paths, merging with other water streams until it finally reaches a large river or lake. This entire process — where water finds its way through various channels and collects…
Various theories have been proposed to describe the mechanisms of slope development, each offering a unique perspective on how slopes transform. From W.M. Davis’ concept of slope decline, which emphasizes a gradual reduction in slope steepness, to W. Penck’s slope replacement model, which focuses on the accumulation of debris at the base, these theories highlight…
Let’s imagine you are standing on a hilltop, looking down at the valley below. The land between where you stand and the valley floor isn’t flat—it slopes downward at various angles. This angular inclination of terrain between hilltops and valley bottoms is what we call a slope. But why does this happen? What shapes these…
Imagine you are watching a cricket match. The batsman, initially full of energy, starts playing aggressively, hitting boundaries with ease. As the innings progresses, fatigue sets in, and the once-powerful strokes become slow nudges. Just when you think he is about to getting out, he drinks an energy booster and suddenly regains his power, smashing…
Imagine you are standing atop a vast plateau, looking at rivers carving their way through valleys, shaping the land ever so gradually. Now, visualize this transformation as a slow but continuous process, much like an artist chiselling a sculpture over centuries. This is the essence of the Davisian Cycle of Erosion, a concept that describes…
Denudation Chronology (DC) is a concept developed primarily by the British School of Geomorphology, with further contributions from W.M. Davis in the American School. It focuses on reconstructing the history of denudation (weathering and erosion) in a given region over geological time. Unlike theories emphasizing endogenetic processes (such as tectonics), DC prioritizes exogenic forces that…
Imagine a riverbed that remains stable for years and then suddenly experiences a major flood, causing rapid erosion and shifting sediment downstream. Unlike the classical idea that landscapes evolve gradually and continuously, S.A. Schumm proposed that denudation occurs in episodic bursts, leading to periods of rapid erosion followed by long phases of deposition. This irregular…
Imagine a river flowing through a valley. Over time, erosion wears down the hills, but if the forces acting on the landscape—like uplift, river flow, and climate—remain constant, the overall shape of the land doesn’t change significantly. J.T. Hack, an American geomorphologist, proposed this idea in his Dynamic Equilibrium Theory, arguing that landscapes are in…
Imagine Earth as a battlefield where two mighty forces constantly struggle for dominance—tectonic forces that uplift land and denudational forces that wear it down. American geomorphologist Marie Morisawa proposed a model to explain how landscapes evolve based on this continuous interaction between upliftment and erosion. To understand her model, picture the Himalayas. These mountains are…
To understand any geomorphological model, we must first ask: Where did the thinker observe this pattern?L.C. King based his geomorphic theory on the landscape patterns of South Africa, especially the arid, semi-arid, and savanna regions. This environment shaped his thinking. The Four Elements of a Hillslope Before we dive into the evolution of landscapes, let’s…
