Geographical Thought by Neetu Singh Geography is defined as the description of the earth. The concept and definition of the subject changed with the passage of time in response to the changing philosophy and approaches used by geographers –

• Geography is described as Mother of all sciences (Sir Patrick Geddes) • Geography is the science which deals with the art of map making (Ptolmey, Eratosthenase) • Geography is description of the earth which deals with the inter-relationship of phenomena that exist together (Alexander Von Humboldt) • Geography is branch of science which deals with globe in all its features, phenomena and relations as an independent unit and shows the connection of this unified whole with man and man’s creator (Ritter) • Geography is a chorological science (Alfred Hettner) • Modern Geography has been described as a science, concerned with the inter-relationship of man and his environment, with the earth as home of man (L.D. Stamp) • Geography is concerned to provide accurate orderly and rational description and interpretation of variable characters of earth’s surface (Hartshorne)

Geomorphology – is important branch of physical and systematic geography. • P.G. Worcester defined it to be the subject of interpretative description of the relief features of earth's surface. • A.L. Bloom defined it as the discipline which describes systematic analysis of landscapes and the processes involved for their evolution. • Evolution of it is marked in work of Greek Roman scholars like Herodotus, Aristotle, and Strabo who presented simple geomorphic observation as fluvial action. • Herodotus (delta formation of Nile), Aristotle (phenomena of land expansion in shallow sea), Strabo (regression and transgression of seas) • Arab Scholar Ibn Sina gave idea of differential rate of erosion due to variable structure. Al Masudi described stages of development of landforms. • Among Europeans, Leonardo da Vinci, Buffon De Saussure presented processes of fluvial action. • James Hutton established concept of present is the key to the past – doctrine of uniformitarianism. John Play Fair and Charles Lyell were the followers (18th century contributors) • Ramsay and Richthofen attempted the study of glaciation of geological past (19th century contributors) • The era of 20th century began with systematic and scientific explanation in geomorphology. • J.W. Powell, G.K. Gilbert and G.E. Dulton were pioneer thinkers in geomorphology. Davis put the foundation for concept of geomorphic cycle. Powell presented the concept of base level. • Gilbert introduced quantitative approach to study the relationship between stream load velocity and lateral erosion. • Waller Penck presented morphological system as against Davisian concept. https://www.directionias.com/