Development of Drainage Systems and The Dynamic Cycle

IN recent papers Waldo S. Glock' has advanced the suggestion that physiography, or physical geography, should be regarded as dual in nature, having a static or passive phase called geomorphology and a or active phase which he would name geodynamics. I have elsewhere2 discussed the question as to whether geomorphology, which treats the active evolution of ever-changing land surfaces in terms of structure, process, and stage, can properly be regarded as static or passive. In the pages that follow it is desired to focus attention on another aspect of Glock's thought-provoking suggestion. He states that physiography may be approached from a purely viewpoint and proposes a dynamic cycle distinct from the geographic or geomorphic cycle. As concrete illustrations of the point of view he gives us a shorter and a longer discussion of the development of drainage systems in which successive phases of extension and integration of stream lines are illustrated by reproductions from selected topographic maps. The point of view is consistently adhered to in these illustrations, which show only streams of water and some of the associated marshes but no valleys. This gives the reader an opportunity to judge how effective may be the more restricted method of treatment

Biology · Drainage · Ecology · Hydrology and Sediment Transport Processes · Hydrology and Watershed Management Studies · Soil erosion and sediment transport