Himalayan movement, which brought into existence the successive mountain ranges- the Great Himalayas, Lower Himalayan Range, and the Sivalik ranges- into their present shape and altitude. It is these movements and associated thrusts that caused the formation of the Indo-Gangetic depression which is the playground of the Gangetic streams. Again, it was these movements which caused block uplifts along the northern edge of the Central Indian Foreland (Dunn, 1942) sharpening the gradient of the southern tributaries of the Ganga and creating waterfalls along with their courses and gorges as they descend the northern edge of the Central Indian Foreland" (Ahmad, 1971). He, therefore, traced the evolution of the Himalayan drainage commensurate with the geological and tectonic history of the region relating to the upheavals and movements during the Oligocene, Miocene, and Pleistocene period. For this reason, his theory has become the more accepted theory of the Himalayan drainage system. First Research Journal of Geography in Bihar According to the National Association of Geographers, he published "more than 64 articles in reputed international and national journals. Under his editorship, the Geographical Outlook, the first research journal of Geography in Bihar, was started in 1956. He had the honour of being the first geographer of the country whose papers were published in Annals of the American Association of Geographers, and Geographical Review. This was indeed a great achievement." Indian Coastal Geomorphology Ahmad’s book Coastal Geomorphology of India, published in 1972, was the first book on the subject. "In 22 concise chapters…Ahmad virtually describes every feature along a vast coastline. For this, students of both Geomorphology and India will be most grateful". This pioneering work was created, in the absence of any previous literature on the subject, from large-scale maps. The author was assisted in this work by coastal geomorphologist E.C.E. Bird and A.T.A. Learmonth. Although this work has also been criticized by Schwartz for not being rigorous, geologically, the fact remains that all work on Indian coastal geomorphology is subsequent to and follows this original and fundamental work. This work him brought international recognition. Ahmad also served as the Asian Contributor for Encyclopedia Britannica. Awards Ahmad posthumously received the Bhoogol Ratna Award of 2016 from by the National Association of Geographers, India (NAGI), in the 38th Indian Geography Congress, held at the University of Mysore, Mysuru in recognition of his services to the field. References 1923 births Indian geographers People from Bihar