Human intervention on river system: a control system—a case study in Ichamati River, India

With the advancement of human civilization, the river cascading system has been converted into a control system and man has a significant role in it. This paper has examined how the rivers, flowing across the highly populated Ganga–Brahmaputra Delta, are being obliterated due to the close contact of human civilization, as is an example of Ichamati River, an important distributary channel in the district of North 24 Parganas, India. The Ichamati River drains the east and south sides of the North 24 Parganas district and is covered by deep Quaternary sediments produced under tropical monsoon climate in India. The district is densely populated. GIS and a detail field investigation along with two case studies have been incorporated to extract the relationship between man and river, as a control system. This study significantly will draw the attention how the river has modified itself against imprudence human attitude towards environment without any proper river management. This paper has examined the human interventions over river, as a control system, and has discussed about the associated changing characters of river behaviour as the response, e.g. (1) longitudinal profile has been changed temporally due to human impact; (2) the characters of cross profiles have been changed due to the impact of bridge and other human influences; (3) the tidal discharge of the river has been changed downstream upward due to intake of water for different purposes. The primary objective of this article is to examine the role of man as an important controlling element of a river system.