J. Environ. Res. Develop. Journal of Environmental Research And Development Vol. 8 No. 04, April-June 2014 997 STUDY FOR RESTORATION USING FIELD SURVEY AND GEOINFORMATICS OF THE KOLONG RIVER, ASSAM, INDIA Bora Minakshi* and Goswami Dulal C. Department of Environmental Science, Gauhati University, Guwahati (INDIA) Received December 25, 2013 Accepted May 5, 2014 ABSTRACT River engineering and the subsequent loss and fragmentation of Riparian habitats during recent centuries have had serious impacts on aquatic ecosystem. The Kolong River of Nagaon, Assam, India has also faced serious penalty of one of such radical engineering approach where the mouth of the river in Jakhalabandha was permanently closed during the year 1964 by constructing an earthen embankment across it, viz. the Hatimura dyke, with the chief objective of protecting Nagaon town against flood. The act of blocking has shattered the natural flow regime of the entire river leaving it in a moribund state. Here we briefly summarize the existing scenario of the study area with an emphasis on a possible river restoration technique. Seven well distributed sampling stations were selected for the study purpose. Water quality and hydrological parameters were determined using standard procedures. Base map, drainage map and land- use/land-cover map of the study area were prepared (Database: Survey of India Topological sheets, LANDSAT satellite imagery and IRS LISS-III satellite imagery) for acquiring a broad apparition about the geo-environmental setting of the study area. Results of the present study reveal the fact that a restoration paradigm is essential for management of the river’s health and ecosystem. A framework of the restoration program is discussed. Key Words : River engineering, Aquatic ecosystem, Kolong River, Earthen embankment, Flow regime, River restoration, LANDSAT INTRODUCTION Although river infrastructure, such as flood control barriers (e.g. levees, dykes, weirs and tide gates) dams and road crossings (e.g., culverts) supports an array of socioeconomic goods and services (e.g. flood control, water supply, transportation and renewable hydro- power) but they are also known for having widespread negative impacts on the ecology and hydrology of the concerned river. 1 As a consequence of this, abolition of artificial in- stream structures is increasingly seen as a viable option for sustainable watershed management. 2-7 The Kolong river of Nagaon district in Assam, which once used to be a prize possession for the people of the state in general and the people of Nagaon in particular, is presently gasping on its death-bed because of the ruthless and untenable act perpetrated on it in the name of engineering solution to the increasing flood hazard attributed to it in the aftermath of the great Assam earthquake of 1950. During the years preceding 1964, primarily as a consequence of the great Assam earthquake of 1950, this region experienced recurrence of large floods due mainly to raised bed level of the Brahmaputra through massive sedimentation vis-à-vis the level of Kolong, leading thereby to its higher flood levels inundating adjoining areas like Nagaon. Mainly as a response to the increasing flood hazard faced by the district administrative headquarter i.e. the Nagaon town, an adhoc flood control measure was undertaken by constructing an earthen embankment, known as Hatimura dyke, across the river’s take-off point near Hatimura in the year 1964. This drastic human intervention had resulted in converting the once free flowing river into a string of alternating dry stretches and stagnant *Author for correspondence © JERAD All rights reserved