Bridging the gap or broadening the problem?

Harinarayan Tiwari (), Subash Pd. Rai and Kumari Shivangi
Additional contact information
Harinarayan Tiwari: IIT Roorkee
Subash Pd. Rai: IIT Roorkee
Kumari Shivangi: Indira Gandhi National Open University

Natural Hazards: Journal of the International Society for the Prevention and Mitigation of Natural Hazards, 2016, vol. 84, issue 1, No 20, 366 pages

Abstract: Abstract A bridge is a structure built to span physical obstacles such as a body of water, valley or road for the purpose of providing passage over the obstacle. Bridges over rivers cause an alteration of flow and modify the flow characteristics because of the flow obstruction. Remote sensing and GIS techniques have been used to study the alterations in river meandering characteristics. The objective of this study is to analyse the changes in river characteristics downstream of a bridge using satellite images for the lower Ganges River at two bridge sites in Bhagalpur and Munger in Bihar, India. ARC-GIS is used to calculate the normalised difference water index (NDWI), which has the capability to represent water bodies adequately from space. Based on NDWI maps, the river channel length and downvalley length were measured for different spatio-temporal conditions. The above parameters (channel length and downvalley length) were used to estimate the Sinuosity Index under 14 spatio-temporal situations. The Sinuosity Index (i.e. an indicator of local river fluvial characteristics) varies significantly because of the effect of bridges and their associated structures. There was an increase in the Sinuosity Index of 30 % magnitude in an 8-year time period (2006–2014) after the bridge construction phase at both locations. The pre-construction phase of the bridges indicates minor changes in the Sinuosity Index during the 9-year period from 1987 to 1996. The NDWI analysis also reveals that the river characteristics changed considerably in the pre- and post-bridge scenarios while the change was less significant for pre- and post-flood events (May 2014 to October 2014).

Keywords: Ganges; India; Meandering; Sinuosity Index; Normalised Difference Water Index (search for similar items in EconPapers)
Date: 2016
References: View complete reference list from CitEc
Citations:

Downloads: (external link)
http://link.springer.com/10.1007/s11069-016-2422-x Abstract (text/html)
Access to the full text of the articles in this series is restricted.

Related works:
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: https://EconPapers.repec.org/RePEc:spr:nathaz:v:84:y:2016:i:1:d:10.1007_s11069-016-2422-x

Ordering information: This journal article can be ordered from
http://www.springer.com/economics/journal/11069

DOI: 10.1007/s11069-016-2422-x

Access Statistics for this article

Natural Hazards: Journal of the International Society for the Prevention and Mitigation of Natural Hazards is currently edited by Thomas Glade, Tad S. Murty and Vladimír Schenk

More articles in Natural Hazards: Journal of the International Society for the Prevention and Mitigation of Natural Hazards from Springer, International Society for the Prevention and Mitigation of Natural Hazards
Bibliographic data for series maintained by Sonal Shukla () and Springer Nature Abstracting and Indexing ().