Tuesday 28 September 2021 ,
Tuesday 28 September 2021 ,
Latest News
  • Bangladesh reports 1,212 fresh cases, 25 deaths from COVID-19
  • Dengue: 2 more die in Dhaka, 214 hospitalized in 24 hrs
  • SSC exams to begin on Nov 14, HSC on Dec 2
25 August, 2019 00:00 00 AM
Print

Dredging and the environment

THE HUGE NUMBER DREDGING IS A NECESSARY ACTIVITY THAT IS REQUIRED TO INCREASE THE DEPTH OF RIVERS AND REMOVE THE UNWANTED DEPOSITS FOR SAFE PASSAGE OF BOATS AND SHIPS
Dredging and the environment

The adverse affects of climate change are becoming clear to all. This unwelcome phenomenon is at present a serious cause for concern. It must be accepted that human activities are playing a role in the increase of greenhouse gas emissions that have accelerated global warming during the last century. Rivers of Bangladesh are also feeling the impact. An exclusive report published in The Independent   states that rivers now carry over two billion tonnes of sediment from the upstream during the monsoon each year, causing a rise in the country’s riverbeds and massive floods. Against this backdrop, the Bangladesh Inland Water Transport Authority (BIWTA) has taken up a 9-year-long mega dredging project to restore the country’s waterways through river management and reduce floods.

Dredging is a necessary activity that is required to increase the depth of rivers and remove the unwanted deposits for safe passage of boats and ships. However it also must be considered that by its very nature, the act of dredging will change the environment. Green activists in Bangladesh and around the world are concerned about the geomorphic effects of dredging rivers. The exact ramifications of river dredging upon the aquatic environment will depend on topology, sediment characteristics, the dredging technique employed, existing floodplain connectivity and antecedent environmental conditions.

Dredging activities potentially affect not only the site itself, but also surrounding areas, through a large number of impact factors, such as turbidity, sedimentation, resuspension and release of contaminants. Effects can be immediate or develop over a longer time frame and they may be temporary or permanent. Dredging will affect a river's composition, diversity and resiliency in a variety of ways. After a river is dredged, its banks will become prone to erosion. Eroded banks will stimulate further build-up of silt, exacerbating rather than improving problems with navigation. Moreover, disturbance of bank vegetation caused by erosion will remove cover and shade. This will increase light penetration and hence water temperature, which will cause fish to migrate. Besides, loss of soils will disturb the habitat of river bank fauna.  River dredging can have a number of impacts on local fish populations. Many fish species depend on structured habitats for refuge from the current. The loss of natural habitat can render new dredged habitats unsuitable for shallow-water fish. Before undertaking any extensive dredging programmes the environment must be taken into account.

Comments

More Editorial stories
It is encouraging to note that use of Information and Communication Technology (ICT) has been expanded significantly in all spheres of life in Rajshahi division. People are getting e-services related…

Copyright © All right reserved.

Editor : M. Shamsur Rahman

Published by the Editor on behalf of Independent Publications Limited at Media Printers, 446/H, Tejgaon I/A, Dhaka-1215.
Editorial, News & Commercial Offices : Beximco Media Complex, 149-150 Tejgaon I/A, Dhaka-1208, Bangladesh. GPO Box No. 934, Dhaka-1000.

Editor : M. Shamsur Rahman
Published by the Editor on behalf of Independent Publications Limited at Media Printers, 446/H, Tejgaon I/A, Dhaka-1215.
Editorial, News & Commercial Offices : Beximco Media Complex, 149-150 Tejgaon I/A, Dhaka-1208, Bangladesh. GPO Box No. 934, Dhaka-1000.

Disclaimer & Privacy Policy
....................................................
About Us
....................................................
Contact Us
....................................................
Advertisement
....................................................
Subscription

Powered by : Frog Hosting