External Stressors in the Sundarbans

A transboundary scale study

This project seeks to explore if external stressors impact the Sundarbans on a transboundary scale

It is one of the chapters from my PhD thesis on Transboundary Governanace of the Sundarbans

Upstream Barrage/ Dams

Upstream Barrages/Dams causes reduction in freshwater and sediment supply.Reduction in freshwater leads to change to salinity pattern and reduction in sediments causes disturbance to the natural sediment dynamics which eventually causes excessive erosion.

Industrial Water Pollution

Several industries are present upstream from the Sundarbans which release untreated substances directly into the water stream. Such sources of pollution can alter waster chemistry and affect mangrove growth.

Extreme Weather Events

The Sundarbans are prone to extreme cyclones, tidal surges and heavy rains which can cause long-term losses and damages. It also faces fluctuations in precipitation where access rainfall can also cause loss of land and damage to mangroves.


The growth of tourism industry in the Sundarbans indirectly pressurizes the system due to increased pollution, land clearing, and disturbance to species, however, if managed properly tourism can also lead to positive conservation outcomes.


Although embankments are constructed to halt saltwater intrusion in farmland and households but it obstructs water circulation, hinders mangrove growth, leads to deforestation, damages bottom sediments and often break within few years which causes further loss.

Maritime Trans- portation

Maritime transportation is becoming one of the leading causes of mangrove degradation and loss. Construction of ports, harbors, and jetties causes mangrove deforestation and constant movement of big ships causes water pollution, strong waves, and turbidity.

Sea Level Rise

Sea level rise due to climate change has the potential to cause loss of land and mangroves in the future if other anthropogenic pressures (especially reduced sediment supply) are not checked.

Land Cover Change

A leading cause of mangrove loss is for establishing aquaculture ponds and human settlements which continues to, directly and indirectly, disturbs the dynamics and functionality of the system for a long time.

The project focuses on understanding the scale at which external stresosrs are affecting the Sundarbans. External stressors are defined as any biological, chemical, physical or social force originating outside of the boundary of the system which has a negative impact on the system. The interaction between multiple external stressors can make the system vulnerable. Considering the distribution of local and global external stressors, the vulnerability/ impact within a system can vary where some areas within a system can be more vulnerable as compared to other areas.

The purpose of this survey is to gather general perception on the various external stressors affecting the Sundarbans.Your responses will help in assignig weights to each stressor for a comparative analysis of their impact on the Sundarbans. The data from this survey will be used to create a cumulative impact map of vulnerability of the Sundarbans. The result will be used to understand and plan effective management strategies for the conservation of the Sundarbans in India and Bangladesh.

    * Please read the brief description of each stressor before answering questions. You may find the description under the "Stressors" tab or by scrolling up.

    * The survey is voluntary. You are free to stop or leave the survey at anytime.

    * Once you leave or refresh the site, the survey progress will not be stored.

    * Please fill the survey to the best of your understanding, it is OK to answer in general terms.

    * There are 9 questions per stressor. Please answer all the questions before submitting.

    * You can use the comment box at the end of each streesor in Q9 to give additional inputs or qualitative information.

    * Question four for each stressor asks you to select a box on the map where you think most impacted has taken place. You can refer to Google Map link provided there for a finer scale map. Please search for landmark location where you know impact has taken place and then select respective box(s) on the map. It is OK if you are not very precise with location selection.

INSTRUCTIONS: Use the up and down arrow keys to go across the stressors, right and left arrow keys to go around the questions for the selected stressor. The boxes at the bottom can be used to navigate across the questions and the highlighted box will show you the question you are currently at. The boxes below stressor names will show your progress through the survey. If a box is unanswred it will not be filled with blue color. You may navigate to the unanswered questions before submitting the survey.


Upstream Barrage/Dams

Industrial Water Pollution

Extreme Weather Events



Maritime Transportation

Sea Level Rise






play_circle_outline Prev

Next play_circle_outline

Radhika Bhargava

(PhD Candidate)

Mangrove Lab

Department of Geography

National University of Singapore