Water Quality Index (WQI) for Evaluation of the Surface Water Quality of Bangladesh and Prediction of WQI from Limited Parameters

Abstract

Healthy aquatic environment is crucial for preserving aquatic lives in surface waters. Increasing industrial or agricultural discharge or run-off can pollute water leading to unhealthy aquatic environment causing distress in fishes and other aquatic lives. In places with lack of infrastructure and regulatory enforcement, pollution can be particularly challenging to handle. Assignment of an indexing system can be helpful for analyzing pollution pattern in the polluted rivers which can be helpful for remediation purposes and prevention of future pollution. Bangladesh currently does not have any indexing system in place. Assignment of indices in the rivers of Bangladesh can be helpful for remediation of the rivers on a preferential basis as remediation of all the rivers at once will pose challenges with funding and infrastructural allocation. Parameters monitored in the water monitoring stations of ten rivers were extracted from the reports published by the Department of Environment (DOE) of Bangladesh. A water quality index (WQI) was assigned on the rivers across seven years of time period to identify the most polluted rivers. The degree of pollution in the river was in the order of Mayuri > Buriganga > Korotoa > Turag > Shitalakhya > Surma > Halda > Dhaleshwari > Mathavanga > Brahmaputra based on the WQI analysis. Among the ten rivers, only Mathavanga and Brahmaputra were in good condition. The most polluted rivers were located in areas with manufacturing, textile etc. industries. Hence, monitoring of industrial discharge intro the rivers and regulatory enforcement is crucial for the prevention of pollution in rivers. In addition to regulatory enforcement, adoption of remediation plans and implementation of them is also essential for remediation of the polluted rivers.