Integrated Approach to Quantify the Impact of Land Use and Land Cover Changes on Water Quality of Surma River, Sylhet, Bangladesh

Zia Ahmed,Abdul Kadir,Zhixiao Xie,Pankaj Kumar,Md Misbah Uddin

doi:10.3390/w14010017

Abstract

This study aims to assess the impacts of land use and land cover (LULC) changes on the water quality of the Surma river in Bangladesh. For this, seasonal water quality changes were assessed in comparison to the LULC changes recorded from 2010 to 2019. Obtained results from this study indicated that pH, electrical conductivity (EC), and total dissolved solids (TDS) concentrations were higher during the dry season, while dissolved oxygen (DO), 5-day biological oxygen demand (BOD5), temperature, total suspended solids (TSS), and total solids (TS) concentrations also changed with the season. The analysis of LULC changes within 1000-m buffer zones around the sampling stations revealed that agricultural and vegetation classes decreased; while built-up, waterbody and barren lands increased. Correlation analyses showed that BOD5, temperature, EC, TDS, and TSS had a significant relationship (5% level) with LULC types. The regression result indicated that BOD5 was sensitive to changing waterbody (predictors, R2 = 0.645), temperature was sensitive to changing waterbodies and agricultural land (R2 = 0.889); and EC was sensitive to built-up, vegetation, and barren land (R2 = 0.833). Waterbody, built-up, and agricultural LULC were predictors for TDS (R2 = 0.993); and waterbody, built-up, and barren LULC were predictors for TSS (R2 = 0.922). Built-up areas and waterbodies appeared to have the strongest effect on different water quality parameters. Scientific finding from this study will be vital for decision makers in developing more robust land use management plan at the local level.

Highlights

Water is a vital resource for the maintenance of life, ecological functioning, biological diversity, and social well-being
The highest dissolved oxygen (DO) was found at Kazir Bazar, while the lowest was found at Keane Bridge in dry season
The result of the present investigation indicates that land use and land cover (LULC) changes and seasonal variations have a significant impact on water quality parameters

Summary

Introduction

Water is a vital resource for the maintenance of life, ecological functioning, biological diversity, and social well-being. Despite its importance for life, in recent decades, excessive human land use has severely harmed the quality and quantities of available water resources [1]. It is well known that rivers function as integrators of land-water connections, receiving pollutants from the surrounding landscapes [2], and river water quality could be negatively impacted. Urbanization, and industrialization, the surrounding landscape of the Surma river has been changing, and the riverside has experienced tremendous development in terms of commercial, human settlement, and industrial development. The population and urban sprawl have adverse effects on the quality of the Surma river water; the increased urban area is responsible for generating large amounts of nonpoint source pollution through runoff and degraded the river water quality

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Discussion

Conclusion