Abstract

The aim of this study was to investigate the spatio-seasonal variations in water quality and suitability of the Shitalakhya river, an economically important and ecologically critical urban river in Bangladesh, along with associated influencing factors and possible sources of water pollution. Therefore, surface water samples were collected monthly from five sampling sites, and fourteen water quality parameters were evaluated. The results showed that some studied water quality parameters, e.g., temperature, TDS, TA, TH, NO₂^–, and NO₃^–, exceeded the maximum allowable limit, whereas statistically significant (p < .05) variations were observed among pre-monsoon (February–May), monsoon (June–September), and post-monsoon (October–January) seasons. The values of water quality index (WQI) exhibited that the water quality was found to be very poor to unsuitable for drinking, fisheries, or aquatic environment. The principal component analysis (PCA) extracted two PCs explaining 91.092% of the total variance, which suggested that the variations in water quality are attributed mainly to point and nonpoint sources of contamination including municipal and industrial wastewater discharge, and agricultural runoff of inorganic fertilizers. The cluster analysis (CA) also showed relative spatial and seasonal variations in river water quality, indicating the influence of hydrological changes and pollution sources. The study revealed that the water of the Shitalakhya river is highly polluted and potentially hazardous for human uses, and thus more attention should be given to safeguard such an important urban river.

摘要

这项研究的目的是调查Shitalakhya河（孟加拉国的经济上重要且对生态至关重要的城市河流）的水质和适用性的时空变化，以及相关的影响因素和可能的水污染源。因此，每月从五个采样点采集地表水样品，并评估了十四个水质参数。结果表明，一些研究的水质量参数，例如，温度，TDS，TA，TH，NO ₂ ^-和NO ₃ ^- ，超过了最大允许极限，而统计学显著（P <。05）在季风前（2月至5月），季风（6月至9月）和季风后（10月至1月）季节之间观察到变化。水质指数（WQI）的值表明，水质很差，不适合饮用，渔业或水生环境。主成分分析（PCA）提取了两台PC，解释了总方差的91.092％，这表明水质的变化主要归因于点和非点污染源，包括市政和工业废水排放以及无机肥料的农业径流。聚类分析（CA）还显示了河流水质的相对空间和季节变化，表明了水文变化和污染源的影响。