Hydrochemistry, water quality and land use signatures in an ephemeral tidal river: implications in water management in the southwestern coastal region of Bangladesh

Abstract

Despite its complexity and importance in managing water resources in populous deltas, especially in tidal areas, literatures on tidal rivers and their land use linkage in connection to water quality and pollution are rare. Such information is of prior need for Integrated Water Resource Management in water scarce and climate change vulnerable regions, such as the southwestern coast of Bangladesh. Using water quality indices and multivariate analysis, we present here the land use signatures of a dying tidal river due to anthropogenic perturbation. Correlation matrix, hierarchical cluster analysis, factor analysis, and bio-geo-chemical fingerprints were used to quantify the hydro-chemical and anthropogenic processes and identify factors influencing the ionic concentrations. The results show remarkable spatial and temporal variations (p < 0.05) in water quality parameters. The lowest solute concentrations are observed at the mid reach of the stream where the agricultural and urban wastewater mix. Agricultural sites show higher concentration of DO, Na + and K + reflecting the effects of tidal spill-over and shrimp wastewater effluents nearby. Higher level of Salinity, EC, Cl − , HCO 3 − , NO 3 − , PO 4 3− and TSS characterize the urban sites indicating a signature of land use dominated by direct discharge of household organic waste into the waters. The spatial variation in overall water quality suggests a periodic enhancement of quality especially for irrigation and non-drinking purposes during monsoon and post-monsoon, indicating significant influence of amount of rainfall in the basin. We recommend that, given the recent trend of increasing precipitation and ground water table decrease, such dying tidal river basins may serve as excellent surface water reservoir to supplement quality water supply to the region.

Assessing the impact of land use and land cover dynamics on water quality of Dal Lake, NW Himalaya, India

“…Various studies such as National Research Council and Mono Basin Ecosystem Study Committee (1987), Council and Bennett (1993), Habersack and Nachtnebel (1995), Tenzer et al (1997), Hernandez and Ernest (1999), Schoonover et al (2005), Salvia-Castellví et al (2005, Salomons and Stigliani eds (2012), Mallick (2017), Thakur et al (2018), Denizman (2018), Jasrotia et al (2018), and Roy et al (2018) have shown that sediment-water interactions and the human activities such as agrarian and forestry practices, as well as the release of domestic wastewaters into the water bodies, are statistically related as have been analyzed in the present study.…”

Hydroclimatic Information Needs of Smallholder Farmers in the Lower Bengal Delta, Bangladesh

“…The region represents a low-lying coastal morphology that experiences frequent hydroclimatic hazards such as cyclones and storm surges, salinity invasions, and waterlogging [10]. The Rupsa-Bhairab-Pasur in the east and the Mayur river in the western boundary of the city play a key role in the agriculture-aquaculture farming systems of the area under investigation [48].…”

Influences on tidal channel and aquaculture shrimp pond water chemical composition in Southwest Bangladesh

“…Bangladesh experiences a strong monsoonal climate, where biseasonal precipitation causes approximately 80% of yearly rainfall to occur between the months of June to September (e.g., [ 11 , 18 , 51 ]). This large seasonal difference in precipitation can lead to vast changes in surface water chemistry during different seasons, particularly in coastal regions (e.g., [ 2 , 59 , 63 ]).…”

“…Although there has been much research in Bangladesh on groundwater and contaminants such as arsenic (As) (e.g., [ 4 , 7 , 17 , 38 , 47 , 48 ]), less emphasis has been placed on surface water chemistry, especially in Southwest Bangladesh. Multiple studies in Bangladesh have geochemically examined tidally dominated rivers (hereafter called tidal channels) and adjacent waterways in both temporal and spatial ways (e.g., [ 2 , 3 , 24 , 33 , 59 , 63 ]). Studies have also looked at trace element concentrations in aquaculture ponds near the coastal region of Bangladesh [ 23 , 32 , 62 ] or in coastal Bangladesh rivers [ 36 , 52 ] and nonspecified lakes/ponds [ 1 ].…”