article · Water
An assessment of Phewa Lake in Nepal reveals distinct seasonal and spatial shifts in water quality across thirty sampling sites during pre-monsoon and post-monsoon periods. Water testing across twenty physicochemical parameters showed average dissolved oxygen levels rising from 7.46 milligrams per litre pre-monsoon to 8.62 milligrams per litre post-monsoon due to rainfall-driven aeration. Pre-monsoon conditions exhibited elevated pollution, with nitrate reaching 2.31 milligrams per litre, whilst phosphate peaked at 0.15 milligrams per litre post-monsoon near agricultural runoff areas. Carbonate weathering dictates the primary hydrochemistry, dominated by calcium, magnesium, and bicarbonate ions. Statistical evaluation identified sewage effluents and agricultural runoff as primary drivers of contamination, with the lake outlet functioning as a notable high-pollution zone carrying total dissolved solids between 108 and 135 milligrams per litre. Overall, monsoon rains drive dilution, whereas the pre-monsoon period concentrates pollutants.
Freshwater lakes provide critical drinking supplies, support biodiversity, and underpin local livelihoods, yet they face severe degradation from urban expansion and farming. Identifying specific sources of contamination and seasonal dilution patterns helps environmental authorities pinpoint where to intervene. Understanding these dynamics is essential for designing targeted nutrient management programmes and preventing toxic eutrophication in vulnerable freshwater ecosystems.
The abstract does not indicate a direct commercialisation pathway, presenting an early-stage monitoring assessment and management framework that may inform municipal catchment managers and environmental protection authorities rather than a proprietary market product.
AI-generated from the published abstract. Always read the original work before citing.
Lakes are vital freshwater ecosystems that sustain biodiversity, support livelihoods, and drive socio-economic growth globally. However, they face escalating threats from anthropogenic activities, including urbanization, agricultural runoff, and pollution, which are exacerbated by climate change. Phewa Lake in Nepal was selected for this study due to its increasing rates of nutrient enrichment, sedimentation, and pollution. This study evaluated seasonal and spatial water quality variations within the lake by analyzing water samples from 30 sites during the pre-monsoon and post-monsoon seasons. Twenty physicochemical parameters, including the potential of hydrogen (pH), dissolved oxygen (DO), electrical conductivity (EC), and major ions, e.g., calcium (Ca2+), magnesium (Mg2+), sodium (Na+), potassium (K+), bicarbonate (HCO3−), chloride (Cl−), sulfate (SO42−), nitrate (NO3−), phosphate (PO43−), and ammonium (NH4+), were measured. The average pH ranged from 8.06 (pre-monsoon) to 8.24 (post-monsoon), reflecting dilution from monsoon rains and increased carbonate runoff. Furthermore, the DO levels in Phewa Lake averaged 7.46 mg/L (pre-monsoon) and 8.62 mg/L (post-monsoon), with higher values observed post-monsoon due to rainfall-driven oxygenation. Nutrient concentrations were shown to be elevated, with the nitrate concentration reaching 2.31 mg/L during the pre-monsoon period, and the phosphate concentration peaking at 0.15 mg/L in the post-monsoon period, particularly near agricultural runoff zones. The dominant cations in the lake’s hydrochemistry were Ca2+ and Mg2+, while HCO3− was the primary anion, reflecting the influence of carbonate weathering. Cluster analysis identified the lake outlet as a high-pollution zone, with the total dissolved solids (TDS) reaching 108–135 mg/L. Additionally, Principal component analysis revealed agricultural runoff and sewage effluents as the main pollution sources. Seasonal dynamics highlighted monsoon-induced dilution and pre-monsoon pollution peaks. These findings underscore the need for targeted pollution control and eutrophication management. By aligning with the sustainable development goals (SDGs) relevant to clean water and climate action, this research provides a replicable framework for sustainable lake management that is applicable to freshwater ecosystems worldwide.
This page summarises published work. The authoritative version sits with the publisher.
DOI: 10.3390/w17020238
Is something wrong with this record? Report it or request removal.
Discussion
Have you built on this work, tried to replicate it, or seen it applied in practice? Share what you know. Verified researchers and MARATTO™ domain experts can open a discussion, and any member can reply. Contributions are reviewed before they appear.
No discussion yet. Open the first thread.
New to MARATTO™? Create a free account.
