Necessity of Acknowledging Background Pollutants in Management and Assessment of Unique Basins

Abstract

The limitations of water quality management and assessment methods in China can be ascertained by comparison with other countries. However, it is unreasonable to use a uniform standard to evaluate water quality throughout China because one standard cannot fully account for the regional differences in background water quality. This study aimed to provide a basis for environmental water management decision-making. Areas seriously affected by background pollutants were identified by comparing several factors across 31 provinces in China. By coupling an improved export coefficient model (ECM) with a mechanistic model, a suitable pollutant yield coefficient was determined and its rationality was analysed. The export coefficient model was applied to estimate the pollutant (chemical oxygen demand and ammonia nitrogen) output of the basin in 2015. The spatial distribution characteristics of the pollutants were determined by simulating the pollutant outputs of 22 sub-basins and nine water function zones. For the year 2020, the simulation results of pollutant outputs far exceed the sewage discharge limit in water function zones and the pollutant concentration was much higher than the standard. Considering background pollutant outputs, more reasonable sewage discharge limit and water quality evaluation method are proposed.

Assessment of Water Quality for Aquaculture in Hau River, Mekong Delta, Vietnam Using Multivariate Statistical Analysis

“…The present study was carried out on the Hau River in An Giang and Can Tho Provinces, Vietnam, as illustrated in Figure 1. The Hau River is one of the two main branches of the Mekong River that flows to the Mekong Delta through the Cambodian border [22]. Among the two branches, the Hau River is located at the most southern side of the Mekong and runs through the Vietnamese territory in An Giang Province, An Phu District, Khanh An commune, as it flows into the South China sea [23].…”

“…Among the two branches, the Hau River is located at the most southern side of the Mekong and runs through the Vietnamese territory in An Giang Province, An Phu District, Khanh An commune, as it flows into the South China sea [23]. It splits into two sub-branches, namely: Tran De and Dinh An as it approaches the sea [22]. A total quantity of water amounting to approximately 20 m 3 per year flows into the sea from the Hau River [24], thus accounting for about 41% of the total Mekong water discharge, whereby 30% of the discharge flows through the Tran De channel.…”

“…In addition, multivariate analytical methods are also crucial in the evaluation and characterization of water quality to analyze spatiotemporal variations that have resulted from both natural and anthropogenic activities [20,21]. This is because water quality deterioration can only be solved through scientific and reasonable water quality assessment methods as a significant basis for ensuring proper water quality management and assessment [22]. The present study aims to address the issue by identifying the water parameters accountable for spatiotemporal variation of water quality in the Hau River using principal component analysis (PCA) and cluster analysis (CA).…”

Water Quality Assessment for Tigris River Through Salah Al-Din Province, Iraq Using Remote Sensing Techniques

“…Depending on the fact that the Alkalinity etiology is the presence of bicarbonate ions, carbonates, and hydroxyls, one can attribute the calculated value of PH= 8.3 to the existence of bicarbonate ionic and a little carbonate [18]. Alkalinity values ranged between (55-129.9) mg/l while the Standard value is 200 mg/l according to WHO.…”

Water Resources Management Models for Policy Assessment

“…They characterized stormwater quality variations among studied facilities and seasons, concluding with suggestions for future changes for decision makers. The work by Duan et al [23] focused on background pollutants and their influence on water quality management and assessment methods in China. The authors argue that it is unreasonable to use a uniform standard to evaluate water quality across the country.…”