Longitudinal Chemical Gradients and the Functional Responses of Nutrients, Organic Matter, and Other Parameters to the Land Use Pattern and Monsoon Intensity

River water quality degradation is one of the hottest environmental issues worldwide. Therefore, monitoring water quality longitudinally and temporally is crucial for effective water management and contamination control. The main aim of this study was to assess the longitudinal variations in water quality in the mainstream of the Han River, Korea, from 2015 to 2019. The trophic state classification (TSC), microbial pollution indicator (MPI), and river pollution index (RPI) were calculated to characterize river water quality and revealed more serious pollution toward the downstream zone (Dz) due to agricultural and urban-dominated areas. The biodegradability index (BI) indicated that non-biodegradable organic pollutants are increasing in the water body from the urban and animal wastewater treatment plants. Nutrients, organic matter contents, total suspended solids, ionic factors, and algal chlorophyll were higher in the Dz than in any other zones and were markedly influenced by the summer monsoon. Empirical analysis showed that nutrients and organic matter had positive linear functional relations with agricultural and urban coverage and negative linear relations with forest coverage. The pollutant-transport function suggested that suspended solids act as TP and TN carriers. Regression analysis indicated that TP (R2 = 0.47) has more positive functional relations with algal growth than TN (R2 = 0.22). Our findings suggest that a combination of empirical models and pollution indices might be utilized to assess river water quality and that the resulting information could aid policymakers in managing the Han River.

Pembuatan Filter Air Sungai dan Penyediaan Penampungan Air Bersih di Desa Penadaran

Penadaran Village is a village in Gubug District, Grobogan Regency, Central Java Province. The dry season makes residents in Penadaran Village experience problems with clean water sources. The purpose of community service is to make filters and provide clean water reservoirs for the residents of Penadaran Village. The implementation methods used are: (1) Conducting Tuntang River Water Quality Test, (2) Designing a scheme for clean water filters and reservoirs, (3) Making clean water filters and reservoirs. The location is in Kedungkakap Hamlet, Penadaran Village. The implementation time is August – October 2021. The results of the implementation of community service, obtained the results of the Tuntang River Water Quality Test, namely, Iron: 0.496 mg/L, COD: 301 mg/L, Chloride: 7.30 mg/L, manganese: 0.502 mg/ L, the river water filter scheme uses a system with 3 settling tanks and 2 mixed bed tubes. The shelter uses a 3300 ml Toren with a tower as high as 3 m from the ground. There are 17 families who have received clean water supply from the new source

GRQA: Global River Water Quality Archive

Large-scale hydrological studies are often limited by the lack of available observation data with a good spatiotemporal coverage. This has affected the reproducibility of previous studies and the potential improvement of existing hydrological models. In addition to the observation data themselves, insufficient or poor-quality metadata have also discouraged researchers from integrating the already-available datasets. Therefore, improving both the availability and quality of open water quality data would increase the potential to implement predictive modeling on a global scale. The Global River Water Quality Archive (GRQA) aims to contribute to improving water quality data coverage by aggregating and harmonizing five national, continental and global datasets: CESI (Canadian Environmental Sustainability Indicators program), GEMStat (Global Freshwater Quality Database), GLORICH (GLObal RIver CHemistry), Waterbase and WQP (Water Quality Portal). The GRQA compilation involved converting observation data from the five sources into a common format and harmonizing the corresponding metadata, flagging outliers, calculating time series characteristics and detecting duplicate observations from sources with a spatial overlap. The final dataset extends the spatial and temporal coverage of previously available water quality data and contains 42 parameters and over 17 million measurements around the globe covering the 1898–2020 time period. Metadata in the form of statistical tables, maps and figures are provided along with observation time series. The GRQA dataset, supplementary metadata and figures are available for download on the DataCite- and OpenAIRE-enabled Zenodo repository at https://doi.org/10.5281/zenodo.5097436 (Virro et al., 2021).

Pencemaran Air dan Penentuan Titik Self-Purification Sungai di Kabupaten Banjar

The self-purification capacity is an important indicator for a healthy river. Organic and inorganic pollutants from various pollutant sources, both point sources, and non-point sources, in most rivers in Banjar Regency, cause a decrease in river water quality. This study aims to identify the distribution of river water quality pollution in Banjar Regency as the upstream of the Martapura River and determine the point of self-purification. A sampling of river water using the purposive sampling technique, taking into account the criteria for pollutant sources and the distance of pollution. The results of the concentration values were analyzed using a trend analysis technique, which connected the value of the concentration of pollutant elements with the distance of pollution to identify the distribution of pollution, and to determine the distance of purification. The results showed that the self-purification ability (pH and DO) decreased in concentration at all observation points.

Anthropogenic Disturbances Have Contributed to Degradation of River Water Quality in Arid Areas

The earth has been reshaped for millennia. The accelerating pace of anthropogenic activities has generated enormous impacts on the water environment. As one of the main drivers of landscape change, anthropogenic disturbance has brought many negative effects on rivers. Studying the relationship between anthropogenic disturbances and river water quality is of significance for regional conservation and ecosystem management, while the relationship remains poorly understood in the current. In this study, we quantified anthropogenic disturbances by introducing the concept of the hemeroby index and evaluated rivers’ water quality in eight sub-watersheds on the Loess Plateau. The results indicated that 37.5% of the sub-watersheds were in Eutrophic status, and 62.5% were in Marginal water quality index. The river water quality was most poor in the southwestern region near the Yellow River with high-level anthropogenic disturbance. A correlation analysis between water quality indicators and hemeroby suggested that anthropogenic disturbance contributed to a significant water quality deterioration trend (p < 0.01). The river water quality was relatively sensitive to the changes of completely disturbed land-use covers, including urban and industrial land. Our findings provide theoretical guidance for regional water resources conservation and ecosystem management in arid areas.

Unfolding Water Quality Status During COVID-19 Lockdown for the Highly Polluted Santiago River in Jalisco, Mexico

The Santiago River is one of Mexico's most polluted waterways and evaluating its surface water quality during the COVID-19 outbreak is critical to assessing the changes and improvements, if any, from the nationwide lockdown (April-May 2020). Hence, the data for 12 water quality parameters from 13 sampling stations during April-May 2020 (lockdown) were compared with the levels for the same period of 2019 (pre-lockdown) and with the same interval of previous eleven-years (2009-2019). The values of BOD (14%), COD (29%), TSS (7%), f. coli (31%), t. coli (14%) and Pb (20%) declined, while pH, EC, turbidity, total nitrogen and As enhanced by 0.3-21% during the lockdown compared to the pre-lockdown period suggesting decrements of organic load in the river due to the temporary closure of industrial and commercial activities. An eleven-year comparison estimated the reduction of pH, TSS, COD, total nitrogen and Pb by 1-38%. The analysis of water quality index estimates showed short-term improvements of river water quality in the lockdown period, compared to pre-lockdown and eleven-year trend as well as indicated very poor quality of the river. The contamination sources identified by factor analysis were mainly related to untreated domestic sewage, industrial wastewaters and agriculture effluents influencing the river water quality. Overall, our findings demonstrated positive responses of COVID-19 imposed lockdown on water quality of the Santiago River during the study period, providing a foundation for the government policy makers to identify the sources of pollution, to better design environmental policies and plans for water quality improvements.