Water Quality In Basin Research Articles

Changing Land Use and Population Density Are Degrading Water Quality in the Lower Mekong Basin

Establishing reference conditions in rivers is important to understand environmental change and protect ecosystem integrity. Ranked third globally for fish biodiversity, the Mekong River has the world’s largest inland fishery providing livelihoods, food security, and protein to the local population. It is therefore of paramount importance to maintain the water quality and biotic integrity of this ecosystem. We analyzed land use impacts on water quality constituents (TSS, TN, TP, DO, NO3−, NH4+, PO43−) in the Lower Mekong Basin. We then used a best-model regression approach with anthropogenic land-use as independent variables and water quality parameters as the dependent variables, to define reference conditions in the absence of human activities (corresponding to the intercept value). From 2000–2017, the population and the percentage of crop, rice, and plantation land cover increased, while there was a decrease in upland forest and flooded forest. Agriculture, urbanization, and population density were associated with decreasing water quality health in the Lower Mekong Basin. In several sites, Thailand and Laos had higher TN, NO3−, and NH4+ concentrations compared to reference conditions, while Cambodia had higher TP values than reference conditions, showing water quality degradation. TSS was higher than reference conditions in the dry season in Cambodia, but was lower than reference values in the wet season in Thailand and Laos. This study shows how deforestation from agriculture conversion and increasing urbanization pressure causes water quality decline in the Lower Mekong Basin, and provides a first characterization of reference water quality conditions for the Lower Mekong River and its tributaries.

Assessment and distribution of water quality of Pandoh river basin (PRB), Himachal Pradesh, North India

As the surface water in northern India is the main water resource for regional economic and also supply for drinking and irrigation purposes. However, deficiency of water quality leads to serious water pollution in the Pandoh river basin (PRB). Therefore, the main objective of the present study is to evaluate the quality of surface water. With this objective, surface water samples were collected from the PRB of northern India, and analyzed for pH, EC, turbidity, alkalinity, total dissolved solids, and total hardness. Moreover, geographical information system (GIS) tools were used to prepare the geology, drainage pattern, and location maps of the study region. Surface water quality observed from the PRB has an alkaline nature with a moderately hard type. Further studies are encouraged to better understand the water quality in northern India.

Investigation of environmental and land use impacts in forested permafrost headwaters of the Selenga-Baikal river system, Mongolia - Effects on discharge, water quality and macroinvertebrate diversity

Headwater streams play a major role for provision of ecosystem services, e.g. drinking water. We investigated a high-altitude headwater catchment of the Kharaa River (including 41 1st-order rivers) to understand the impact of land cover (especially forest cover), environment and human usage on runoff, chemical water quality and macroinvertebrate fauna in a river basin under discontinuous permafrost conditions in an arid, sparsely populated region of Mongolia. To verify our hypotheses that different landuses and environmental impacts in permafrost headwaters influence water quality, we investigated 105 sampling sites, 37 of them at intermittent stream sections without water flow. Discharge was positively impacted by land cover types steppe, grassland and forest and negatively by shrubland, forest burnt by wild fires (indicating a reduction of permafrost) and slope. Water quality was affected by altitude, longitude and latitude, shrub growth and water temperature. Shannon diversity of macroinvertebrates was driven by water temperature, iron content of the water, flow velocity, and subbasin size (adjusted R2 = 0.54). Sample plots clustered in three groups that differed in water chemistry, macroinvertebrate diversity, species composition and bio-indicators. Our study confirms that steppes and grasslands have a higher contribution to runoff than forests, forest cover has a positive impact on water quality, and diversity of macroinvertebrates is higher in sites with less nutrients and pollutants. The excellent ecological status of the upper reaches of the Kharaa is severely threatened by forest fires and human-induced climate change and urgently needs to be conserved.

A transdisciplinary approach supports community-led water quality monitoring in river basins adjacent to the Great Barrier Reef, Australia

Water quality monitoring programs (WQMPs) are crucial for assessment of water quality in river basins where agricultural intensification and development raise concerns in freshwater and marine environments. WQMPs if supported by scientists and local communities, and if based on the knowledge needs of all stakeholders, can provide vital information supporting resource management actions.Our paper focuses on the transdisciplinary development and implementation of a community-led pilot WQMP for the Tully River basin, adjacent to the Great Barrier Reef (GBR). The community-led pilot WQMP was established to fill some knowledge gaps identified during development of the Tully Water Quality Improvement Plan (WQIP) and to provide opportunities for active stakeholder participation in the monitoring. Results indicated some water quality parameters (i.e. nitrates and total phosphorus) had higher than expected values and exceeded state water quality guidelines. Hence, the results provided an evidence base for freshwater quality objective development to conserve, protect and improve water quality conditions in this basin and GBR. Leadership of Indigenous people in the pilot WQMP recognizes their deep desire to improve water resources outcomes and to care for country and people.

Dynamic water system modeling: a systematic review

Abstract Improving water resource management at a global scale is critical at this time. The risks to which bodies of water are currently exposed, whether due to climate change or anthropogenic conditions, affect water availability and quality in basins around the world. Nevertheless, water management has been revealed as a complex problem. In this light, one of the most promising methodologies is building dynamic simulation models, which may include the largest possible number of variables, not just hydrological. In this way, we may gain a broader perspective on all the natural and social dimensions encompassed in basins and, thus, improve decision making for the benefit of the population. This systematic review seeks to report the most representative results from several authors who have developed dynamic models applied to the management of water resources. Herein, special emphasis is placed on water resource management applied to basin models, decision making, and public policies, as well as on the modeling tools used and on model validation.

Socio-Economic Analysis of Creating Coastal Reservoir in Welang Coastal Area, Pasuruan: Comparison with on-land Reservoir

Welang river is located in a residential area and national road access as well as a productive agricultural area which must be maintained. Floods that often hit the location disrupt economic activity and regional economic growth. The estuary and the capacity of the river sections, especially around the estuary are not able to accommodate and drain the flood discharge. The flood overflows caused inundation in Pasuruan, especially on national roads, agricultural lands, and industrial areas. To control the destructive power of the Welang river, it is necessary to plan an appropriate infrastructure for flood control in the Welang River especially when the high water discharge meets the high tide. This paper discusses the comparison between coastal and on-land reservoirs. In addition, based on economic analysis, the Benefit-Cost Ratio for on-land reservoirs is 1 and for coastal reservoirs is 1,54. Therefore, the coastal reservoir project is more economically feasible to carry out than an on-land reservoir with less social impact. This study also shows that with the use of the coastal reservoirs, the river runoff, water supply, and the water quality in Welang river basins can be improved.

Water Quality Degradation in the Lower Mekong Basin

The Mekong River is one of the world’s largest rivers, unparalleled in terms of its biodiversity and ecosystem services. As in other regions, sufficient water quality is required to support diverse organisms, habitats, and ecosystems, but in the Mekong region, water quality has not been well studied. Based on biological and physical-chemical data collected over the last two decades, we evaluated spatial-temporal water quality of the Lower Mekong Basin (LMB) using biotic and abiotic assessment metrics. We found that during the 2000s, water quality in the LMB was unpolluted, with “very good” metrics for tributary rivers and “good” status for mainstem rivers. However, during the last decade, water quality has been degraded in the LMB, particularly near Vientiane City; the Sekong, Sesan, and Srepok (3S) Rivers; the Tonle Sap Lake system; and the Mekong Delta. Water quality degradation likely corresponds to flow alteration, erosion, sediment trapping, and point and non-point wastewater, which have occurred from rapid hydropower development, deforestation, intensive agriculture, plastic pollution, and urbanization. Regular biomonitoring, physical-chemical water quality assessment, transparent data sharing, and basin-wide water quality standards or management are needed to sustain water quality to support biodiversity and ecosystem function in the LMB.

Modeling water quantity and quality for a typical agricultural plain basin of northern China by a coupled model

Water crisis across the globe has placed high pressure on social development due to the need to balance the water consumption between sustainable economy and functioning ecosystem. Integrated process-based modeling has been reported as an effective tool to better understand the complex mechanisms of water issues on a basin scale. Considering that it is still relatively difficult to simulate the water quantity-quality processes simultaneously, this study proposed an integrated modeling framework by coupling a hydrological model with a water quality model. Taking the Xiaoqing River Basin in the Shandong Province of northern China as an example, this study coupled a distributed hydrological model, SWAT, with a one-dimensional hydrodynamic-water quality model, HEC-RAS, to investigate its ability to simulate water quality and quality at the basin scale. The coupling of the two models adopted the “output-input” scheme, where the runoff modeling results from SWAT are input into HEC-RAS for hydrodynamic and water quality simulations of the river channel. The results show that the SWAT model can adequately reproduce runoff with accepted accuracy for the calibration and validation periods with acceptable R2 and Nash-Sutcliffe coefficients for the two hydrological stations. Further analysis also shows that the coupled model can simulate the concentration of ammonia nitrogen (NH4-N) and the chemical oxygen demand (COD) in the middle and upper stream of the river for both low and high flow periods. The coupling of the hydrological and hydraulic models in this study provides a good tool for identifying the spatial patterns of the water pollutants over the basin and, thus, helps simplify precision water management.

Agricultural impacts drive longitudinal variations of riverine water quality of the Aral Sea basin (Amu Darya and Syr Darya Rivers), Central Asia

River ecosystems are under increasing stress in the background of global change and ever-growing anthropogenic impacts in Central Asia. However, available water quality data in this region are insufficient for a reliable assessment of the current status, which come as no surprise that the limited knowledge of regulating processes for further prediction of solute variations hinders the development of sustainable management strategies. Here, we analyzed a dataset of various water quality variables from two sampling campaigns in 2019 in the catchments of two major rivers in Central Asia—the Amu Darya and Syr Darya Rivers. Our results suggested high spatial heterogeneity of salinity and major ion components along the longitudinal directions in both river catchments, pointing to an increasing influence of human activities toward downstream areas. We linked the modeling outputs from the global nutrient model (IMAGE-GNM) to riverine nutrients to elucidate the effect of different natural and anthropogenic sources in dictating the longitudinal variations of the riverine nutrient concentrations (N and P). Diffuse nutrient loadings dominated the export flux into the rivers, whereas leaching and surface runoff constituted the major fractions for N and P, respectively. Discharge of agricultural irrigation water into the rivers was the major cause of the increases in nutrients and salinity. Given that the conditions in Central Asia are highly susceptible to climate change, our findings call for more efforts to establish holistic management of water quality.

Anthropogenic influence on water quality and phytoplankton diversity of upper Ganga basin: A case study of Ganga River and its major tributaries

AbstractWater quality plays a vital and key role in estimating the diversity and abundance of phytoplankton in freshwater ecosystem. The water quality of freshwater body is rapidly deteriorating by various anthropogenic activities and diverse emancipations from the population growth, urbanization, and industrialization. The aim of present research work was to estimate the anthropogenic influence on water quality and phytoplankton diversity of upper Ganga basin. The water quality and plankton diversity of a Ganga River and its major tributaries was studied between September 2018 and September 2020 in eight sampling stations. Some physico‐chemical parameters like turbidity, dissolved oxygen, and biological oxygen demand showed a slight increase in sampling stations 7 and 8. Multi‐correlation was calculated between physico‐chemical parameters and phytoplankton density. Totally 31 genera of phytoplankton were recorded and represented by five groups, Bacillariophyceae (14 genera), Chlorophyceae (11 genera) Myxophyceae (4 genera), Euglenophyceae (1 genera), and Xanthophyceae (1 genera). Dissolved oxygen showed a direct influence on the distribution of plankton and also showed a positive correlation with phytoplankton diversity. Finally, it can be concluded that human activities including River bed mining, construction of Dam, and barrages had negatively impacted the water quality and phytoplankton diversity. Still, these kinds of activities to be checked regularly and can be controlled.

Predicting basin water quality using source-sink landscape distribution metrics in the Danjiangkou Reservoir of China

Land use and land cover changes due to human development are a concern for water-resource managers as they increase the spread of non-point source pollution to rivers, lakes, and reservoirs, impacting the quality of freshwater resources. Danjiangkou Reservoir is the largest inter-regional water transfer project in China and provides water services to cities along the middle route of the South-to-North Water Transfer Project and Beijing. Hence, watershed management decisions that may affect the water quality of the reservoir are particularly important. This study investigated the land use and land cover of a typical agricultural basin near the Danjiangkou Reservoir. The basin was divided into 13 sub-basins and the water quality was sampled six times during 2018 to determine the water quality index (WQI) for each sub-basin. The land use type and digital elevation model of each sub-basin were derived from remote-sensing data and then used to determine source-sink landscape distribution metrics; including the flow accumulation index (FAI), location-weighted landscape contrast index (LWLI), and landscape capacity distribution index (LCDI). Correlation and regression analysis were then used to compare these indices with the WQI. The WQI had a significant negative correlation with both the LWLI and LCDI, and a weak correlation with the FAI. Results indicated that the land use classification, proportion of source and sink landscape types, landscape flow path length, and landscape nutrient inputs were the main explanatory factors for river water quality in the basin. The biggest challenge in the research process is to obtain the parameters of landscape pattern index and its tedious calculation formula. The most successful part of the study is that it takes into account the flow path, roughness coefficient of land, nutrient input and other factors, more truly simulates the rainfall runoff process under natural conditions, and obtains better regression results between each evaluation index and water quality index. These findings show that remote-sensing data can be used in lieu of direct sampling to evaluate basin-water quality. Furthermore, these data can be used to predict the impact of future land use changes on water quality and facilitate more effective watershed management.

Impact of land-use/land-cover dynamics on water quality in the Upper Lilongwe River basin, Malawi

Impact of land-use/land-cover dynamics on water quality in the Upper Lilongwe River basin, Malawi

How far can hydrochemical characteristics of surface water meet drinking and irrigation criteria: a pragmatic study for the Euphrates river basin, Turkey

The primary intention of the current work was to appreciate the hydrochemistry characteristics and the water quality of the Euphrates river basin in Turkey. The water quality index technique (WQI) was adopted here for drinking criterion, while the United State salinity diagram and Wilcox’s diagram were constructed to assure the river expediency for irrigation standards. Factor analysis (FA) and cluster analysis (CA) were harnessed for identifying the paramount factors influencing the water quality and estimating the spatial variations amongst the sampling sites. It has been demonstrated that water–rock interactions have a pivotal influence on the river basin. It has been inferred from the Piper plot that water in the Euphrates basin is of Mg–HCO3 type. Alkaline earth metals and weak acids were prevalent rather than alkalis and strong acids. Besides that, silicate weathering is the dominant process within the river basin. Virtually, the majority of samples have met the drinking and irrigation standards. FA has revealed four factors that contributed to 71.453% of the total discrepancy in water quality while two disparate groups of similarities were uncovered between the sampling sites, reflecting palpable pollution levels within the river basin.

Imprints of COVID-19 lockdown on the surface water quality of Bagmati river basin, Nepal

COVID-19 pandemic has caused profound impacts on human life and the environment including freshwater ecosystems globally. Despite the various impacts, the pandemic has improved the quality of the environment and thereby creating an opportunity to restore the degraded ecosystems. This study presents the imprints of COVID-19 lockdown on the surface water quality and chemical characteristics of the urban-based Bagmati River Basin (BRB), Nepal. A total of 50 water samples were collected from 25 sites of BRB during the monsoon season, in 2019 and 2020. The water temperature, pH, electrical conductivity, total dissolved solids, dissolved oxygen (DO), and turbidity were measured in-situ, while the major ions, total hardness, biological oxygen demand (BOD), and chemical oxygen demand (COD) were analyzed in the laboratory. The results revealed neutral to mildly alkaline waters with relatively moderate mineralization and dissolved chemical constituents in the BRB. The average ionic abundance followed the order of Ca2+ > Na+ > Mg2+ > K+ > NH4+ for cations and HCO3˗> Cl˗ > SO42˗ > NO3˗ > PO43− for anions. Comparing to the pre-lockdown, the level of DO was increased by 1.5 times, whereas the BOD and COD were decreased by 1.5 and 1.9 times, respectively during the post-lockdown indicating the improvement of the quality water which was also supported by the results of multivariate statistical analyses. This study confirms that the remarkable recovery of degraded aquatic ecosystems is possible with limiting anthropic activities.

Operational Diagnosis of Arctic Waters with Instrumental Technology and Information Modeling

As a tool for assessing water quality in the Arctic Basin, a new technology is proposed based on the coupling of spectral observations of multi-channel optical sensors and mathematical model estimates for the qualitative and quantitative distribution of water pollutants. Adaptive spectrophotometer and spectroellipsometer structures are used to carry out the observations, the operation of which is described in detail. The mathematical model used relates to the spatial simulation of the dynamics of pollutants in the Arctic basin and was developed to assess the distribution of pollutants in Arctic aquariums, including Norway and the Bering Sea. In particular, a model is adopted for the study of heavy metals, oil hydrocarbons, phosphates, and other possible water pollutants. This model describes the interactions of pollutants with components of arctic ecosystems, including chlorophyll-a. It is shown that the proposed tool for combining spectrophotometric or spectroellipsometric observation equipment with the developed model provides to a very large extent the reliable distribution of heavy metals and oil hydrocarbons in all Arctic water.

PROTECTION OF RIPARIAN FORESTS AND WATER QUALITY IN A BASIN IN THE ATLANTIC FOREST BIOME

AbstractThe water quality of a drainage basin depends on the vegetation and soil of the region, land use and riparian forests, which act as a filter to protect the watercourse. For three years, we monitored several water quality parameters (turbidity, color, pH, conductivity, dissolved solids, alkalinity, and nitrate and chloride concentrations) in six adjacent microbasins to assess how riparian forests and land use affect water quality. The location is part of the Atlantic forest biome, with high-altitude humid subtropical climate and mixed ombrophilous forests. We designed a land use charter of the basin and a conflict map for fluvial permanent preservation areas. Land use included mainly natural forests, forestry, buildings, agriculture, and pastures. The multiple correlation analyses included: the water quality parameters, conflicts with permanent preservation areas, and land uses in river basins. In 51% of the basin, land uses complied with fluvial PPA legislation, but in 49% we found conflicts with other land use typologies and a lack of riparian forests. The quality of the water changed throughout the seasons and when fluvial PPAs conflicted with agriculture, buildings, and pastures. The different land uses in the basins did not influence the parameters of water quality and the same occurred with precipitation on water quality.

Impact of Climate Change on Worlds Economy and Hydrological System

The Mediterranean region appears to be particularly responsive to global and climate change. The global mean temperature has increased by 0.8°C compared with preindustrial levels while Europe has warmed more than the global average, especially in the Mediterranean, the north-east region, and mountain areas. Increasingly drier conditions are observed in the Mediterranean region both in the wet and in the dry season (~20%) with an increasingly irregular precipitation in both seasons (~ 40% in the dry season). The annual river flows have also decreased in the Mediterranean region, a difference projected to exacerbate due to climate and global change, which made the Mediterranean region most prone to an increase in drought hazard and water stress. Iberian Peninsula has been already affected by several major droughts, e.g. the recent one in 2005. These driving forces of global change impacts on water availability, water quality, and ecosystem services in Mediterranean river basins of the Iberian Peninsula, as well as their impacts on the human society and economy, makes it an important issue on the EU agenda. This thesis is an approach to quantify and analyze the water quantity, hydrological ecosystem services, and water supply in temperate regions under environmental changes. A hydrological model is developed for a low flow Mediterranean river (Francolí River) to assess the water allocation situation in the river basin using MIKE BASIN. Since the Mediterranean regions are hard hit by the changes in the global climatic patterns, the hydrological model focuses on the water distribution system & flow in the region.

A Review of 50 Years of Study of Hydrology, Wetland Dynamics, Aquatic Metabolism, Water Quality and Trophic Status, and Nutrient Biogeochemistry in the Barataria Basin, Mississippi Delta—System Functioning, Human Impacts and Restoration Approaches

Here we review an extensive series of studies of Barataria Basin, an economically and ecologically important coastal basin of the Mississippi Delta. Human activity has greatly altered the hydrology of the basin by decreasing riverine inflows from leveeing of the river and its distributaries, increasing runoff with high nutrient concentrations from agricultural fields, and channelization of wetlands of the basin interior that has altered flow paths to often bypass wetlands. This has resulted in degraded water quality in the upper basin and wetland loss in the lower basin. Trophic state analysis found the upper basin to be eutrophic and the lower basin to be mesotrophic. Gross aquatic primary production (GAPP) was highest in the upper basin, lowest in the mid basin, and intermediate in the lower basin. Forested wetlands in the upper basin have degraded over the past several decades due to increased periods of flooding, while there has been massive loss of emergent wetlands in the lower basin due to increasing water levels and pervasive alteration of hydrology. Restoration will entail reconnection of waterways with surrounding wetlands in the upper basin, and implementation of river sediment diversions, marsh creation using dredged sediments and barrier island restoration. Findings from this review are discussed in terms of the functioning of deltas globally.

Evaluating the impact of interbasin water transfer on water quality in the recipient river basin with SWAT

During the second half of the 20th century in South Korea, interbasin water transfers (IBWTs) have been used to supply the water demands of basins with insufficient water using water from reservoirs in neighboring basins with ample water. However, since 2000, frequent droughts have resulted in water resource imbalances in donor basins, and basin residents have begun to claim their water rights. Recipient basins have also experienced water shortages and water quality deterioration due to gradual urban growth, agricultural activities, and climate change impacts. In this study, the Mangyeong River basin (1602km2) was investigated. This basin has received 380 million m3/year of water since 2002 from the Yongdam multipurpose dam (YDD), which is located in another basin. For IBWT modeling, the Soil and Water Assessment Tool (SWAT) model and an inlet function were applied to model the recipient and donor water quality. Eight scenarios related to water transfer quantity and quality were applied with SWAT to analyze the effects of IBWT on the water quality in the recipient basin. The results showed that an increase in the IBWT amount helped to reduce the nutrient and suspended solids concentrations in the recipient basin when the donor's nutrient and suspended solids concentrations were lower than those in the recipient basin. The IBWT quantity scenarios had a greater impact on the water quality of the recipient basin than the IBWT quality scenarios. These results could provide basic information for use in deciding on the quantity and quality of IBWT between basins that are in conflict.

Characterizations Of Water Quality In West-Seti and Tamor River Basins, Nepal

This study presents the geochemical composition and water quality of waters in the West-Seti and Tamor River basins in Nepal Himalaya with the aim to reveal their hydrochemical characteristics and to evaluate the water quality. Water samples were collected from 18 sites of the rivers in the pre-monsoon season and analysed the physicochemical parameters to characterize their quality. The parameters- temperature, pH, conductivity, and total dissolved solids were measured in the field, while the major ions (Na+, Ca2+, Mg2+, Si4+, SO42−, NO3−, HCO3−, Cl−, and F−) were analyzed in the laboratory. Overall results of physicochemical parameters revealed that the ionic strength is much distinct; however, the waters are chemically pure in both the river basins with very less electrical conductivity (<250 µS/cm) and total dissolved solids (<120 mg/L). Bicarbonate (HCO3−) has a significant correlation with Ca2+ and Mg2+ suggesting carbonate rock weathering as the dominant geochemical process in both of the basins. The concentrations of Ca2+, Mg2+, and HCO3− in the water of the West-Seti is relatively higher than the waters in the Tamor River basin. Mostly, the geochemical facies of both the rivers are characterized by the Ca-Mg-HCO3- type (88.9%), with dominant carbonate dominated lithology. However, hydrochemical facies clearly suggested spatial discrimination between two basins with dominant geogenic signatures as Ca-SO4-Cl type water facies are also reported from the Tamor River basin. The results exhibited that the concentrations of measured parameters were relatively very low and within the WHO guideline values and currently under a safe level of the water quality for drinking and ecosystem health perspectives; however, further in-depth research is recommended in the periodic basis to assess traces of climate change imprints, and anthropogenic interferences for more consistent and reliable dataset. The findings of this study could be useful for the water quality management in the glacier-fed Himalayan River basins.