Similar Water Quality Research Articles

Use of bacteria community analysis to distinguish groundwater recharge sources to shallow wells.

In this study, bacteria community analysis was performed to supplement a preexisting evaluation of nitrate contamination in drinking water wells at a coastal site in Old Lyme, CT. Given well usage and coastal hydrogeologic conditions, the source(s) of nitrate contamination in domestic wells could not be discerned between local septic systems or a nearby farm where organic fertilizers were used. Groundwater bacteria communities are known to be sensitive to a variety of environmental conditions. As such, they are potentially useful in distinguishing groundwater recharge sources. Groundwater samples collected from wells were analyzed using polymerase chain reactions (PCR) and 16S rRNA sequencing to determine the bacteria distributions in each well. The biostatistical analysis of the data using Bray-Curtis nonmetric multidimensional scaling and permutational multivariate analysis of variance revealed three distinct bacteria community distributions that coincided with three different areas on the site. Additionally, principal component analysis (PCA) of the water quality data revealed that wells with similar bacteria shared similar water quality, all of which was indicative of local recharge. These findings suggested that the domestic well nitrate contamination was derived from local septic systems rather than the farm. Septic indicator analysis using ultra-performance liquid chromatography-tandem mass spectrometry determined the presence of caffeine in domestic wells, which was consistent with the conclusions from the bacteria analysis, PCA, and the known hydrogeologic conditions. The low cost, ease of sample collection, and growing availability of bioinformatics laboratory services and software are conducive to the application of microbial community analysis as a supplemental tool for groundwater investigations.

First Experiences with the Landsat-8 Aquatic Reflectance Product: Evaluation of the Regional and Ocean Color Algorithms in a Coastal Environment

Since the launch of the Landsat-8 (L8) Operational Land Imager (OLI) on 11 February 2013, there has been a continuous effort to produce reliable ocean color products by taking the advantages of its medium spatial resolution (30 m) and higher Signal to Noise Ratio (SNR). A Provisional Aquatic Reflectance product for the L8 OLI (L8PAR) has been recently released to the public to explore its potential for ocean color applications. This study used a six-year data record of L8 for development of a regionally tuned algorithm (RTA20) for estimating Chlorophyll-a (Chl-a) concentrations around the complex coastal environment of Hong Kong, and is the first to report the usability of the L8PAR product for coastal areas. Furthermore, this study validated three previously developed algorithms, namely RTA16, RTA17 and RTA19, and two ocean color algorithms (OC2 and OC3) modified for L8 OLI by NASA’s Ocean Color group. Results indicate that the newly released L8PAR product has a high potential for estimating the coastal water Chl-a concentrations with higher detail and higher accuracy than previously. The RTA20 algorithm developed in this study outperformed the previous algorithms (RTA16, RTA17, RTA19, OC2 and OC3), e.g., with lower values for Root Mean Square Error (RMSE; 0.92 mg/m3), bias (−0.26 mg/m3) and mean ratio (1.29). Although inferior to the RTA20, the OC2 algorithm also performed well in terms of Pearson’s correlation coefficient (r; 0.84), slope (6.87) and intercept (−8.44) while for RTA20 the values for r, slope and intercept were 0.96, 0.77 and 0.27, respectively. This preliminary evaluation reveals that the OC2 algorithm can be used as an operational algorithm for L8 Chl-a product generation for global coastal areas while RTA20 can be used as a regional algorithm for the routine monitoring of Chl-a concentrations around the coastal areas of Hong Kong or for coastal areas with similar water quality elsewhere in the world.

Evaluation of commercial and experimental grower diets for use in intensive burbot (Lota lota maculosa) culture

Burbot (Lota lota maculosa) are the only true freshwater gadiforms (cod-like fish) and are a promising new species for cold water aquaculture. This “freshwater cod” produces a delicate white flesh fillet, the liver and roe are considered delicacies, and the skin can be manufactured into leather. Furthermore, burbot grow-out requires similar water quality parameters as trout production, and burbot have been found to be relatively refractory to most primary salmonid pathogens. Burbot could be reared at existing trout production facilities and represent a means of diversifying production in already established cold water aquaculture operations. For commercial burbot culture to succeed, optimal diet selection for grow-out must be determined. To address this, two feeding trials were conducted to evaluate the effect of different dietary formulations on the growth of juvenile and subadult burbot. Four dietary treatments at fixed rations were evaluated, Europa (commercial), Oncor (commercial), a formulated marine-like reference diet (Burbot 1; B1), and a formulated trout-like reference diet (Burbot 2; B2). Juvenile growth results indicated a difference in relative growth (RG; P < .001) and biomass gain (BG; P < .001) among the marine blend dietary treatments, with the fish fed B1 and Europa showing better growth than the Oncor and B2 diets in these cases. This is indicative of a preference for marine-type diets during the juvenile life stage of burbot. Growth results also indicate a difference in protein efficiency ratio (PER; P = .008) among the diets, with the fish fed Europa exhibiting the lowest protein utilization rate. Subadult growth results indicate no differences in RG (P = .771), SGR (P = .804), BG (P = .727) for fish fed any of the diets. Thus, it appears that the subadult burbot grow and perform equally well on trout-like formulations at this life stage. While additional studies are needed, results from this work are important and indicate general dietary preference of burbot at juvenile and grow-out stages. Such information can be used to guide feed related decisions for current or future producers interested in commercial burbot production.

Analysis and evaluation of the spatial and temporal variabilities of river water quality parameters

This study aimed to analyze the status and evaluate the spatiotemporal variabilities of water quality in the Awash River, Ethiopia. The study also aims to identify the origin and geochemical composition of the river water. Temporal variabilities of similar water quality parameters in the Lake Beseka, a dramatically rising lake (0.2 m/year) in the Awash River basin, which is being channeled into the Awash River system in order to control the lake level rise, were also considered in this study. To do this, laboratory measurements and a 10-year consecutive record of physicochemical parameters, major ions, nutrients and minor ions of the Awash River and Lake Beseka waters, graphical methods and factor analysis approaches were used. The origin of the Awash River was found to be shallow-medium depth aquifer with a geochemical composition of Ca(HCO3)2 and NaHCO3, while the origin of Lake Beseka was found to be deep, ancient groundwater with a geochemical composition of NaCl and NaHCO3. However, mixing the lake water with Awash River in the downstream sites shifted the geochemical composition of the river water to a mixture of Ca(HCO3)2, NaHCO3 and NaCl water types. The results also showed that the river water quality varies spatially and temporally, controlled by three major factors: the combined effects of anthropogenic activities and mineral dissolutions (Factor-1), anthropogenic activities and ion exchange (Factor-2) and ion exchange (Factor-3). While Factor-1 was the main controlling factor of the river water quality, and Factor-3 was the least, all three factors equally controlled the temporal variabilities of water quality in Lake Beseka. The observed temporal and spatial variabilities of the river water quality suggest that frequent water quality evaluations are important in designing appropriate water management strategies in river systems near intensive agricultural, industrial, and urban development areas.

Assessment of Aquatic Macroinvertebrate Sampling Methods for Nonregulatory Water Quality Programs

Many land management water quality programs must assess water quality using aquatic macroinvertebrates for nonregulatory purposes but conduct these assessments using regulatory protocols. The costs of providing data using regulatory protocols can be financially burdensome for these programs. Macroinvertebrate water quality monitoring in Great Smoky Mountians National Park in the United States is assessed using six sampling methods (kicknet, Dnet, rockwash, sand, leafpack, and visual samples). Data for this study were collected from nine wadeable streams flowing through high‐gradient mountainous forests. Ephemeroptera, Plecoptera, and Trichoptera (EPT) taxa were identified to the lowest taxonomic unit as was practical. Comparisons were made among different sampling methods to determine if nonregulatory programs can obtain similar data with fewer collection methods. Richness, abundance, Shannon diversity, evenness, and dominance were compared among each of the sampling methods. Effort ratio (abundance/richness) was also compared. Methods producing high‐diversity samples were then combined and compared with the current six‐method protocol. All comparisons were made using an ANOVA and general linear model (P &lt; 0.05). Using combinations of kicknet–visual or rock wash–Dnet–visual samples resulted in similar richness, Shannon diversity, evenness, and dominance compared with all methods, while having lower abundance and effort ratios. Reducing sampling methods will reduce time invested in field sampling, sorting, and identifications, which will reduce program costs for nonregulatory management programs.Core Ideas Aquatic macroinvertebrate nonregulatory sampling methods can be reduced. Rockwash–Dnet–visual or kicknet–visual samples have similar diversity to all methods. Reducing sampling methods will save field, sorting, and identification time. Programs can get similar nonregulatory water quality data for less money and effort.

Hydrochemical Characteristics of Water Quality Around Nkalagu Area, Southern Benue Trough, Nigeria Using Multivariate Statistical Analysis

Hydrochemical characteristics of water quality around Nkalagu area has been studied and characterized using multivariate statistical analysis. Eighty water samples were collected in the area from spatially referenced boreholes, hand dug wells abandoned mines, catch pits and rivers located in and around the Nkalagu area and were analyzed for EC, pH, TDS, TH, Ca 2+ , Mg 2+ , Na + , K + , HCO 3 - , Cl - , NO 3 - , SO 4 2- and Fe 2+ according to EPA and APHA standards. Based on mean values, the order of abundance in ions is Cl - &gt; HCO 3 - &gt; SO 4 2 - &gt; NO 3 - , for anions and Na + &gt; Ca 2+ &gt; Mg 2 - &gt; K + , for cations. TDS and Salinity hazard classifications characterized the water in the study area as soft to very hard with low to very high salinity hazard. Principal component analysis (PCA) reduced the hydrochemical data into two principal components which explain 78.553 %, of the total variance that characterize the water quality in relation to the source of its hydrochemistry. Cluster analysis (CA) grouped eighty water samples in the area into eight clusters of similar water quality characteristics related to water-rock interaction, agriculture and anthropogenic sources. Discriminant analysis (DA) showed that the discriminating parameters of water quality in the area are EC, TDS, TH, SO 4 , Cl, Mg, Ca, Na, and HCO 3 and this revealed that water quality in the area is controlled by both geogenic and anthropogenic processes. Keywords: Water Quality, Multivariate analysis, cluster analysis, principal component analysis DOI : 10.7176/JEES/9-11-07 Publication date: November 30 th 2019

Coupled benthic–hyporheic responses of macroinvertebrates to surface water pollution in a gravel-bed river

Interactions between the hyporheic and benthic zones play a vital role in maintaining the integrity of river ecosystems, but simultaneous assessments of hyporheic and benthic macroinvertebrate responses to surface water pollution are limited. We examined how hyporheic (50 cm below surface) and benthic (surface) invertebrates responded to water pollution that originated from a point source (wastewater treatment plant) in a gravel-bed river in Hokkaido, Japan. Dissolved nutrient levels and algal biomass were significantly higher at sample sites down- than upstream of the point source. Furthermore, nitrate concentrations increased gradually from up- to downstream sites, which suggest the presence of diffuse pollution sources in the surrounding areas. Closely synchronized fluctuations of water temperature and similar water quality in the surface and hyporheic zones indicated that the hyporheic zone was highly hydrologically interactive with the surface water. Chloroperlidae (mostly Alloperla ishikariana) had a disproportionately high abundance in the hyporheic zone relative to the benthic zone, regardless of the surface water quality. Numerically dominant invertebrate taxa increased in abundance below the point source of pollution in both the benthic and hyporheic habitats. High N stable isotope ratios (SIR) of the invertebrates in both habitat types indicated that invertebrates assimilated anthropogenic N via the ingestion of pollution-contaminated food resources. End-member mixing analyses based on C SIR demonstrated that assimilation of anthropogenic N occurred because of the increase in available food resources originating from the biofilm. The trophic structure of invertebrates changed less markedly in the hyporheic zone than in the benthic zone, suggesting that the hyporheic assemblage was less sensitive than the benthic assemblage to the changes in surface water quality. Overall, our findings showed that the numeric responses of the invertebrate assemblage to anthropogenic changes in surface water quality were similar and coupled between the benthic and hyporheic zones.

Implications of poor-regulated wastewater treatment systems in the water quality and nutrient fluxes of a subtropical coastal lagoon

Sewage treatment is a way of controlling coastal eutrophication worldwide. Yet is it enough to ensure water quality and avoid the effects of eutrophication? In this study, we hypothesize that sewered and non-sewered regions of Conceição lagoon (Southern Brazil) have similar water quality, due to the poorly designed sewerage system and the lack of effective public policies. The LOICZ (Land–Ocean Interactions in the Coastal Zone) biogeochemical model was used to understand how the lagoon responds to nutrient inputs from the watershed. There was no significant difference in the water quality between the urbanized rivers. Both regions (sewered and non-sewered) showed high concentrations of phosphate, ammonium and fecal coliform. The percentage of urbanization was directly correlated with deoxygenation, nutrients and coliform. Lower concentrations of nutrients and oxic waters were found in the non-urbanized rivers and in the lagoon. As such, biogeochemical and physical processes counterbalance the nutrient inputs. However, the sewage runoff might be fueling the dead zone of the lagoon, since the water residence time and nutrient retention are high. Our results indicate that the sewage treatments are inefficient in preventing the input of organic matter and nutrients to the system. Additionally, new management strategies are required to revert eutrophication, such as the expansion of the serviced area by the sewage system and the improvement of its technology.

The Differences In Benthic Macroinvertebrate Communities When A Comparison Is Made Between Multiple Reaches With Special Attention To Man-Made Structures [Joliet Junior College

The use of macroinvertebrates as indicator organisms is cheap, easy, and a reliable way to determine water quality. To determine the effects on man-made structures on macroinvertebrate communities and stream quality, comparisons were made between macroinvertebrate samples from established open canopy upstream and forested downstream reaches, and adjacent reaches with man-made structures (road bridge and foot bridge). Macroinvertebrates were collected using a D-frame kicknet, following Illinois Riverwatch protocol. There was little difference in Macroinvertebrate Biotic Indices and Shannon Diversity Indices between established and adjacent reaches. However, there were significant differences between EPT/non-EPT and pollution intolerant/tolerant organisms found between all reaches, and between all paired comparisons of the established and adjacent reaches (p&lt; 0.05), except when comparing the forested reach with the road bridge reach (EPT/non-EPT, p=0.583; pollution intolerant/tolerant, p=0.542), the forested reach and the road bridge (EPT/non-EPT, p=0.84), and the forested reach with the adjacent foot bridge reach (EPT/non-EPT, p=0.489). Noticeable differences in taxa distribution occurred between all reaches. Different samples obtained from different reaches indicated varying distribution of taxa, with the forested reach having more high quality EPT taxa and individuals, however all reaches displayed similar water quality of “fair”, with little impact from man-made structures.

Do functional traits of chironomid assemblages respond more readily to eutrophication than taxonomic composition in Chinese floodplain lakes?

Abstract Functional trait-based measures can reflect local environmental conditions and are claimed as promising approaches for environmental monitoring and assessment programs. The chironomid larvae are a diverse and ecologically important group of benthic macroinvertebrates and have a set of functional traits that can be used to assess environmental quality of freshwater ecosystems. However, little is known regarding the relationships between chironomid functional structure and human disturbances, especially at a fine taxonomic resolution. Here, we compared the responses of functional traits and traditional taxonomic measures of chironomid assemblages to eutrophication in the Yangtze floodplain lakes. We found that functional composition showed higher sensitivity and robustness in discriminating the extents of eutrophication than taxonomic composition. Specifically, about half of functional categories examined significantly differed among the lake groups, while only two taxonomical measures (the abundance of Tanytarsini and Polypedilum) are suitable for assessing environmental quality of floodplain lakes. The macrophytic lakes showed higher abundance of scrapers, the small body size and oligotrphic individuals. Whereas the algal lakes were associated with high abundance of eutrophic/hypertrophic chironomids and those with haemoglobin. Chironomid assemblages showed significant differences among four lake groups for both trait-based and taxonomy-based variations, but with larger differences for trait-based groups. The distance-based redundancy analysis (dbRDA) indicated that taxonomic and functional assemblage structures were explained primarily by similar water quality variables (chlorophyll a, transparency and TN), but more functional variation (24.6%) was explained by environmental factors than taxonomic variation (10.9%) in chironomid assemblages. Our results indicated that chironomid trait-based approaches were more sensitive and robust to water quality gradients than taxonomy-based approaches. Therefore, we argued that the chironomid functional traits deserve considerations for biomonitoring programs in the lakes we studied and other freshwater lakes and aquatic ecosystems.

Monitoring stream water quality of Dagwan stream, an important tributary of Dal Lake, Kashmir Himalaya

The assessment of water quality of the Dagwan stream encompassing spatiotemporal variations in physicochemical parameters and all important and relevant hydrological attributes was carried out at five different sites for a period of 1 year (June 2014–May 2015). Statistical techniques like analysis of variance (ANOVA), cluster analysis, and regression analysis applied to datasets revealed spatiotemporal variations. ANOVA and Tukey’s box plot was applied and resulting F values showed the significance of observed variation of each parameter at 5% level of significance in which some parameters do not change significantly. The higher positive and negative relationship among various analyzed water quality parameters were described by general linear regression model (P < 0.0001). The study of physicochemical parameters signify that the quality of its water substantially declines while moving downstream. The water quality sites were classified into significant clusters (clusters I and II) by cluster analysis. Cluster I (sites I and II) is illustrated by similar and better water quality whereas cluster II (sites II, IV, and V) is considered to be of moderately reduced water quality, thereby reflecting the different physicochemical characteristics and quality class. The results from water quality index (WQI) validate that water of the Dagwan stream falls within the excellent to very good category of water quality class. While comparing the results with WHO standards, the water quality was in permissible limits. The escalating level of pollution from upstream to downstream sites indicated slight anthropogenic stress in the downstream areas of the Dagwan stream.

Water Quality Evaluation of the Yangtze River in China Using Machine Learning Techniques and Data Monitoring on Different Time Scales

Unlike developed countries, China has a nationally unified water environment standard and a specific watershed protection bureau to perform water quality evaluation. It is a major challenge to assess the water quality of a large watershed at a wide spatial scale and to make decisions in a scientific way. In 2016, weekly and real-time data for four monitoring indicators (pH, dissolved oxygen, permanganate index, and ammonia nitrogen) were collected at 21 surface water sections (sites) of the Yangtze River Basin, China. Results showed that one site had a relatively low Site Water Quality Index and was polluted for 12 weeks meanwhile. By using expectation-maximization clustering and hierarchical clustering algorithms, the 21 sites were classified. Variable spatiotemporal distribution characteristics for water quality and pollutants were found; some sites exhibited similar water quality variations on the weekly scale, but had different yearly grades. The results revealed polluted water quality for short periods and abrupt anomalies, which imply potential pollution sources and negative effects on water ecosystems. Potential spatio-temporal water quality characteristics, explored by machine learning methods and evidenced by time series and statistical models, could be applied in environmental decision support systems to make watershed management more objective, reliable, and powerful.

Surface water quality assessment based on GIS and hierarchical clustering technique: a case study of Cam Pha Region, Northeast Vietnam

This study is set out to assess surface water quality of three groups of chemical (pH, COD, NH4+), of physics (TSS) and of microorganisms (Coliform) in the Cam Pha mining area, northeast Vietnam. GIS and hierarchical clustering technique were used for interpolation and grouping samples that have similar water quality, respectively. The results showed that surface water quality was heavily contaminated. All of indicators do not meet Vietnam's National Technical Regulations (NTR), especially COD and TSS beyond NTR about ten times at many locations such as TSS at Ha Rang stream, NH4+ at Cau Four River and COD at Khe Sim stream. The worst and best water quality was detected at Ha Rang and Khe Sim and Lep My, Khe Re, and Ong Linh streams, respectively. The results of this study demonstrated GIS and hierarchical clustering technique are effective methods for surface water quality assessments.

Physicochemical parameters and phytoplankton as indicators of the aquatic environment in karstic springs of South China

As the concentrated discharge outlet of an aquifer or groundwater system, a karst spring is partly independent from the aquifer, due to its formation of a pool or lake after outcropping onto the surface. Understanding how to evaluate the unique and sensitive environment of the karst spring is essential for water resource protection. Five karst springs in South China were investigated by analyzing their hydrodynamic conditions, variations in physicochemical parameters, and phytoplankton community structures. Dominated by regional or local groundwater flow, these springs had different catchment area characteristics and hydrogeological conditions. The results showed that, although they had similar water quality, their physicochemical parameters needed to be distinguished and evaluated in different ways in order to determine the cause of the observed degradation in spring water quality. Ca2+, HCO3−, and specific electrical conductivity were the major parameters reflecting the impact of regional flow from the aquifer; pH, dissolved oxygen, and water temperature indicated the local environment in and around the springs; while nitrogen and CODMn both related to the aquifer and local environment, depending on seasonal variation and human activities. The comparison of long-term nitrate data revealed that environmental pressure has increased over time. Water deterioration of Lingshui Spring was attributed to the strong interaction of surface water and groundwater. High nutrient concentrations did not correspond with the highest phytoplankton abundance or the most species. The phytoplankton community structures in the karst springs varied from place to place, depending on the hydrogeological conditions and the surrounding environment. The water environment status, as reflected by the combination of water quality indices and biological indicators, could more comprehensively represent overall water health.

Tailor-made protocol for assessing water quality of irrigation canals: Case study of El-Nubaria canal, Egypt

The aim of this work is to introduce a Tailor-Made-Protocol (TMP) to assess water quality for irrigation canals in accordance to monitoring objectives that deal with pollutant concentrations and loads. The water quality/quantity data collected monthly from 2008 to 2016 for the El-Nubaria canal catchment in Egypt was used as a case study. The developed protocol includes a series of statistical tools employed to facilitate better handling of the collected data and then transform it into useful information. These tools included descriptive statistics and checking compliance with standards, percentage analysis and showing the pollutant loads using box and whisker plots. Finally, cluster analysis was employed to classify the monitoring locations into a number of groups that have similar water quality conditions. The derived clusters were then visualized by using the Geographical Information System (GIS) to draw thematic maps. The success in applying the proposed TMP showed its effectiveness and applicability to check compliance with water quality standards and allocate waste loads from different sources as well as classifying water quality status.

The use of multivariate statistical methods for optimization of the surface water quality network monitoring in the Paraopeba river basin, Brazil.

This study sought to evaluate and propose adjustments to the water quality monitoring network of surface freshwaters in the Paraopeba river basin (Minas Gerais, Brazil), using multivariate statistical methods. A total of 13,560 valid data were analyzed for 19 water quality parameters at 30 monitoring sites, over a period of 5years (2008-2013). The cluster analysis grouped the monitoring sites in eight groups based on similarities of water quality characteristics. This analysis made it possible to detect the most relevant monitoring stations in the river basin. The principal components analysis associated with non-parametric tests and the analysis of violation of the standards prescribed by law, allowed for identifying the most relevant parameters which must be maintained in the network (thermotolerant coliforms, total manganese, and total phosphorus). The discharge of domestic sewage and industrial wastewater, that from mining activities and diffuse pollution from agriculture and pasture areas are the main sources of pollution responsible for the surface water quality deterioration in this basin. The BP073 monitoring site presents the most degraded water quality in the Paropeba river basin. The monitoring sites BP094 and BP092 are located geographically close and they measure similar water quality, so a possible assessment of the need to maintain only one of the two in the monitoring network is suggested. Therefore, multivariate analyses were efficient to assess the adequacy of the water quality monitoring network of the Paraopeba river basin, and it can be used in other watersheds.

Can the presence of curved forms of the diatom Aulacoseira ambigua in the Nile (Egypt) and Vaal (South Africa) Rivers be ascribed to similar water quality conditions?

Spiral colonies of the diatom Aulacoseira ambigua were assigned the rank of forma (Aulacoseira ambigua f. japonica). This spiral-shaped, colonial, centric diatom has limited geographical distribution and is currently reported to occur in only a few countries in the world. In Africa this species was described for the first time from the Vaal River, South Africa, but recent research on the Nile River also revealed its presence in Egypt. Physical and chemical data on water quality in these two river systems were compared to determine whether the presence of this uncommon ‘phenoecodeme’ could be ascribed to similar environmental conditions. Results indicate that the rivers are dissimilar with regard to many variables, but both rivers provide turbid, warm and eutrophic waters with medium to high mineral content and it was concluded that these factors favour and sustain the growth of this curved form.

Nutrient Reduction in Agricultural Green Infrastructure: An Analysis of the Raccoon River Watershed

Agricultural intensification has had the undesirable effect of degrading water quality throughout the United States. Nitrate pollution presents a difficult problem for rural and urban communities, and it contributes to the immense Gulf of Mexico Hypoxia Zone. Current U.S. policy prohibits regulation of agricultural runoff because it is a nonpoint source. The Raccoon River Watershed upstream of Des Moines, Iowa, USA has some of the highest nitrate levels in the nation, and the drinking water utility in Des Moines unsuccessfully pursued litigation against drainage districts in the watershed. We propose a cooperative solution between urban residents and upstream rural residents—namely, the installation of agricultural green infrastructure in the form of riparian buffers throughout the watershed enabled by the principles of water quality trading. We compare this distributed, green approach with a centralized, gray approach (i.e., building a new nitrate removal facility at the drinking water utility). Using terrain analysis, we determined that first-order streams are the most fitting location for riparian buffers. We estimate the buffer installation to cost between $155–$185 million; maintenance of the current nitrate removal facility will cost $72 million, while a new facility could cost up to $184 million. Riparian buffer installation offers more indirect, non-quantified benefits than maintaining or building new centralized, gray treatment (e.g., living-wage jobs and in-stream water quality improvement). Our analysis could act as a model for water quality trading and distributed agricultural green infrastructure in other communities facing similar water quality challenges.

Multivariate statistical characterization of groundwater quality in Fesdis, East of Algeria

AbstractThis study is a contribution to the knowledge of hydrochemical properties of the groundwater in Fesdis Plain, Algeria, using multivariate statistical techniques including principal component analysis (PCA) and cluster analysis. 28 samples were taken during February and July 2015 (14 samples for each month). The principal component analysis (PCA) applied to the data sets has resulted in four significant factors which explain 75.19%, of the total variance. PCA method has enabled to highlight two big phenomena in acquisition of the mineralization of waters. The main phenomenon of production of ions in water is the contact water-rock. The second phenomenon reflects the signatures of the anthropogenic activities. The hierarchical cluster analysis (CA) in R mode grouped the 10 variables into four clusters and in Q mode, 14 sampling points are grouped into three clusters of similar water quality characteristics.

Removal of Woody Riparian Vegetation Substantially Altered a Stream Ecosystem in an Otherwise Undisturbed Grassland Watershed

Riparian zones are key interfaces between stream and terrestrial ecosystems. Yet, we know of no whole-watershed experiments that cut only woody vegetation in the riparian zone in an otherwise intact watershed to isolate the role of riparian zones on stream ecology. We removed all of the woody riparian vegetation (from 10- and 30-m-wide buffers in headwaters and main channels, respectively) for 5 km of stream in a single watershed while leaving the remainder of the grassland watershed un-impacted. We assessed water chemistry changes 3 years before and 3 years after riparian wood removal and in two neighboring control watersheds with a before–after, control-impact design and analysis. Riparian woody removal caused 10–100-fold increases in mean stream water nitrate concentrations and pulses of high nitrate for 3 years thereafter. Other nutrients and total suspended solids increased 2–25 times for the 3 years of post-removal. In-stream rates of gross primary production, ecosystem respiration, and net ecosystem production had large treatment effect sizes but also high variance among samples. Past studies of whole-watershed deforestations showed similar water quality responses to our riparian deforestation. Riparian zones of grassland streams are sensitive to disturbance and likely impart relatively greater influence on stream structure and function than the upslope of the watershed. Our results further emphasize the role of riparian zones in biogeochemically linking aquatic and terrestrial habitats.