Temporal Patterns Of Water Quality Research Articles

A new perspective on water quality: Exploring spatial and temporal patterns of impaired waters

Managing surface water quality is a global challenge, and understanding spatial and temporal patterns of water quality is a key component to effective management. However, analysis of spatiotemporal patterns of impaired waters over broad areas is sparse due to disparate water quality data and variable water quality standards. Thus, here we leverage the Alabama 303(d) List of impaired waters to present a new perspective for investigating spatiotemporal water quality patterns. Every two years, each state in the United States is required to assess its surface water quality and compile a list of impaired waterbodies, meaning waters that do not meet water quality standards for their designated usage – referred to as the 303(d) List. The purpose of the 303(d) List is to identify impaired waters so that corrective action can be taken to reduce pollutant loads and, ultimately, improve water quality. Using GIS, a space time cube was created to analyze and visualize spatiotemporal patterns of the impaired rivers added to the Alabama 303(d) Lists from 1996 to 2022. For this analysis, the percentage of river length impaired out of the total river length, and number of times each impairment cause was listed, were summarized within Alabama sub-basins (Hydrologic Unit Code 8) (n = 51). Trend and hot spot analyses were conducted on the river impairment and causes. There was an up trend in river impairment for eight sub-basins across the state and a downtrend in one sub-basin. Over half of the sub-basins with an up trend in impairment also had an up trend in the number of times pathogens was listed as a cause of impairment. Additionally, coastal sub-basins were found to be a hot spot for river impairment. Interestingly, there was a down trend in the number of times nutrients, ammonia, and siltation were listed as a cause of impairment at the state and sub-basin scales of analysis. Altogether, these findings show the use of spatiotemporal pattern analysis of impaired waters and can indicate where, both spatially and by pollutant, management should prioritize water quality improvement efforts.

Efectos de las actividades antrópicas sobre parámetros metabólicos en un bivalvo invasor y otro nativo en el tramo inferior del río Paraná

The relationship between anthropogenic pollution, geochemistry and natural dynamics of freshwater ecosystems determine the spatial and temporal patterns of water quality. Human activities and the introduction of exotic species are the main causes of the decrease in biological diversity. The introduction and spread of the invasive bivalve Corbicula fluminea endangers the presence of the native bivalve Diplodon delodontus. Through oxidative stress indicators, it is possible to quantify the response of organisms to changes in physical-chemical, natural and/or anthropogenic variables. Therefore, the objective was to interpret the effect of changes in physical-chemical variables, contaminants and/or xenobiotics on the metabolic responses of C. fluminea and D. delodontus on the Paraná de las Palmas river. Randomly, we established a sampling point to collect individuals (60 of invasive and 10 of native bivalve) for the assembly of 10 cages by species and placement site in September 2018. In June and September 2019, five cages of each species were extracted at random. In water, physical-chemical parameters and metals were measured, and in the organs of both species, protein concentration, glycogen, lipid damage, reduced glutathione content, enzymatic activity of catalase and glutathione-S-transferase. In general, the physical-chemical and metal parameters increased significantly from June to September. Metals exceeded freshwater quality guideline levels for the protection of aquatic life. In relation to the changes in these variables, the metabolic parameters differed between organs and species from June to September. The gills and digestive gland of C. fluminea showed higher metabolic responses and faster than D. delodontus. The study of invasive and native species through the measurement of multiple variables is a useful tool to characterize the environment, with application prospects in water quality monitoring and conservation studies.

A spatiotemporal analysis of water quality characteristics in the Klip river catchment, South Africa.

Understanding the spatial and temporal patterns of water quality is central to its management as it provides information essential to the restoration as well as protection of water resources. The main objectives of this study were (i) to analyze the spatial and temporal trends of water quality and (ii) to identify the critical sources of pollution in the Klip River catchment (KRC). Water samples were collected at 12 sampling points along the Klip River, monthly from February 2016 to January 2017 and analyzed using inductively coupled plasma mass spectrometry (ICP-MS) and spectrophotometry for heavy metals and nutrients, respectively. Multivariate statistical techniques (cluster analysis and discriminant analysis) were used to delineate homogeneous water quality zones and seasons, and principal component analysis was used to identify pollution sources. Comprehensive pollution index (CPI) was also computed to classify the overall pollution of the river. The spatial grouping yielded two homogenous water quality zones namely upstream and downstream. Temporal grouping yielded two clusters, which were attributed to the effects of the El Nino (2015/16 season) and La Nina phenomena (2016/17 season). The CPI revealed that the KRC was critically polluted in the upstream for domestic (162.16-323.28) and aquatic uses (617.70-837.09) in both the 2015/2016 and 2016/2017 seasons. It can be concluded that pollutants, which influence water quality in the KRC in one season and/or location, may not necessarily be the same in the other season or location. Therefore, there is need to develop a water quality management plan in the KRC that targets the most impaired uses, pollutants of priority, and the critically polluted areas.

Big Groundwater Data Sets Reveal Possible Rare Contamination Amid Otherwise Improved Water Quality for Some Analytes in a Region of Marcellus Shale Development.

Eleven thousand groundwater samples collected in the 2010s in an area of Marcellus shale-gas development are analyzed to assess spatial and temporal patterns of water quality. Using a new data mining technique, we confirm previous observations that methane concentrations in groundwater tend to be naturally elevated in valleys and near faults, but we also show that methane is also more concentrated near an anticline. Data mining also highlights waters with elevated methane that are not otherwise explained by geologic features. These slightly elevated concentrations occur near 7 out of the 1,385 shale-gas wells and near some conventional gas wells in the study area. For ten analytes for which uncensored data are abundant in this 3,000 km2 rural region, concentrations are unchanged or improved as compared to samples analyzed prior to 1990. Specifically, TDS, Fe, Mn, sulfate, and pH show small but statistically significant improvement, and As, Pb, Ba, Cl, and Na show no change. Evidence from this rural area could document improved groundwater quality caused by decreased acid rain (pH, sulfate) since the imposition of the Clean Air Act or decreased steel production (Fe, Mn). Such improvements have not been reported in groundwater in more developed areas of the U.S.

Temporal patterns of water quality in the Pantanal floodplain and its contributing Cerrado upland rivers: implications for the interpretation of freshwater integrity

Water quality time series available for major tropical floodplains commonly have low temporal resolutions and irregular sampling frequencies. Here we examine such data using singular spectrum analysis, a non-parametric time series analysis technique, to assess the typical cyclical variations and long-term trends in upland Cerrado and lowland floodplain reaches of three rivers that are tributaries to the Pantanal in Brazil to evaluate ecological state and impact level, and develop recommendations for improved monitoring of Cerrado–Pantanal river systems. Both upland and lowland reaches have their average water quality cycles linked to a monocyclical hydrological regime. Amplitudes of nutrient concentrations (N, P) and Turbidity are higher in the uplands, whereas cyclical oxygen variations are up to two times higher in the floodplain reaches. SSA showed that trend extraction is possible for parameters with lower intra-annual variations and were found to be partially opposing (oxygen) in upland (negative trend) and floodplain (positive trend) stations. Land use intensification in the uplands is reflected by N concentrations in upland reaches. In the floodplain, the Paraguay river was found under a slight TN enrichment regime of about 0.02 mg L−1 per year between 1995 and 2009. Assuming a fixed budget for institutional water quality monitoring, we recommend a reduction of the 150 registered sampling gauges by environmental agencies in the Brazilian Pantanal and its contribution area, 95 % of them with less than four samples per year, in favor of using the same resources for increased sampling frequency at a smaller number of sites.

Nitrate sinks and sources as controls of spatio-temporal water quality dynamics in an agricultural headwater catchment

Abstract. Several controls are known to affect water quality of stream networks during flow recession periods, such as solute leaching processes, surface water–groundwater interactions as well as biogeochemical in-stream turnover processes. Throughout the stream network, combinations of specific water and solute export rates and local in-stream conditions overlay the biogeochemical signals from upstream sections. Therefore, upstream sections can be considered functional units which could be distinguished and ordered regarding their relative contribution to nutrient dynamics at the catchment outlet. Based on snapshot sampling of flow and nitrate concentrations along the stream in an agricultural headwater during the summer flow recession period, we determined spatial and temporal patterns of water quality for the whole stream. A data-driven, in-stream-mixing-and-removal model was developed and applied for analysing the spatio-temporal in-stream retention processes and their effect on the spatio-temporal fluxes of nitrate from subcatchments. Thereby, we have been able to distinguish quantitatively between nitrate sinks, sources per stream reaches, and subcatchments, and thus we could disentangle the overlay of nitrate sink and source signals. For nitrate sources, we determined their permanent and temporal impact on stream water quality and for nitrate sinks, we found increasing nitrate removal efficiencies from upstream to downstream. Our results highlight the importance of distinct nitrate source locations within the watershed for in-stream concentrations and in-stream removal processes, respectively. Thus, our findings contribute to the development of a more dynamic perception of water quality in streams and rivers concerning ecological and sustainable water resource management.

낙동강 중류 보 구간에서의 시 · 공간적 수질 분포 특성 연구

AbstractWe investigated the spatial and temporal patterns of water quality in the Gangjung-Goryoung weir that is located in the middle area of the Nakdong river, Korea. The monitoring results indicated that there are discernible vertical differences in water quality during the pre- and post-monsoon periods (May to September). During this period, it was observed that the weak thermal stratification formed at the maximum level, and pH, Chl-a, and DO concentrations in the surface layer were higher than those in the bottom layer. This vertical difference was especially noticeable for DO concentrations: there were DO depletions at the bottom layer in late June to early August. During the summer monsoon period with heavy rainfall, there was a decline in vertical differences in water quality. From this study, it was suggested that continuous monitoring of vertical profiles could become a useful tool for identifying the spatial and temporal distributions of water quality and for developing the best management policy for water quality in the Nakdong river.Key words: Algal bloom, DO depletion, Gangjung-Goryoung weir, Nakdong river, Thermal stratification

Spatial and temporal characterizations of water quality in Kuwait Bay

The spatial and temporal patterns of water quality in Kuwait Bay have been investigated using data from six stations between 2009 and 2011. The results showed that most of water quality parameters such as phosphorus (PO4), nitrate (NO3), dissolved oxygen (DO), and Total Suspended Solids (TSS) fluctuated over time and space. Based on Water Quality Index (WQI) data, six stations were significantly clustered into two main classes using cluster analysis, one group located in western side of the Bay, and other in eastern side. Three principal components are responsible for water quality variations in the Bay. The first component included DO and pH. The second included PO4, TSS and NO3, and the last component contained seawater temperature and turbidity. The spatial and temporal patterns of water quality in Kuwait Bay are mainly controlled by seasonal variations and discharges from point sources of pollution along Kuwait Bay’s coast as well as from Shatt Al-Arab River.

Identification of temporal and spatial variations of water quality in Sanya Bay, China by three-way principal component analysis

A large data set obtained by a 1-year monthly determination of water quality from Sanya Bay, South China Sea, was treated by three-way principal component analysis aimed at exploring the spatial and temporal patterns of water quality in Sanya Bay. Tucker3 model of optimum complexity (2, 2, 1) explaining 33.18% of the data variance, allowed interpretation of the data information in three modes. The model explained spatial and temporal variation trends in terms of water quality variables during the study period. Water quality in sampling station (S2) Sanya River was mainly influenced by Sanya River, and water quality in other stations (S1, S3-S10) were mainly influenced by the waters in South China Sea. The results delineated the mouth of Sanya River as critical from pollution point of view. The dry season from October to the next April and rainy season from May to September have different influences on water quality in Sanya Bay. The information extracted by the three-way models would be very useful to regional agencies in developing a strategy to carry out scientific plans for resource use based on marine system functions.

Spatial and Temporal Patterns of Water Quality in Cullera Bay

The Júcar River, characterized by a very irregular freshwater flow, discharges into the Spanish Mediterranean coastal waters. However, the flow at its mouth is usually insignificant due to the overexploitation of upstream water. Under normal conditions, the final stretch of the river (downstream from the Cullera weir) is nurtured only by water released from the weir and small discharges from lateral irrigation channels. During periods of heavy rain, however, a significant amount of water flows through the Cullera weir. An analysis of data acquired during several field campaigns in Cullera Bay clearly reveals a zonal distribution of nutrients and chlorophyll-a within the bay: a southern area of continental influence, located near the mouth of the Júcar River; a region affected by karst filtrations and minor freshwater inputs, located to the north of the bay around Cullera Cape; and a third zone in between, characterized by higher salinities. Spatial salinity distribution is indicative of the spatial distribution of some of the nutrients discharged by the river, particularly nitrite, nitrate, orthosilicic acid and total phosphorus (TP), since it has been shown that their behavior is inverse to that of salinity. However, neither soluble reactive phosphorus (SRP) nor ammonium, which are mainly affected by biological activity, show this type of behavior. Five different conditions/scenarios were identified during the overall sampling period based on the time-series analysis of wind parameters, rainfall, freshwater flow, salt-wedge thickness at the measuring station on the river, and by comparing the average surface salinity at the sea stations with the values obtained at the coastal stations.

Spatial and temporal patterns of water quality along the estuarine salinity gradient of the Scheldt estuary (Belgium and The Netherlands): results of an integrated monitoring approach

This paper presents the results of 7 years of integrated monitoring along the Scheldt estuary. The combination of two datasets resulted in a full description of the estuaries water quality parameters from the mouth to the upper boundary, including an extended fresh water tidal part. A synthesis of the monitoring results and all relevant ecological knowledge on the Scheldt allowed to identify opportunities to optimize its management. The results show that the effect of discharge on salinity has a distinct maximum in the polyhaline to mesohaline transition area. Oxygen conditions, nitrogen removal and phytoplankton regulation can be enhanced and improved through management measures within the estuary. To lower carbon and phosphorous loads however measures should be taken within the catchment. To restore most of its ecological functions the estuary needs more space. Optimal locations to address specific functions can be derived from the monitoring results.

A temperate, tidal lake‐wetland complex 2. Water quality and implications for zooplankton community structure

Lakes Waihola and Waipori are shallow, coastal, tidal lakes that experience wind‐induced sediment resuspension, saline intrusions, and high inputs of nutrients. To determine the influence of externally‐driven, physical factors on spatial and temporal patterns of water quality in the two lakes, meteorological, hydrological, and water quality data were collected over 1 year. Multivariate analyses indicated that wind energy was driving the main water quality gradient in the lakes, which was primarily related to wind‐induced resuspension of lake sediments. The major, seasonally regulated, non‐tidal freshwater inflow was important in determining nutrient and salinity gradients in the lakes. The main nutrient inputs to the system were identified as the regulated, non‐tidal inflow (the upper Waipori River) and the tidal inflow (lower Waipori River). The impact of water quality gradients on zooplankton community structure in the lakes was assessed by canonical multivariate methods. Salinity gradients, caused by seasonal saltwater intrusions, were strongly related to zooplankton community structure in the lakes. Nutrient gradients (indicative of trophic state) were also related to zooplankton community structure. Although wind‐induced sediment resuspension had the largest impact on water quality in the lakes, it had little impact on the zooplankton community structure in either lake. The relationships between water quality and zooplankton community structure were confounded in Lake Waipori because of its very short hydraulic residence time (annual mean =1.9 days). Zooplankton community structure was resilient to short‐term changes in suspended particulate matter concentrations but not to seasonal changes in salinity. The results of this study support others which have shown impacts of even relatively small variations in salinity on the structure of zooplankton communities. This highlights the vulnerability of zooplankton communities in coastal lakes and wetlands to increasing salinity resulting from sea level rise and global climate change.

A regional organism exchange model for simulating fish migration

Abstract A grid-based, spatially-explicit Regional Organism Exchange (ROE) model is presented as a framework for integrating aquatic ecosystems and fish population processes at the landscape level. Active fish movements across a grid cell boundary were predicted, based on environmental tolerance ranges. The model was designed to be easily modified for any aquatic system, migratory life-stage, or trophic community. ROE was specifically developed to understand how large-scale physical patterns (i.e., tidal and freshwater intrusions) and landscape biological processes (i.e., primary production and foraging behavior) control migration of stenohaline fishes in the estuarine lagoon of Laguna de Terminos, Mexico. A migration response matrix for temperature, salinity, food availability, birth, and mortality was used to control cell-to-cell population movements. Internal cell processes included logistic population growth, trophic interactions, and ecosystem feedback parameters. Output data maps from the ROE model showed how population spatial distributions were linked to spatial and temporal patterns of water quality. However, the most significant parameter affecting long-term population stability was birth rate; an internal cell variable. It was concluded that the simulation of large, density-dependent, spatial processes such as migration can be understood with a grid-based mechanistic ROE model because its rule-based design for movement allowed organisms to respond to ecological processes and adjust to changing environmental conditions.