463 research outputs found

    The impact of agricultural activities on water quality: a case for collaborative catchment-scale management using integrated wireless sensor networks

    No full text
    The challenge of improving water quality is a growing global concern, typified by the European Commission Water Framework Directive and the United States Clean Water Act. The main drivers of poor water quality are economics, poor water management, agricultural practices and urban development. This paper reviews the extensive role of non-point sources, in particular the outdated agricultural practices, with respect to nutrient and contaminant contributions. Water quality monitoring (WQM) is currently undertaken through a number of data acquisition methods from grab sampling to satellite based remote sensing of water bodies. Based on the surveyed sampling methods and their numerous limitations, it is proposed that wireless sensor networks (WSNs), despite their own limitations, are still very attractive and effective for real-time spatio-temporal data collection for WQM applications. WSNs have been employed for WQM of surface and ground water and catchments, and have been fundamental in advancing the knowledge of contaminants trends through their high resolution observations. However, these applications have yet to explore the implementation and impact of this technology for management and control decisions, to minimize and prevent individual stakeholder’s contributions, in an autonomous and dynamic manner. Here, the potential of WSN-controlled agricultural activities and different environmental compartments for integrated water quality management is presented and limitations of WSN in agriculture and WQM are identified. Finally, a case for collaborative networks at catchment scale is proposed for enabling cooperation among individually networked activities/stakeholders (farming activities, water bodies) for integrated water quality monitoring, control and management

    Estimating Total Phosphorus and Total Suspended Solids Loads from High Frequency Data

    Get PDF
    Frequently measured turbidity was examined as a surrogate for total phosphorus (TP) and total suspended solids (TSS) loads at two locations in the Little Bear River, Utah, USA. Using regression techniques, equations were developed for TP and TSS as functions of turbidity. The equations accounted for censored data, and additional explanatory variables to represent hydrological conditions were considered for inclusion in the equations. By using the resulting surrogate relationships with high frequency turbidity measurements, high frequency estimates of TP and TSS concentrations were calculated. To examine the effect of sampling frequency, reference loads were determined from the concentration records for two water years. The concentration records were artificially decimated to represent various frequencies of manual grab sampling from which annual loads were calculated and compared to the reference loads

    Improving Surrogate Monitoring Techniques for Suspended Sediment

    Get PDF
    The quality of water of our nation’s rivers and streams is important to many vital uses including drinking water treatment, recreation, and the natural environment. Water quality can be severely impacted by the quantity and type of suspended sediment found therein. Because suspended sediment can be associated with many other contaminants that degrade water quality, it is noted as the most common impairment to water quality in the United States. Suspended sediment can cause significant ecological impacts to the chemical and biological characteristics of surface waters. The ability to accurately quantify suspended sediment concentrations at the appropriate time(s) and location(s) is critical in assessing whether streams are meeting their designated beneficial uses and in implementing and evaluating watershed management and mitigation plans and restoration efforts. Currently, new methods for quantifying suspended sediment concentrations use mathematical and statistical techniques to relate turbidity and suspended sediment and have been shown to be affected by several factors, including the size and characteristics of suspended sediment particles. In this research we used turbidity as a surrogate (substitute) for suspended sediment at six locations in the Little Bear River, Utah, U.S.A. We also examined the differences between single-point and width and depth integrated suspended sediment sampling at two sites. This was used to develop a method to account for the differences and improve the resulting estimates of suspended sediment concentrations. Statistical techniques were used to assess—in probabilistic terms—the duration and magnitude of potential water quality criteria exceedance. Findings highlight that among some monitoring locations with wide geographic distances, turbiditysuspended sediment relationships are not site-specific for the more frequent (90th percentile) but lower (\u3c50 \u3eNTU) turbidity values. Comparisons of point measures of turbidity and width and depth integrated suspended sediment samples revealed that suspended sediment is homogenous at their respective stream cross sections for 90% and 99% of the time at sites 2 and 6, respectively. The results are applicable to water managers who are charged with the determination of attainment or exceedance of water quality standards

    Estimating Suspended Solids and Phosphorus Loading in Urban Stormwater Systems Using High-Frequency, Continuous Data

    Get PDF
    The introduction of pavement, buildings, and other impervious surfaces to urban landscapes greatly influences the quantity and quality of urban stormwater runoff. In this study, we designed and implemented modern stormwater monitoring technologies to establish a “smart” stormwater sensor network within the Northwest Field Canal (NWFC), an urban water conveyance located in Logan, Utah, USA. This network was designed to collect flow and water quality data at high frequencies and simultaneously at multiple locations. The observatory’s innovative method of inter-site communication and changing sampling frequencies during storm events was able to capture short duration events at the upstream and downstream ends of the NWFC and at multiple outfalls in the canal simultaneously without human intervention. We then investigated statistical regression models between turbidity and TSS so as to predict TSS at high frequencies. Finally, the addition of the high-frequency discharge data in the calibration procedure for a stormwater simulation model developed using the Environmental Protection Agency’s Stormwater Management Model did little to improve model performance at the downstream end of the canal, but did provide important insight into the overall contribution of discharge from individual stormwater outfalls to the NWFC. The results of this study inform water professionals on how to build and operate automated monitoring systems and how to create high-frequency estimates of TSS and TP loads in urban water systems

    Advances in Catchment Science, Hydrochemistry, and Aquatic Ecology Enabled by High-Frequency Water Quality Measurements

    Get PDF
    High-frequency water quality measurements in streams and rivers have expanded in scope and sophistication during the last two decades. Existing technology allows in situ automated measurements of water quality constituents, including both solutes and particulates, at unprecedented frequencies from seconds to subdaily sampling intervals. This detailed chemical information can be combined with measurements of hydrological and biogeochemical processes, bringing new insights into the sources, transport pathways, and transformation processes of solutes and particulates in complex catchments and along the aquatic continuum. Here, we summarize established and emerging high-frequency water quality technologies, outline key high-frequency hydrochemical data sets, and review scientific advances in key focus areas enabled by the rapid development of high-frequency water quality measurements in streams and rivers. Finally, we discuss future directions and challenges for using high-frequency water quality measurements to bridge scientific and management gaps by promoting a holistic understanding of freshwater systems and catchment status, health, and function

    Hydrologic Information Systems: Advancing Cyberinfrastructure for Environmental Observatories

    Get PDF
    Recently, community initiatives have emerged for the establishment of large-scale environmental observatories. Cyberinfrastructure is the backbone upon which these observatories will be built, and scientists\u27 ability to access and use the data collected within observatories to address research questions will depend on the successful implementation of cyberinfrastructure. The research described in this dissertation advances the cyberinfrastructure available for supporting environmental observatories. This has been accomplished through both development of new cyberinfrastructure components as well as through the demonstration and application of existing tools, with a specific focus on point observations data. The cyberinfrastructure that was developed and deployed to support collection, management, analysis, and publication of data generated by an environmental sensor network in the Little Bear River environmental observatory test bed is described, as is the sensor network design and deployment. Results of several analyses that demonstrate how high-frequency data enable identification of trends and analysis of physical, chemical, and biological behavior that would be impossible using traditional, low-frequency monitoring data are presented. This dissertation also illustrates how the cyberinfrastructure components demonstrated in the Little Bear River test bed have been integrated into a data publication system that is now supporting a nationwide network of 11 environmental observatory test bed sites, as well as other research sites within and outside of the United States. Enhancements to the infrastructure for research and education that are enabled by this research are impacting a diverse community, including the national community of researchers involved with prospective Water and Environmental Research Systems (WATERS) Network environmental observatories as well as other observatory efforts, research watersheds, and test beds. The results of this research provide insight into and potential solutions for some of the bottlenecks associated with design and implementation of cyberinfrastructure for observatory support

    Sensors in the stream: the high-frequency wave of the present

    Get PDF
    New scientific understanding is catalysed by novel technologies that enhance measurement precision, resolution or type, and that provide new tools to test and develop theory. Over the last 50 years, technology has transformed the hydrologic sciences by enabling direct measurements of watershed fluxes (evapotranspiration, streamflow) at time scales and spatial extents aligned with variation in physical drivers. High frequency water quality measurements, increasingly obtained by in-situ water quality sensors, are extending that transformation. Widely available sensors for some physical (temperature) and chemical (conductivity, dissolved oxygen) attributes have become integral to aquatic science, and emerging sensors for nutrients, dissolved CO2, turbidity, algal pigments, and dissolved organic matter are now enabling observations of watersheds and streams at timescales commensurate with their fundamental hydrological, energetic, elemental, and biological drivers. Here we synthesize insights from emerging technologies across a suite of applications, and envision future advances, enabled by sensors, in our ability to understand, predict, and restore watershed and stream systems

    A smart city-smart bay project - establishing an integrated water monitoring system for decision support in Dublin Bay

    Get PDF
    Environmental and water quality monitoring is key to measuring and understanding the chemical and biological quality of water and for taking reactive remedial action. Over the coming years, monitoring of water bodies will increase within Europe, in order to comply with the requirements of the Water Framework Directive (WFD, Council Directive 2000/60/EC), and globally owing to pressure from climate change. The establishment of high quality long-term monitoring programmes is regarded as essential if the implementation of the WFD is to be effective. However, the traditional spot/grab sampling using conventional sampling and laboratory based techniques can introduce a significant financial burden, and is unlikely to provide a reasonable estimate of the true maximum and/or mean concentration for a particular physico-chemical variable in a water body with marked temporal variability. When persistent fluctuations occur, it is likely only to be detected through continuous measurements, which have the capability of detecting sporadic peaks of concentration. The aim of this work is to demonstrate the potential for continuous monitoring data in decision support as part of a smart city project. The multi-modal data system shows potential for low-cost sensing in complex aquatic environments around the city. Continuous monitoring data from both visual and water quality sensors is collected and data from grab samples collected support the observations of trends in water quality
    • 

    corecore