1,720,973 research outputs found
Quantifying the environmental impact of pollutant plumes from coastal rivers with remote sensing and river basin modelling
No full textCoastal regions contaminated by polluted river water leaving inland river basins can be difficult to monitor due to their size and remoteness, but it is important to quantify the impact of such pollution to manage for coastal sustainability. In this research, we demonstrate how river plumes can be monitored and analysed by a combination of remote sensing and river basin modelling to estimate their spatial, temporal, and water quality characteristics. Our results show that multispectral remote sensing is able to differentiate the water quality characteristics and two-dimensional spatial characteristics between plumes from four discharge locations along the coast of Campania, Italy. Our results also show that river basin modelling, when informed by land cover, land use and wastewater treatment plant (WWTP) data, is able to estimate the plume volume, and pollutant load, attributed to rainfall-runoff and wastewater-discharge for each of the discharges. This research documents a new method for combining remote sensing and watershed modelling to quantify the environmental impact of pollution from coastal rivers
Characterization of hyporheic exchange drivers and patterns within a low-gradient, first-order, river confluence during low and high flow
Full text linkConfluences are nodes in riverine networks characterized by complex three-dimensional changes in flow hydrodynamics and riverbed morphology, and are valued for important ecological functions. This physical complexity is often investigated within the water column or riverbed, while few studies have focused on hyporheic fluxes, which is the mixing of surface water and groundwater across the riverbed. This study aims to understand how hyporheic flux across the riverbed is organized by confluence physical drivers. Field investigations were carried out at a low gradient, headwater confluence between Baltimore Brook and Cold Brook in Marcellus, New York, USA. The study measured channel bathymetry, hydraulic permeability, and vertical temperature profiles, as indicators of the hyporheic exchange due to temperature gradients. Confluence geometry, hydrodynamics, and morphodynamics were found to significantly affect hyporheic exchange rate and patterns. Local scale bed morphology, such as the confluence scour hole and minor topographic irregularities, influenced the distribution of bed pressure head and the related patterns of downwelling/upwelling. Furthermore, classical back-to-back bend planform and the related secondary circulation probably affected hyporheic exchange patterns around the confluence shear layer. Finally, even variations in the hydrological conditions played a role on hyporheic fluxes modifying confluence planform, and, in turn, flow circulation patterns
Real estate values and ecosystem services: Correlation levels
Full text linkThe market value of urban property depends not only on its specific characteristics, but also on reference macro-economic variables such as socio-demographic, productive, infrastructural, and environmental quality and associated ecosystem services. The links between urban property real estate values and ecosystem services, particularly those generated by urban forests, are not yet sufficiently investigated and hence are the focus of this research. The study site is the City of Syracuse, New York, USA, with well characterized urban forest ecosystem services and property values. The study correlated real estate values and parameters of economic condition (per-capita income), ecosystem services (carbon sequestration), and urban forestry system (tree canopy area). The median home value correlation with both per capita income had an R2 = 0.8748 and with carbon sequestration it had an R2 = 0.7757. The data was obtained in the online i-Tree Landscape tool. Geographic information systems analysis was used to create maps that support analysis of the correlation levels between the involved variables
Remote sensing for environmental forensics: Thermal infrared images capture different surface temperatures in pollutant pools and dosed soils due to volatilization
No full textThe challenges of in-situ monitoring of contaminated landscapes include the rapid assessment of large areas for potential pollutants and their potential health risk due to volatilization. This research tested in a laboratory setting if thermal infrared remote sensing can discriminate between areas with volatilizing chemicals. Five pollutants of metal salts were prepared by mixing antimony with a solvent of hydrochloric acid, and cobalt, lead, nickel, and zinc with a solvent of nitric acid. Four pollutants of hydrocarbons, at two different concentrations, were prepared by mixing diesel, gasoline, motor oil, and olive oil with a solvent of acetone. The pollutants and solvents were in liquid pools and dosed on soils in petri dishes, each pollutant in a separate container, along with controls of a deionized water pool and un-dosed soil. The petri dishes were arranged in arrays, spaced to create intermediate areas without volatilization, and placed adjacent to a fume hood that created an updraft to remove volatilization products. The cooling of the pollutant surface due to volatilization was confirmed using thermocouple-based monitoring of in-situ kinetic temperature, and the thermal infrared radiometric temperature had a strong correlation with kinetic temperature. Based on two-tailed unpaired t tests of temperatures from 256 pixels for each petri dish, with a 0.05 alpha, 97% of the 66 polluted pool pairs had statistically different temperatures, and 85% of the 66 dosed soil pairs had statistically different temperatures. This study validated that thermography can differentiate between pollutant types and concentrations based on volatilization affecting temperature and thereby extend the remote sensing toolbox for environmental forensics. Further work is required to scale up this thermography technique from the relatively simple laboratory setting to more complex field applications
HIERARCHICAL MONITORING OF WATER QUALITY: COORDINATING THE SPATIOTEMPORAL RESOLUTION OF MULTILAYER AND MULTISPECTRAL SENSORS TO CHARACTERIZE POLLUTION
No full textCoastal Water Pollution Characterization: Enhanced Situational Awareness Through Multiscale Data Acquisition and Analysis
No full textCyanobacterial Biomonitoring in Lake Avernus During the COVID-19 Pandemic: Integrating Remote Sensing and Field Data for Pollution Source Detection
No full textIn the context of environmental monitoring studies, the complex dynamics of environmental systems, constrained by the distribution, intensity and interaction of multiple sources, limits the ability to detect pollution phenomena and to identify their sources. The deployment of multidisciplinary, multilevel and multi-factorial strategies supports the identification of the links between the pollutants’ sources and targets. Our new biomonitoring strategy, based on the integration of remote (satellite) and proximal (drone) sensing monitoring data with field data (bio/chemical analyses) and focused on the use of cyanobacteria as bioindicators of pollution, was implemented and was validated through its application on a test-bed area, i.e., Lake Avernus (Campania Region, Southern Italy). A long-term analysis of multispectral remote sensing observations centred on the Lake Avernus area highlighted the periodicity and seasonality of cyanobacterial bloom events over the time interval 2019-2021. However, a sudden change of characteristics, observable through remotely sensed data, was evidenced during the first and major lockdown related to the COVID-19 pandemics, in year 2020. This sudden change depended on the drastic modification of human habits and a reduction in pollutant emissions, as widely reported by the scientific literature. During the same lockdown period, the opportunity to collect samples in the field allowed to identify an unusual progression of Microcystis' bloom, whose dynamics is triggered by the existing anthropogenic sources and the evolution of environmental parameters, that can stimulate the blooming events. This work shows and demonstrates how pollution attribution can be achieved using remote sensing of cyanobacteria, which are excellent bioindicators due to their sensitivity to multiple stressors and rapid response to habitat changes throughout the event
Aerosol pollution, including eroded soils, intensifies cloud growth, precipitation, and soil erosion: A review
No full textThe Earth's critical zone is vulnerable to atmospheric aerosol pollution due to aerosol impacts on cloud microphysics, precipitation characteristics, soil erosion, and the subsequent interactions of the soil-vegetation-atmosphere transfer of water, energy and aerosols. This review explains the individual and inter-connected processes of aerosol loading, cloud microphysics, precipitation characteristics, and soil erosion. A by-product of soil erosion is the generation of additional atmospheric aerosols, as well as the enhancement of surface erosion due to increased runoff. The literature includes empirical and theoretical studies within and across these domains. Case studies from China and Italy are provided to illustrate the key concepts connecting this system. The knowledge of the multiscale-impacts of aerosol pollution enables actions toward cleaner production processes to reduce aerosol pollution as well as forest and vegetation management to reduce soil erosion vulnerability. This review provides our community new insights on how to assess and manage earth's critical zone and our energy, food, water, and human resource
Seasonal variation in cascade-driven hyporheic exchange, northern Honduras
No full textA characterization of hyporheic exchange for dry and wet season baseflow, as well as partially dewatered discharge, was done in Prieta Creek, a first-order cascade in northern Honduras. The cascade had discharges from 1 to 15 l s-1, had average slopes of 12%, pool spacing of 3 m, and shallow substrate of sand and gravel. Tracer tests were conducted in a 15-m sub-reach, a length considered to be adequate for the experiment based on the DaI test, a ratio of exchange and transport processes. In the three tests, between 9 and 18% of tracer was not recovered, possibly due to entrainment in flowpaths passing beneath the downstream monitoring location. Tracer data were analysed by the one-dimensional transport with inflow and storage (OTIS) transient storage model (TSM) to derive standard exchange parameters, and by the solute transport in rivers (STIR) model to examine hyporheic residence time distributions (RTDs). The best fit of the observed tracer breakthrough curves was obtained by using the STIR model with a combination of two exponential RTDs to represent hyporheic retention. With increasing discharge, the OTIS model predicted increasing storage exchange fluxes and exchange coefficients and decreasing storage zone areas and transient storage times, which are trends supported by riparian and streambed piezometric head data. Riparian water levels rose during the transition from the dry to wet season, which could constrict the hyporheic storage zone. Thirteen of the 19 streambed piezometers recorded seasonal changes in hydraulic gradients and flux direction, with fewer yet stronger upwelling zones during higher discharges. The MODFLOW model missed the observed seasonal changes, possibly due to subtle changes in the seasonal change in water surface profiles. We conclude that partially dewatered dry season exchange, compared to wet season exchange, was initiated and terminated with smaller pressure gradients and, in different streambed locations, was smaller in volume, had longer residence times, and may connect with deeper and longer flow paths. © 2010 John Wiley & Sons, Ltd
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